A procedure to align the built environment with ecosystem integrity

Material Information

A procedure to align the built environment with ecosystem integrity
Hansen, Verle Edwin
Publication Date:
Physical Description:
ix, 207 leaves : illustrations ; 28 cm


Subjects / Keywords:
Ecological integrity ( lcsh )
Architecture -- Environmental aspects ( lcsh )
Architecture and society ( lcsh )
Architecture and society ( fast )
Architecture -- Environmental aspects ( fast )
Ecological integrity ( fast )
bibliography ( marcgt )
theses ( marcgt )
non-fiction ( marcgt )


Includes bibliographical references (leaves 200-207.).
General Note:
College of Architecture and Planning
Statement of Responsibility:
by Verle Edwin Hansen.

Record Information

Source Institution:
|University of Colorado Denver
Holding Location:
Auraria Library
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
50742066 ( OCLC )
LD1190.A72 2002d .H35 ( lcc )

Full Text
Verle Edwin Hansen
B.ARCH, University of Colorado at Boulder, 1971
M.ARCH, University of Colorado at Denver, 1998
A thesis submitted to the
University of Colorado at Denver
in partial fulfillment
of the requirements for the degree of
Doctor of Philosophy
Design and Planning

2002 by Verle Edwin Hansen
All rights reserved

This thesis for the Doctor of Philosophy
degree by
Verle Edwin Hansen
has been approved
Willem vanVliet
April ?). ?007

Hansen, Verle Edwin (Ph.D., Design and Planning)
A Procedure to Align the Built Environment with Ecosystem Integrity
Thesis directed by Professor Raymond G. Studer
This dissertation develops a procedure to enable development of the socio-physical
environment without excessive losses to natural functions and processes by minimizing
initial biophysical losses, altering the temporal and spatial scales of socio-physical
disturbances, restoring compromised ecosystems, and altering the form of the built
environment. This procedure utilizes ecological criteria derived from scientific literature
to establish minimum requirements for maintaining ecosystem processes and functions
that can then be used to guide the placement and creation of socio-physical
development to assure physical conditions that support natural process. In doing so, it
provides a procedural link between natural process and sustainable human existence,
changes the strategy for protecting nature from a reactive to a proactive stance, and
defines the limits of appropriate interventions into natural systems.
This abstract accurately represents the content of the candidate's thesis. I recommend
its publication.
Raymond G. Studer

I wish to extend my sincere thanks to my advisor, Raymond G. Studer, who has
provided encouragement and review of the entire evolution of this dissertation
including its many proposals and drafts, and to my committee who upon their many
reviews of my work has guided me in making appropriate decisions and provided
needed resources. I also express gratitude to the capable faculty and staff of the
University of Colorado at Denver and Boulder, my fellow Ph.D. student cheering
section, and the director of the Ph.D. program in Design and Planning, Willem vanVliet,
for their unfailing belief in the value of this project, my ability to complete it, and
generous support and kindness. Colorado Aerial Photo Service, the City of Boulder,
Colorado, and Michael O'Neill of the City of Boulder deserve recognition for their
support in providing aerial photographic coverage of study areas and releasing their
copyrighted material for use within this document. Thanks also go to Martha Avery for
challenging me to apply this procedure to a site, the use of which is highly regulated,
and for providing base materials for study of this site.
With joy and love I give thanks to my wife, Cheryl Staats, for enjoying this educational
experience with the same enthusiasm as I have. I acknowledge my parents for their
roles in beginning this quest: my late father, LaVerne 'Vernie' Hansen, for sharing his
unrealized dreams of a higher education and assuring me that there were no limits to
what I could achieve; and my mother Helen Hansen who began my education with two
important lessons, "You can make life what you want it to be", and "You get out of life
what you put into life." Neither she nor I could have imagined that the rewards would
be so great.

1. INTRODUCTION............................................................1
Interventions Compromise Ecosystem Integrity........................1
Relatively New Problem.......................................2
Biotic Losses Cannot Be Ignored..............................4
Ecological Imperatives Set Design/Planning Criteria..........7
A Design/Planning Procedure for Biophysical Assurances..............8
Biophysical Assurances and the Design Disciplines............9
Limitations to Study........................................11
Outcomes of Study...........................................11
2. REVIEW OF THE LITERATURE...............................................12
Previous Approaches to Biophysical Losses..........................12
Limitations of Previous Approaches..........................15
New Approaches to Assuring Biophysical Conditions...........17
Planning Process...................................................22
Perpetuating Evolutionary Processes.........................23
The Concept of Restoration..................................24
Applicable Theory..................................................26
Historic Concepts...........................................26
Why Restorations over Other Concepts........................27
Physical Attributes Within the Purview of Design Disciplines.28
Possible Design and Planning Responses......................30
Inappropriate Use of Restoration............................35
Lessons from the Literature........................................36
Proactive Approach is Justified.............................36
Biological Limitations Set the Stage........................37
Inadequacy of Science.......................................38
3. RESEARCH STRATEGY AND METHOD...........................................39
How the Procedure Was Developed....................................40
Adequate Species Composition and Abundance..................40
Requirements of Native Species..............................41
Restoring Physical Conditions that Support Native Species..........55

Implementing Compatible Socio-physical Form..................56
Design/Planning to Assure Ecological Conditions..............58
4. APPLICATION OF THE PROCEDURE.............................................63
The Procedure........................................................63
Case Study No. 1 Land Unit Scale Grassland Ecosystem............65
Description of Study.........................................65
Survey Documenting the Study Area..........................66
Ecological Evaluation........................................70
Socio-Physical Development Interventions.....................70
Effects of Socio-Physical Disturbances.......................72
Case Study No. 2 Local Scale Grassland Ecosystem................80
Description of Study.........................................80
Survey Historic Range of Variability.......................81
Ecological Evaluation........................................85
Effects of Socio-Physical Disturbances.......................86
Case Study No. 3 Landscape Scale Grassland Ecosystem.............98
Description of Study.........................................98
Survey Historic Range of Variability.......................99
Ecological Evaluation.......................................103
Effects of Socio-Physical Disturbances......................108
Case Study No. 4 Local Landscape Scale Urban/Forest and Forest
Meadow Ecosystem....................................................116
Description of Study........................................116
Survey Historic Range of Variability......................118
Ecological Evaluation.......................................119
Case Study No. 5 Local Landscape Scale-Ponderosa Pine Forest......130
Description of Study........................................130
Survey Historic Range of Variability......................131
Ecological Evaluation.......................................133
5. FINDINGS AND DISCUSSION.................................................144
Findings from Case Studies..........................................144
An Adaptive Process.........................................148
Applying the Procedure to Grasslands................................151
Applying the Procedure to Forest/Meadow Ecosystem...................152
Design and Planning Responses.......................................153

Less Rich Patches........................................153
Higher Contrasting Adjoining Patches.....................153
Anthropogenic Threats to Viability.......................154
A Question of Rights............................................155
Questions of Value..............................................156
Restoration Costs........................................157
6. SUMMARY AND CONCLUSIONS.............................................164
Characteristics of Disturbances and Biotic Losses...............165
Socio-physical Adaptations to Biophysical Losses.........165
A Performance Based Objective............................167
Tractability of Procedure................................171
What Has Been Added to the Body of Knowledge....................174
A. Research Questions or Issues.........................................1 77
B. Historic Range of Variability
Grassland Flora and Fauna Land-Unit Scale..........................180
C. Historic Range of Variability
Grassland Flora and Fauna Landscape Scale..........................183
D. Historic Range of Variability
Mountain Forest and Meadow Flora and Fauna Landscape Scale.........186

4.1 Land-Unit Scale Aerial Photograph Grassland Ecosystem................77
4.2 Land-Unit Scale Site Development Grassland Ecosystem.................78
4.3 Land-Unit Scale Site Analysis Grassland Ecosystem....................79
4.4 Local Landscape Scale Aerial Photograph Grassland Ecosystem.........92
4.5 Local Landscape Scale Natural Area Inventory Grassland Ecosystem....93
4.6 Local Landscape Scale Restored Natural Area Grassland Ecosystem.....94
4.7 Local Landscape Scale Natural Area Measurements Grassland Ecosystem.95
4.8 Local Landscape Scale Public Lands Inventory -Grassland Ecosystem.....96
4.9 Local Landscape Scale Gap Analysis -Grassland Ecosystem...............97
4.10 Regional Landscape Scale - Coverage Area -Grassland Ecosystem...........113
4.11 Regional Landscape Scale - Protected Areas -Grassland Ecosystem.........114
4.12 Regional Landscape Scale - Corridor Widths Grassland Ecosystem........115
4.13 Local Landscape Scale Aerial Photograph -Forest/Meadow Ecosystem.....126
4.14 Local Landscape Scale Riparian System Forest/Meadow Ecosystem......127
4.15 Local Landscape Scale Physical Constraints Forest/Meadow Ecosystem.128
4.16 Local Landscape Scale Connectivity Forest/Meadow Ecosystem.........129
4.17 Local Landscape Scale Aerial Photograph Ponderosa Pine Ecosystem...140
4.18 Local Landscape Scale Site Ponderosa Pine Ecosystem................141
4.19 Local Landscape Scale Drainage System Ponderosa Pine Ecosystem.....142
4.20 Local Landscape Scale Protected Areas Ponderosa Pine Ecosystem......143

"The well-adapted parasite not only does not destroy its hostit actually develops
exchanges or "feedbacks" that benefit both itself and its host so that both may thrive.
And so it must be for the well-adapted, sustainable city (Odum 1993:16)."
Interventions Compromise Ecosystem Integrity
Human interventions in natural systems are unavoidable, but they compromise
ecosystem integrity and threaten human and non-human life. Biological diversity is lost
where land use changes the natural landscape and precludes its recovery. Development
of the built or socio-physical environment leaves less land to support native species,
alters species opportunities, and increases competition for resources that favor non-
native species. Thinning of natural vegetation and increased edges due to fragmentation
of natural areas by roads and structures allow solar radiation to reach the ground and
subsequent drying of the forest floor. This further reduces native species and processes
that can be supported, and alters natural energy cycles. When biotic losses compromise
natural process and function, ecosystems transform to an ecology that is supportable by
the new conditions. Lost in the transition are natural resources and services that life
requires for survival. Fewer natural resources support fewer individuals that weaken
species viability and increase extinctions. The use of more land to produce more food
and material for human use and the connectivity to and between urban areas for their
distribution further fragments and shreds the biophysical environment and limits its
ability to support natural process. Natural processes that support human life are thus
fractionalized when human need for them is increasing. The intertwining of human and
non-human lives subjects reasoning beings to ethical and instrumental considerations of
all life and necessitates a cooperative rather than adversarial relationship with nature
that is possible through the intentions of only one species, Homo sapiens.
Although not everyone agrees with a moral obligation to give appropriate respect for all
life or what appropriate respect is, few would disagree that a moral responsibility
extends to all humanity. Therefore, instrumental concern alone dictates that use of the
natural environment does not threaten its ability to sustain human life. However, the
need to maintain a larger human population and dramatically improve living standards

for millions of people increases the collective human impact on the biophysical
environment and leads to greater ecological destruction. Because natural processes
alone have proven capable of providing a healthy environment necessary for the
physical well being of all, it is prudent to determine strategies for creating the socio-
physical environment without loss to ecosystem integrity. Because the outcomes of such
interventions are potentially so dire and a relationship between humanity and the
natural world is unavoidable, it is essential to determine a balance between human
interventions into natural systems and carrying capacity of the natural environment.
Appropriate intervention into natural systems depends upon what the character of a
'good' relationship between humanity and the natural environment should be. If, in
Carolyn Merchant's view, the greatest good for human and non-human communities is
in mutual living interdependence, then this 'good' is characterized by: an equity
between human and non-human communities; moral consideration for both; respect
for biodiversity and cultural diversity; inclusion of all perspectives in the work of ethical
accountability; and an ecologically sound management consistent with the continued
health of both human and non-human communities (Merchant 2002). Ideally,
interventions that exemplify this 'good' would expand the concept of 'self' to include
the environment that fosters it and attempt to make living an art that is indistinguishable
from the components and systems that make life possible.
Because the design disciplines are integrally involved in intervening in natural systems to
make living an art, they directly affect ecologically sound management consistent with
the continued health of both human and non-human communities. Continued health of
all communities implies the existence of physical conditions that make natural process
and function possible and interventions that assure those physical conditions exist. If the
design disciplines are to be able to make ecologically sound recommendations: they
must be able to know what conditions are ecologically sound for any area that designers
and planners affect; what communities their work would affect and what physical
conditions are necessary to sustain those communities; and the ability to derive a
strategy for meeting those conditions. This dissertation provides the design disciplines
with a procedure to determine sound ecological conditions and make design
recommendations to align the built environment with ecosystem integrity.
Relatively New Problem
Ten thousand years ago, a shift in life strategies from nomadic to sedentary made
possible by domestication of plants and animals separated humanity from some of
nature's capriciousness. Adopting a sedentary existence made it possible to survive
periods of drought, shape the land to increase food production, develop water

resources, and accumulate tools and possessions that made life easier with less risk. A
sedentary lifestyle enabled the human population to no longer be limited by the
amount of available biota that can be reached and consumed by people, but by the
amount of resources that can be produced, stored, and made accessible to consumers
on a continuing basis. With risk moderated, Homo sapiens was able to prosper and
proliferate, but at elevated cost to the natural environment. A human existence
compatible with biotic systems has been supplanted by the size of the human
population and its needs. Although it is still possible for isolated nomadic tribes of
people to coexist with wild nature, it is not possible for all of humanity to be nomadic.
A large nomadic human population would quickly overwhelm available resources and
die back to a number that was supportable by natural productivity, and few native
species would survive because humanity is capable of using all available resources
leaving little to support other life. It is not only impractical for sedentary human
existence to dramatically change course, human life strategies are firmly entrenched and
inflexible to change.
Ecological losses due to a small human population subsisting in isolated patches of a
large natural matrix are usually insignificant and often repairable by natural process.
However, cumulative losses due to a large human population with geometrically
multiplying demands upon the biophysical environment shift the matrix away from a
natural order toward one imposed by human influences that do not support natural
process and function. Although technology may be utilized to maintain some of these at
great cost, only photosynthesis can produce food. Technology is further limited by lack
of knowledge concerning natural process, functions, and interrelationships with other
life. Therefore, we often do not know what needs to be maintained or how it is to be
The conflict between the socio-physical and biophysical environments exists for two
reasons. First, the threat to human life has never been perceived as an imminent and
urgent threat that demanded that we change our manner of socio-physical
development to meet ecological goals. Second, it has never been possible for human
society to establish ecological minima or mandate their maintenance in socio-physical
interventions. Prior permanent ecological shifts due to loss of ecological resilience
vividly demonstrate that thresholds exist, but clearly defining where they are has yet to
be established for any single kind of ecosystem; moreover, thresholds vary across
different kinds of ecosystems. Without knowing ecological thresholds or having an
alternative to intervening in natural systems, no argument is powerful enough to stop
activities that demonstrate fulfillment of clear and immediate human need.
Environmental philosophers have advocated saving natural systems based upon
arguments that confer moral and intrinsic value to ecosystems or species they contain,
but those arguments have little strength against present short-term human need without
alternative ways to meet their needs.

There are no innate incompatibilities between biophysical environments and socio-
physical environments. Humanity has coexisted with wild animal species in native
ecosystems for thousands of years. Differences exist because people do not want to be
vulnerable to nature's capriciousness and have placed a higher value upon human life
than for other species and are unwilling to accept human losses. Ironically, socio-
physical environments are often constructed in areas where natural hazards present the
greatest risks to human life and property. Land in floodplains, for example, is a natural
hazard to human life and property and valuable to a large number of native species, but
it is also productive for agriculture and the presence of surface water is attractive for
human settlements. Conflict arises because land areas that present dangers to people
also present opportunities that partially offset potential but uncertain risks.
Biotic Losses Cannot Be Ignored
There is a connection that must be made between loss of native species and loss of
natural process and function. Proving the loss of natural processes and functions rests on
documented transformation of one ecosystem to another with fundamentally different
characteristics. Dramatic occurrences of desertification in Africa, or rainforests in Brazil
dramatize the overwhelming effects that people can have on ecosystems. Although
ecosystems have sometimes changed rapidly, such transformations are a result of
incremental changes over long periods that lower ecosystem resilience and become
visibly noticeable only when the ecosystem is stressed beyond its ability to recover.
Because we cannot yet determine what losses any ecosystem can tolerate, it is
necessary to monitor species losses that play functional roles in ecosystem processes.
Species losses can be more easily monitored and their losses warn of possible loss of
ecosystem integrity. Biotic changes that occur rapidly or over the course of several
generations are equally insidious, and their causes are often snarled. For example, the
'Dust Bowl' in the United States during the 1930s was a result of drought, but because
grasslands often survive drought, dry conditions do not explain why the Great Plains was
so dramatically affected. Such explanation is more appropriately attributed to many
contributing causes:
1. Purchase of New France (The Louisiana Purchase) by the Federal government
that wanted this land for economic and population growth.
2. Federal mapping expeditions that prepared the Louisiana Purchase for
3. A supply of immigrant settlers fleeing overcrowding in Europe and eager to take
advantage of opportunities in a new land.
4. The loss of a keystone species, the bison, on the Great Plains to supply meat for
workers building the railroads.

5. The Homestead Act of 1862 that allowed only 160 acres per homestead of
which a minimum of one-quarter had to be plowed, was appropriate for the
Mississippi Valley, but not for the arid Great Plains.
6. Introduction of cattle and fencing of the Plains in 1860s and 1870s with
different grazing patterns from native bison.
7. Illegal fencing of public lands by ranchers between 1874 and 1885.
8. The railroads encouraged ranching and farming to provide a customer base.
9. Land use as dry land farming after winter weather decimated ranching.
10. A few wet years with high farm yields encouraged farming that was
unsustainable in dry years.
11. Overgrazing and unauthorized use of public land combined with weak
The causes may be obscure, but the devastation of the land and its native inhabitants
was not. Blowing topsoil from the Great Plains obscured the sunlight in Washington,
D.C. If the bison would have been still present, they could not have exited on dust and
land devoid of vegetation. Prior to 1883, 75 million bison roamed the Great Plains from
Mexico to Canada. By 1883, bison were reduced to 10,000 individuals (Allaby
1996:244). Although hunting is generally blamed for the drastic decline and played a
big contributing role, loss of habitat from European settlement, fragmentation of historic
range with fences, roads, railroads, farms, and the loss of birthing grounds that were
constantly occupied by settlers likely had a profound negative impact on the bison
population (West 1995). Simultaneously, all game animals and wildlife that were
considered threatening to life, livelihood, or property were either precluded or their
numbers were greatly reduced from ranges occupied by people. Grizzly bear range, for
example, has been reduced to a mere 2% of their range in the contiguous United States
(Chadwick 2001:3). Two hundred years ago, approximately 116,000 grizzly bears lived
in the lower 48 states. By 1975 there were fewer than 1000 due to hunting, habitat
fragmentation, and isolated populations (Chadwick 2001:8). The mountain lion has lost
one half of its native habitat across the western United States (Press 2001). The swift fox
has disappeared from two-thirds of its historic range over the last century (Gerhardt
2001). These cases are not unusual. Of more than 200,000 native species of all biota in
the United States, at least 500 have become extinct primarily due to habitat loss, and
approximately one-third of remaining native species in the U.S. are at risk of becoming
extinct (Press 2000). Worldwide, extinction threatens 11 percent of bird species, 25
percent of mammal species, and 34 percent offish species (Braile 2000).
Rapid growth of the human population underlies most ecological loses. There is cause
for concern about future losses because human population growth is expanding
exponentially in an environment of finite resources. The greatest risks to biodiversity are
in developing countries where population pressures are greatest and proximate to areas
rich in biodiversity. However, environmental impacts of people in developed countries

are growing exponentially because people in developed countries require greater land
areas to support their lifestyle than people in undeveloped countries. Because Earthly
biomes are all connected and interact, losses in one landscape often dramatically affect
others. Resource production and use to fulfill human needs and expectations combined
with land area necessary to accommodate the collective human population is
responsible for numerous environmental ills (Carver 1988):
1. Air pollution that is so visible over many urban areas also threatens life
worldwide. Ozone depletion increases radiation that threatens plant and animal
life. Acid rain damages plants that are necessary for primary production,
cleaning the air, and oxygen production. It also kills fish and other biota.
2. Water pollution from fertilizers and urban runoff increase sedimentation and
alters waters that produce fish.
3. Water diversion changes local ecologies by providing resources to biota that
would otherwise be unable to exist and removing resources from areas that
once supported large species assemblages.
4. Ground and ground water contamination from toxic chemical and radioactive
wastes can not only kill much life (including human), it can also alter genetic
5. Deforestation to create arable farmland and fuels eliminate habitat for
thousands of species, expose the land to erosion and soil loss, landslides, and
6. Desertification due to prolonged droughts, overgrazing, harvesting of trees for
firewood to serve larger human populations eliminates opportunities for some
species and offers opportunities to a few others.
In 1950, seventy million people lived in American urban areas covering 13,000 square
miles. By 1990, one hundred forty million people lived in American urban areas
covering over 60,000 square miles (Mitchell 2001:55). Urban sprawl in the United
States consumes 1.2 million acres (486,000ha) of farmland each year (Mitchell
2001:58). By 2025, the population of the United States is expected to reach 333
million and require 30 million new, mostly single-family detached suburban houses
(Mitchell 2001:58). Land areas required to support each individual in the United States
is 30.2 acres or 1.9 billion acres (770,553,000ha). By the year 2050, the population of
the United States is expected to increase to 393.9 million people. Worldwide, as of
1998, the human population rose by approximately 230,000 individuals each day, or
84 million for the year (Reid 1998:58). If they were all from developing countries and if
land area requirements remain constant at 5 acres per person, 420 million acres (171
million ha) would be required. If they were all from the industrialized countries where
each person requires an average of 20 acres, 1.7 billion acres (about 700 million ha)
would be required. Because there is a finite amount of land area on this planet, land
area to support this population must come from land that presently supports non-

human life. Much of this land remains productive in crops that to some extent provides
resources and services that native ecosystems provided. However, much of it is paved
over or built upon. In the United States alone by the year 2050 at current land area
requirements per person, the people of this country will require almost 8 billion acres
(3.2 billion ha) to support people. By any standards the impacts on ecosystems and the
potential losses to natural systems and their composition is likely to be great. If we do
not begin to address this problem in a proactive manner now, then it may be too late
for much of what we value and require for human existence.
By 2050, 26 million acres (10.53 million ha) or an area 200 miles X 200 mile at present
land use trends will be developed to accommodate an additional 48 million people in
the western United States (Aguilar 2001). During the same time, Colorado's population
is expected to grow by almost 2 million people. Although 77 percent of that growth is
expected to be in urban areas, 33 percent is expected to be on land areas of half-acre
to 10-acre lots (Aguilar 2001). If land lost to development were consistent across the
western United States, Colorado's share would be expected to be 1.1 million acres
removed from farmland or natural area. However, because food production would
need to increase to support the higher population, lost agricultural land would have to
be made up by higher food production per land unit or natural areas will be converted
to agriculture production. In Colorado during the 12year period from 1986 to 1998, the
land covered by impervious surfaces in Denver, Westminster, Lakewood, and Aurora
increased 32 percent from 125,500 acres (50,828 ha) to 166,000 acres (67,230 ha)
(Stein 2001). The losses to natural process and function can only be abated by careful
use of the land and placement of socio-physical development such that it posses
minimal threat to native ecology.
Ecological Imperatives Set Design/Planning Criteria
The intractable nature of ecological minima necessitates that design and planning
determine alternative strategies for socio-physical development to assure those
minimum condition. If planning and design were based upon knowledge of biotic
systems and ecological thresholds, interventions could be planned to occur when native
species are inactive and would not be disturbed, contained outside spatial areas
required to maintain minimum viable populations of native species, and to retain
energy flows, evolution, and normal species behaviors. Because ecological minima are
based on biophysical environments that functioned without human influences,
interventions that create the socio-physical environment must use the historic range of
variability (HRV) to restore physical conditions that must be in place for natural process
and function to be maintained. Ecological minima could define the native assemblage
that should be restored, and by extension, define the physical conditions that meet

native species morphology, physiology, and behavior. The possibility of stabilizing and
reversing biotic losses rests on our ability to make socio-physical interventions into biotic
systems that do not become permanent and to relinquish control over the biophysical
environment to allow natural process to resume dynamic trajectories that would have
been in place had native systems retained their autonomic structure. If anthropogenic
disturbances were temporary, they would have the same characteristics of most natural
disturbances and would allow recovery of native components, and their ability to
survive under pressure from socio-physical environments.
All earthly resources are shared by extant life forms and governed by the laws of
thermodynamics. All life is capable of adapting to changing physical environments over
time if viable populations can be maintained over a long enough time. However, the
rate of socio-physical development is too rapid for adaptation, and losses eliminate
population viability. Because Homo sapiens is the only species capable of reason and
other life is not flexible to changes we impose, it is our responsibility to limit human
impact within tolerable limits or to restore conditions that assure that native species are
minimally affected by human actions. That responsibility is expressed in human
individual and societal behaviors. Economic, philosophical, political, and scientific
institutions are all capable of addressing responsible human actions, but design and
planning are society's agents of change and are able to define a physical condition as
interim and final states of being before changes are initiated, and discover and propose
alternatives to unacceptable future outcomes.
A Design/Planning Procedure for Biophysical Assurances
As agents of change, the design disciplines directly affect ecosystem integrity, but they
lack the tools necessary to prevent ecosystem losses or to make decisions appropriate to
maintain ecological requirements. Guidance instead focuses on preserving remnants of
native ecosystems and there is little guidance how to deal with ecosystems already
changed. The design disciplines are rarely required to anticipate ecological thresholds
and conditions of survival, or to restore and maintain ecosystem integrity. Only large-
scale developments need to comply with federal and state environmental requirements,
and then only wetlands larger than 10 acres and 'endangered' or 'threatened' species
are considered. Habitat assessments when required are well organized and directed at
preventing or mitigating impacts from socio-physical development, however, they are
related only to the development site and the immediate surrounds. Consideration of
ecosystems supported by the proposed development site or how the particular site
functions in relation to species with broad temporal and spatial contexts are ignored. An
ecologically progressive community such as Boulder, Colorado, requires habitat
assessments only when city staff determines they are required and then only on the
proposed development site and to a distance of 300 feet from the site boundary. If

habitat assessments are required, they are to be done by a "qualified biologist." The
intent is to incorporate good science into the process, but it excludes the design
disciplines from involvement in finding solutions and relegates them to mitigation
procedures. The design disciplines are charged with initiating change to the biophysical
environment to create the socio-physical environment. Without their involvement in
decisions that assure physical conditions that sustain ecosystems, ecological losses might
needlessly occur and require years of work by scientists to undo damage that might
have been avoided or minimized with appropriate forethought.
Biophysical Assurances and the Design Disciplines
Losses to biotic systems that are caused by anthropogenic disturbances signify a failure
to respect either an intrinsic or utilitarian value of all life. Because all life exists in a
nearly closed system that is always at risk from human interventions, biotic systems
require care to remain healthy and able to supply resources and services that all life
requires. Recovery of ecological minima lost in the creation of the socio-physical
environment is not only expedient; it attacks the problem where the threat is growing.
Ultimately the responsibility to consider the health of biotic system upon which we all
rely belongs to every person, but burdens the shoulders of some more than others.
Those who play principal roles in changing ecosystems should be instrumental in
assuring their future. As agents of society, the design disciplines initiate change and
could be involved in assuring the maintenance of evolutionary processes. As
representatives of human interests, the only course of action is to consider all factors
that influence those interests.
The design disciplines are inextricably engaged in the process of finding fit
environments and adapting them to people (McHarg and Steiner 1998:181). This
connection was recognized in 1970 when the National Environmental Policy Act
mandated the use of "the environmental design arts" in federal decision-making that
institutionalized environmental design into federal bureaucracy (McHarg and Steiner
1998:90). The rationale for including ecological minima in the design process is at least
as compelling.
1. "Every possible future landscape is the embodiment of some human choice
(Nassauer 1997:5)." Human culture is integral to making right choices. "Only
public or private owners of land, homes, and businesses can decide to design
and manage their landscapes to contribute to ecological quality (Nassauer

2. The design disciplines have the responsibility to fit environments and adapt
them to people (McHarg and Steiner 1998:181). Because of the necessary
services and processes provided by biotic systems, losses to the biotic
community are not in the best interests of humanity now or for future
generations. Fulfilling its responsibilities requires the design disciplines to at least
compare planning outcomes, natural outcomes, and unplanned human impacts
on natural process (Forman 1995:445).
3. Preserving ecosystem integrity is both an ecological construct and an ethical
construct that cannot be avoided by the design disciplines. "Ethics impels us to
consider an area in its broadest spatial and temporal perspectives (Forman
4. The special abilities of the design disciplines create special roles of advocacy.
Because the design disciplines also receive special benefits from society and the
environmental commons, they have a duty to do no harm. This duty compels
them to act when there is reason to believe that an action prevents a greater
harm than its alternatives (Shrader-Frechette 1996:914).
5. Because humanity acts on what it likes (Nassauer 1997:8), the aesthetic aspects
of nature, where design resides, may provide the motivation to change human
6. "Romme's and Karasov's accounts of cases of land-planning dilemmas and their
potential resolution support the possibility that people can make nature part of
human settlement if they know how (Nassauer 1997:8)."
7. "Integrating human activity into preservationist philosophy...makes practical
sense, because completely excluding human impact from natural reserves has
always been very difficult and is now becoming impossible due to increasing
human populations, air pollution, and global climate change (Primack
1998:17)." "There is simply no way to 'protect' nature from human influences,
and those influences must be taken into account in planning efforts (Meffe et al.
Because most land area will never be protected by public policy and 'at-risk' species
will inevitably be in these areas, there is no chance of assuring ecological settings unless
protection is applied on all lands (Primack 1998:479). As instruments of change, the
design disciplines have access to private land and can influence land use decisions. If
we lack the will or ability to live sustainably, then perhaps we can design to retain
ecosystem characteristics that human actions would otherwise destroy. This dissertation
develops a procedure that enables the design disciplines to find and utilize relevant
ecological data and to engage it in assuring physical conditions that sustain natural
process and function.

Limitations to Study
Because human interventions are pervasive wherever they occur and natural systems
follow natural boundaries rather than human imposed boundaries, this procedure is
applicable to all socio-physical interventions in all landscapes. Even though human
intervention into seascapes is extensive, design and planning plays a more predominant
role in landscapes. Therefore, the focus of this study is confined to land areas. It may be
possible to apply some of the main concepts established in this study to direct socio-
physical development of seascapes, but that application is omitted from this study, as
are icecaps.
Outcomes of Study
This research provides a procedural link between socio-physical interventions and
sustainable human existence. A procedure for consideration of biotic systems and socio-
physical environments together would make it possible to reestablish previous
functional ecosystems to continue their maturation by natural process and adaptation to
changing natural conditions. A practical outcome for design and planning is the ability
to accommodate ethical and instrumental considerations of natural landscapes. This
procedure is usable in four ways. First, it provides a comprehensive ecological
perspective for making design and planning recommendations and for directing public
policy regarding the biophysical and socio-physical environments. In doing so, it gives
purpose to open space acquisitions, planning board decisions, infrastructure
development, urban growth, land-use changes, and use of public space without unduly
compromising natural process and function. By incorporating the concept of historic
range of variability, a restoration condition can be derived from research that can
support public policy. Second, it makes possible the recovery from anthropogenic
disturbances. The ability to make informed recommendations is injected into the
process of change that seeks results that serve all life. The procedure developed herein
allows the design disciplines to create a place for humanity without permanent losses to
ecosystem integrity. It is now possible to design and plan for human needs without
compromising interests of future generations. Third, it provides a platform for research.
Socio-physical development can now become an instrument of assessing the effects of
change on ecosystem integrity and becomes the basis for new development and change
to existing development. Fourth, given that non-human life has intrinsic value, assuring
physical conditions that make all life possible respects that value and makes it possible
to consider practical outcomes of philosophical propositions.

"It is ironic that while science has shown us that we are at best minor actors in the
broader natural order, our actions lead us in the opposite direction (Crowe 1995:22)."
Previous Approaches to Biophysical Losses
Maintenance of physical conditions that support natural process and function
throughout creation and operation of the socio-physical environment is essential, but
unfulfilled. Until recently, biophysical losses in most countries have been accepted as an
inevitable outcome of necessary socio-physical development. Environmental protection
has always involved a compromise between conflicting social needs (Allaby 1996:13).
In the absence of alternative ways to serve human needs, protections are put in place
on land that has little use to humanity or are not implemented. The problem arises
because so much of the land has value to people that little is left to support native
The Endangered Species Act of 1973 is intended to protect species. Because the ESA is
based on threat, protections are not considered until a threat is established. Two
proactive approaches exist to provide protection to species. The first is a 'fine-filter'
approach to conservation that identifies areas required for each species and species
guilds, and then protects those areas. The second is a 'coarse-filter' approach to
conservation that identifies areas that support the most species, and then protects them.
Both are essential to a comprehensive plan that adequately represents ecosystem types
that support species in minimum effective populations and complete assemblages.
Species that have not been protected by reserves and are reduced below viable
populations are sometimes captured and placed in zoos to facilitate their recovery.
Species survival plans are established for several endangered species including, among
others, the American condor, the golden tamarin, Przewalski's horse, and Arabian oryx.
Species survival plans intend to restore species to their native ranges after they have
achieved viable populations. However, restoration to their native ranges is usually
impossible because sufficient habitat no longer exists. The concept of restoration has
been directed toward replenishing economically valuable resources rather than

ecosystems. Restoration of ecosystems damaged from human interventions is still largely
ignored or shunned unless it is economically beneficial in the short-term, is of little or
no cost, or mandated by law. Attempting to save species in captivity will work only for
approximately 200 species of the thousands that are endangered (Norton, et al. 1995),
and fail to address the main cause of species loss, i.e., habitat loss. Ethical concern
would also have to consider whether it is right to save endangered animals without
attempting to save and/or restore habitat where captive animals could be restored.
In America, the history of restoration ecology is embedded in conservation efforts of
three philosophical movements (Meffe et al. 1997:11). First, early romantic-
transcendental conservation in the United States is based on the writing of Ralph Waldo
Emerson and Henry David Thoreau (Thoreau 1966). Their writings in the mid 1800s
assign values and uses to nature other than economic gain and speak of nature in a
quasi-religious sense, i.e., a temple in which to commune, a place to appreciate Cod's
works, and a place to cleanse the human soul. By the late 19th century, John Muir also
professed this view and condemned the destruction of nature for material and for
economic gain. These views continue to be reflected in the work of contemporary
authors such as Gary Snyder. Second, the resource conservation ethic is based on the
utilitarian philosophy of John Stuart Mill and followers. Gifford Pinchot (c. 1900) saw
only natural resources, however, realized their limited nature and their usefulness to
humanity. As the first head of the US Forest Service, Pinchot adopted the motto: "the
greatest good for the greatest number for the longest time". This utilitarian benchmark
emphasized fair distribution of resources to consumers and lack of waste that led to the
concept of 'multi-use' resources. Pinchot saw only anthropocentric value in nature
where resources were fed into the economic machine and contributed to the material
quality of life. To Pinchot, conservation was equivalent to sustainable resource
development. Third, ecologists who understood a close connection between the
organism and the environment initiated the evolutionary-ecological land ethic. This led
to the concept of food webs by Charles Elton during the 1920's. In 1935, A.G.Tansley
expanded this concept of ecosystem to include plants and animals together in a physical
environment. Alfred J. Lotka separately developed a concept of ecosystem by
considering organismic populations and communities as thermodynamic systems. Lotka
believed that the sizes of such systems were determined by thermodynamic principles,
but little attention was paid and Lotka did not promote his ideas. Raymond Lindeman
(Lindeman 1942) is credited with bringing the idea of an ecosystem as an energy-
transforming system to other ecologists. Eugene P. Odum advanced measuring energy
flows in 1953 by publishing his model of ecological energy flow, which is applicable to
any organism (Odum 1993; Ricklefs 1996:127-129). Elton's concept of food webs and
A.G. Tansley's idea of the ecosystem as the fundamental unit of ecology (Ricklefs
1996:128) were undoubtedly familiar to Aldo Leopold during his work with the Forest
Service and was developed into an ecological land ethic in his writings published a year
after his death.

Based on Aldo Leopold's classic essays (Leopold 1949), nature is not a collection of
independent parts, but a complicated and integrated system of interdependent
processes and components. Leopold believed in a proper functioning of components
and processes to achieve equilibrium. However, that ethic was later revised because
ecosystems are not in static equilibrium. This non-equilibrium perspective is "the most
biologically sensible and comprehensive approach to conservation (Meffe et al.
1997:13)," and "...the best informed and most firmly grounded of any approach to
nature and should serve as the philosophical basis for most decisions affecting
biodiversity (Meffe et al. 1997:14)." It is also directly applicable to planning processes.
By including economic, spiritual, and social needs, "it is the only system that can
provide even moderately useful predictions about our effects on the natural world..."
(Meffe et al. 1997:14). "Any long-term security for a natural area will come about only
when it is accepted as an integral and contributing part of a broader economic and
developmental planning." (Meffe etal. 1997:14)
Protections that could have the most comprehensive effect on ecosystem process and
function would be proactive, address prior losses and fragility of remnant ecosystems,
apply to all ecosystems, provide the most temporal and spatial flexibility for changing
plant and animal communities, and be permanent and enforceable. Although
protections imply that they are defined and implemented by people, all protections
have attempted to work around people and what they would like to be able to do with
land. Previous studies are an attempt to respond to costs to society by trying to
determine just how little land and resources need to be allocated to natural systems so
that they still function. This is a dangerous strategy, because much more damage can
occur while lengthy studies are completed and tested, and it assumes that it is possible
to know enough relationships that they can be precisely defined.
The importance of applying principles of planning to serve conservation goals was
evident in Artur Clikson's work from 1938-1967 that focused on biological aspects of
planning. Clikson's theories were based first on Leopold's land ethic and second on
environmental modification guided by an environmental art that integrates experience,
knowledge, and ethics in design and development becoming an exploration of
environmental realities and values. Thus acting as agents of natural and environmental
evolution we fulfill our humanity (Glikson 1971:3). The concept of planning is so
ingrained in human culture that a place to live was nearly synonymous with planning,
"...the process of building a hogan and the formal order it imparts, in addition to
providing a place to sit while planning the next step, acts as a paradigm for
understanding and imparting order, henceforth...the domicile is seen as the
fundamental paradigm for an ordered existence" (Crowe 1995:34). Seen this way,
'planning' is inseparable from being human and therefore is a fundamental part of living

within the confines of nature and is our chief tool for survival. Degradation of the biotic
community by humanity poses the real possibility of annihilation of a large percentage
of species diversity (Meffe et al. 1997:4). "There is simply no way to 'protect' nature
from human influences, and those influences must be taken into account in planning
efforts (Meffe et al. 1997:19)." The use of design to solve environmental problems is not
new and is one of the reasons many architecture schools changed focus to
'environmental design' approximately three decades ago.
Inclusion of environmental issues in the planning process takes at least two forms. First,
environmental policy and spatial planning is integrated as practiced in the Netherlands
(Miller and de Roo 1999). Second, environmental impact assessments are required as
practiced on projects with federal funding in the United States (Blanco 1999:51).
Recovery of the environment or assuring physical condition that maintain ecosystem
integrity is not the focus of either approach although it is possible to include restorations
in both. Restorations in the United States are more likely to result from civil action than
from environmental impact assessments; however, assessments may expose the need
for restoration. Each of these has played a role in conservation planning to establish
Natural Community Conservation Plans (NCCP) and Habitat Conservation Plans (HCP).
Natural Community Conservation Plans and Habitat Conservation Plans are biological
responses to planning for preserving natural habitat remnants and the species that still
remain. Their strategy is to protect hotspots of species diversity and habitat that supports
them. The main emphasis for all approaches to preserving biodiversity is conservation.
All such strategies either protect remaining species, their natural assemblages, or the
conditions that make their existence possible. NCCPs and HCPs are a response to the
piecemeal and inefficient approach to protecting listed species. The main feature of
such programs is their broad landscape approach that treats habitat mosaics and species
assemblages as one system (Noss, et al. 1997:41).
Limitations of Previous Approaches
All efforts to preserve native remnants of ecosystems have two shortcomings. They
protect remnants of ecosystems already substantially diminished or altered by human
interventions, and/or they rely upon protection of areas that are too small to adequately
support minimum dynamic populations. Remnants of natural areas do not necessarily
fully represent natural range of variability for species assemblages or physical conditions
that support species. Biologists primarily apply planning to conserve biodiversity.
Biologist's input into the planning process is essential for a better understanding and
definition of ecological objectives and criteria that enable them to be achieved.
However, because they serve conflicting goals, scientists and the design disciplines are
at odds when they should be on the same side.

When ecological goals are considered prior to socio-physical development, they are
almost always at the subdivision scale. This assumes that addressing ecological goals
within confined administrative boundaries will be sufficient and that once considered at
this scale, any further consideration at other scales is unnecessary. However,
administrative goals across a wide range often conflict and result in increased biotic
losses. At the subdivision scale, administrative and natural boundaries seldom coincide
and have impacts well beyond the planning area. Biophysical considerations and prior
losses would have to be defined in advance of socio-physical development for biotic
goals to be met except by chance. Because they are not considered, the value of socio-
physical developed land to natural process and function usually has minimal value.
Addressing biophysical problems after socio-physical development is relegated to
science. Although scientific input is necessary to find solutions, this approach is
unfortunate because avoidance of problems is no longer an option after damage has
occurred and remedial costs are always greater. The result is that assurances that protect
ecosystem integrity are ignored. If ecological problems are detected after socio-physical
development, they are treated separately from the development process and a societal
expense rather than an expense of development. Until the National Academy of
Sciences shifted focus from protecting nature to meeting human needs within
sustainable biotic wealth (Takacs 1996:45), science took the same view as those who
initiate change, i.e., that it is inevitable and can only be addressed after the damage is
The Endangered Species Act and the Wilderness Act primarily direct protection of
ecosystems, but these legal instruments are flawed. The ESA assumes that protecting
species can protect ecosystems. Not only may this be untrue, it potentially allows losses
to levels that may be unsustainable and unrecoverable.
The Wilderness Act restricts people from ecologically valuable areas and does not
address the fact that some interventions may be necessary. This strategy is risky because
it fails to allow interventions that are beneficial and assumes that all human needs can
be met without the need to use wilderness areas. Because humanity and its effects are
not excluded from any ecosystem, this act fails to manage externalities.
The prevailing view of property rights conflicts with natural process and function.
Preservation of native ecosystems does not address what has already been lost and
there is not enough natural area left to retain complete ecosystems. Because most of the
highest quality biophysical components are on private property, any program that
ignores private property is unlikely to maintain minimum viable populations of the
assemblages they comprise or physical conditions that are necessary to maintain natural
processes and functions. Everywhere humanity has settled, environmental degradation
and destruction has been the rule (Meffe et al. 1997:7). Human ecology recounts

numerous cultures that have persisted for hundreds of years, but have degraded their
environment in recent history (Rappaport 1984; Smith 1991; Descola 1996; Sheridan
1996; Abram 1997). John Locke's concept of land use (Locke 1690) that dominates the
Western world is no longer appropriate (Narveson; Wolf 1995; Raymond 1996; Sax
1996), yet humanity continues to use land for short-term individual gain versus long-
term human survival. According to Garrett Hardin, humanity communizes the costs and
privatizes the profits (Odum 1993:275). Land and resources that Locke had perceived
as infinite are limited and must be shared by contemporary and future people and must
accommodate a growing human population. Consideration of only human land use and
rights to its use neglects biotic communities and by extension much of humanity. If
humanity cares about its own future and other life, then it must be on terms acceptable
to other life because only people respond to reason. Biotic degradation is avoidable if
nature provides the ecological boundaries that dictate human use of land and resources.
New Approaches to Assuring Biophysical Conditions
A crucial response to current and future losses of biodiversity is a conservation strategy
that is proactive rather than reactive (Meffe et al. 1997:5). This shift from a defensive to
an offensive posture is one of the main goals of the National Academy of Sciences in
supporting a global biodiversity strategy that links biodiversity with cultural diversity
(Takacs 1996:34-45). This suggests that meeting the needs of people and sustaining
biodiversity must be combined. This is convenient because a proactive stance is a
natural fit with planning strategies and therefore planning for ecosystem restorations can
be easily integrated into contemporary planning and design processes. Integration of
intelligent and informed management of disrupted ecosystems with the process of
disruption and restoration could be vital and efficient for maintaining evolutionary
processes and ecosystem functions. The goals of ecosystem management could be
included in the design/planning process to affect a socio-physical outcome that could
support natural process rather than endanger it.
A proactive approach to meeting ecological objectives should be expected and normal
procedure. Governmental agencies, such as the U.S. Forest Service, exist in part to plan.
A planning intention is indicated by its appointment of 'The Committee of Scientists' in
1997 charged with "...making recommendations on how to best accomplish sound
resource planning..." and "...provide technical advice on the land and resource
management planning process..."(Scientists 1999:ix).
Including ecological restoration in the planning process to develop the socio-physical
environment fits with the overall goals of comprehensive planning for health, public
safety, circulation, provision of services and facilities, fiscal health, economic goals,
environmental protection, and redistributive goals (Levy 1997:102-104). When any

long-term perspective for these goals is considered, humanity and biotic systems are
integrally linked. Holding fast to anthropocentric values is understandable, the challenge
is to see that valuing biotic systems cannot be divorced from that focus. Planning to
assure that goods and services necessary for all life continues requires that biotic systems
be protected. Planning decisions directly influence whether biotic systems are capable
of survival and therefore they must be considered in the planning process. Only by
protecting biophysical environments will humanity meet planning goals.
The necessity for human intervention into natural systems sets up the conditions that
degrade natural process and function. However, because disruptions are normal events
in ecosystems (Forman 1995:351-363) an opportunity is presented whereby human
interventions do not need to be detrimental to ecosystem function or components.
Habitat elimination, shredding, and fragmentation by socio-physical disturbance do not
completely explain species losses because the natural environment is often fragmented
(Meffe et al. 1997:276) with different plant species, soil and hydrologic conditions, and
serai stages. In part, they can be explained by the characteristics of disturbances. Meffe
and Carroll identified three inferred characteristics of anthropogenic disturbances that
differ from natural disturbances: less rich patches; higher contrasting adjoining patches;
and anthropogenic features and activities posing threats to population viability (Meffe et
al. 1997:278). Characteristics of socio-physical environments have distinctive ecological
structure, function, and change (Forman 1995:459) that speed up water flows, facilitate
domestic plant and animal movement through the landscape, and inhibit movement of
native species when forest cover is below 5% (Forman 1995:460). These differences
are, in essence, a loss of seres due to perpetuation of disturbances. In the socio-physical
environment the land is repeatedly plowed, cleared, grazed, paved over, occupied by
buildings, or continually maintained with exotic vegetation and occupied by people.
Normal successions are thus prevented from the socio-physical environment and
species are prevented from utilizing necessary resources. If human disturbances were
limited to the same temporal and spatial scales that an ecosystem would normally
experience, their effect would be imperceptible from any normal disturbance and could
serve the same functions. If human disturbances had short durations or existed during
the dormant months for most species, and the socio-physical environment included a
restoration of serai stages there would be no unusual or permanent disruption.
Because change is integral to the socio-physical environment, disturbances are not
permanent, but they also do not fit natural temporal and spatial patterns. In effect, the
difference is in relative duration of disturbances. Natural disturbances may take place in
a matter of minutes for severe storms, to weeks for severe floods, whereas
anthropogenic disturbances, such as urban sprawl, keep spreading out year after year
from a core area (Forman 1995:461). Anthropogenic disturbances tend to set back
succession stages to primary succession that might occur after a lava flow or sand dune
(Odum 1993:190-91). The longevity of such disturbances is that they are susceptible to

other shorter perturbations that keep succession from progressing (Odum 1993:191).
Just as lava flows and sand dunes are normal, if essentially permanent, a case could also
be made that it is acceptable for at least some of the anthropogenic environment to be
in a state of continual disturbance. The extent of continual disturbance, however, must
be governed by what is required to perpetuate natural process and maintain minimum
effective populations of all native ecosystem components. Rather than justifying
permanent socio-physical disturbances, differences in disturbances characteristics
should be used to guide acceptable disturbances and socio-physical form.
Assuring physical conditions that sustain natural process and function is subverted by
current economic and environmental degradation. According to the "Brundtland Report
issued in 1987, "Survival depends on changes now" (Odum 1993:277). Given that
sustainability is out of the question without changes, nearly any action that progresses
toward sustainability will be an improvement. Applying restoration to socio-physical
disturbances slows and reverses environmental degradation because it allows open
wounds to heal and applies universally across all socio-physical disturbances regardless
of past or future. The Brundtland Report addresses these problems by calling for
enhanced multilateralism and cooperation between nations so they can work together
(Odum 1993:277). However, it neglects to value what can be done unilaterally. There
are no approvals or agreements needed on actions that are ethically and procedurally
right, such as healing open wounds. Criticism of this philosophy, however, claims that
making it easier to restore makes it more acceptable to disrupt and because any
disruption is environmentally riskier than pristine states, disturbances are encouraged
(Katz 1992:83-93). Yeuk-Sze Lo (1999)and Robert Elliot (1982) express similar
opposition based on restorations as being artifacts and copies with less value than
original ecosystems. These criticisms miss their mark on two counts. First, the concepts
of 'original' and 'copy' are not applicable to dynamic natural systems (Robertson
2001:39). Rob Bartram and Sarah Shobrook (2000:378) seem to agree, "...nature's
reality can no longer be assumed as having an original, unitary condition." Second, they
neglect that nearly all nature is already disturbed and the assumption that it will be
further disturbed to create the socio-physical environment, and the only recourse is
restoration (Throop 1994:131; McHarg and Steiner 1998:357). Even if planning efforts
prevailed to develop much more dense settlements and to limit further urban sprawl,
ecological restoration from anthropogenic disturbance would be required because it is
inevitable that the biophysical environment is disturbed to create the socio-physical and
without healing, wounds are cumulative.
Acceptable biophysical disturbance and compatible socio-physical form may, in part, be
possible within temporal and spatial interstices. Zoological literature (Pough, et al. 1996)
is full of descriptions of animals that follow seasonal life patterns. Amphibians, reptiles,
and many mammals spend significant portions of their lives in torpor or hibernation.
Even people spend a portion of every day in sleep. Many birds, some insects, and some

larger mammals follow seasonal migrations. Many insects complete their life cycles
during a few months and begin a new cycle with offspring the following warm cycle. All
of these temporal gaps allow time for anthropogenic interventions without constituting
disturbances to species that follow cyclical life patterns. Implementation of socio-
physical interventions to coincide with temporal cycles would need to be scheduled so
that primary disruptions to ecosystems occur during dormant months rather than during
growing seasons and periods when animals are active. Ideally, the interventions would
occur only during times of species inactivity. However, even natural disturbances
exceed temporal gaps. As long as the intervention is within spatial disturbance patterns,
minimum effective area is maintained, minimum populations are maintained, and are
within normal succession stages, some longer interventions can be tolerated. This may
take a bit of getting used to. However, once the system is in place, there should be no
substantial increase in costs to implement the socio-physical environment. This assumes
that construction processes can occur during winter in temperate climates or during the
heat of the day in tropical climates. However, this is not a great adjustment to make
because disruptive phases are short lived. If care is taken to limit disturbance to small
envelopes (Wasowski 2000), disruptions to land and vegetation will be less, requiring
less landscaping and repair after implementation. Predominantly, spatial and temporal
disturbances would be defined by the species that exist within a development area or
are affected by it. This requires that extant and obligate species are known and that
literature is abundant. Walker's Mammals of the World (Nowak 1991) is a good place
to start for mammals, and there are references that deal with local species for nearly
every state similar to Mammals of Colorado (Fitzgerald et al. 1994). Similar references
exist for insects, reptiles, fish, etc., however, scientific data are incomplete for all species
and study of microorganisms is severely lacking.
Assuring physical conditions that benefit the biophysical environment is possible if it
assures land and resources that support the human population. Consideration of
ecological restoration from socio-physical disturbances leaves space for humanity in
three ways. First, it directs disturbances to take place where disturbances are least
detrimental to biotic systems. Second, it provides guidance for how to make such
disturbances where they are necessary to minimize and reverse them. Third, it provides
a vision of how we should maintain and/or direct change to the socio-physical
environment to regain what was lost in prior disturbances.
Richard Forman (1995:406-417, 426-432) assumes that land transformation inevitably
adds up to losses and that the best strategy for minimizing losses is to determine
ecologically optimum land-conversion sequences. Forman (1995:423) outlined a
sequence of appropriate mosaics and recognized the necessity of restoration (Forman
1995:432) that, taken together, point toward mosaic sequences that could also be
applied to the transformation of a disturbed environment to one that assumes varying
serai stages that are normal characteristics of biophysical environments (Clements 1916).

If true, land may be constantly transformed for anthropogenic uses, but never totally lost
to ecosystem processes. However, in any period of human occupancy that may last
from hundreds to thousands of years, there is some land that is in this period of time
removed from ecosystem productivity. Because removal of land from ecosystem
productivity is subject to socio-physical life cycles, it should be possible to renew serai
stages and thus to reverse mosaic sequences. This would allow humanity to occupy land
in changing patterns of land use that would be similar to stages of natural succession. If
development of the socio-physical environment could additionally become more
compact and dense in core areas (which is likely to become necessary as the
automobile becomes a less dominant means of transportation), then there should be
adequate space for humanity while restoring biotic systems. Experimentation is needed
to support this premise. Richard Register (1987) makes a similar thesis, but has not dealt
with the concept of applying successions and does not directly address the concept of
ecological restoration.
Space for humanity is also the product of natural or historic range of variability. If
minimum viable populations of native species can be assured in minimum dynamic
areas beyond the reach of stochastic events, native components, functions and
processes can survive without requiring the entire Earth surface. Because people are
also part of that historic range of variability, it is acceptable that part of the Earth is
apportioned for human existence.
Anthropogenic corridors, i.e., roads, utility transmission routes, railroads, etc., pose a
difficult problem because they seem to be permanent over time, expand, transform the
land on each side, and form branches that further fragment the biophysical
environment. Recovering lost land area from corridors that decay is less likely, although
Richard Register (1987) makes the claim that future intercity transit will be more by
railroad and airplane than by truck and automobile. Register's statements seem to be
more wishful thinking and speculation than science; however, he does define
possibilities for change. The solution may be accomplished by following the same three
methods listed above with modifications of approaches. Infrastructures other than roads
can be constructed to allow natural serai stages and should likely be done in segments
rather than all at once, or advanced serai stages should be restored to simulate a non-
linear disturbance. Roads and highways that are more permanent should avoid the most
biotic rich areas. They would thus be placed in the least ecologically valuable places
and across biotic rich areas where the least disruption would occur. They would thus
cease to follow riparian corridors as has been the case, and would instead traverse
riparian corridors. Each crossing would be done in a manner that avoids creating a
barrier to animals that follow riparian corridors. Where roads and highways cross animal
movement corridors that are not along a riparian corridor, roads and highways need to
be designed to allow movement to continue. Roads and highways will thus sometimes
bridge natural movement corridors or tunnel below them. Where roads and highways

exist within urban areas, they can follow the same procedures wherever possible,
become narrower, and be supplied with wildlife bridges (Primack 1998:445), as
necessary. In this manner, less land is lost to human uses, and disturbances to wildlife
are reduced.
Following ecologically based objectives that are limited by ecological thresholds
provides the physical context for making all anthropocentric design decisions. Design
and planning guidelines are definable based upon ecological criteria in at least two
formats. The first is the ecological determinants process (McHarg and Steiner 1998:43).
The concept of restoration provides a similar set of criteria to guide planning, however,
assumes that the physical context is ever changing even where socio-physical
development has already taken place. Because it assumes that the biophysical
environment is only a disturbance that is in one state of recovery, the context for
planning and design demands that design/planning decisions account for a recovery
process and the incorporation of successions.
Planning Process
Common elements of the planning process are covered by numerous authors such as
Kevin Lynch, Ian McHarg, and Frederick Steiner and follow similar steps that include:
(1) a research stage; (2) a clarification of community goals and objectives; (3) plan
formulation; (4) plan implementation; and (5) review and revision (Levy 1997:104-
111). McHarg and Steiner include much more in-depth research on the biophysical and
abiotic environments in the research phase of planning and as proposed in this thesis.
There will be some variation in planning steps depending upon planner, community,
and community context. Because design and planning responses are inherently
experimental settings constantly responding to continual disequilibria (Studer 1970:73),
there will be no final design or planning solution for any environmental problem.
Instead, each design and planning response is a probable response to a particular set of
objectives that changes the environment and thus sets up experiments for recording
changes, testing hypothesis, and making further adjustments through an evolution of
design and planning responses (Studer 1970:72-75).
Among the first items in planning research is to determine the "population forecast."
From ecological perspective, population forecast can apply to human population and its
projected effects on flora and fauna. Both considerations will emphasize the need to
plan to preserve and restore biotic systems to meet broad planning goals. Scott
Campbell (1996:296), however, claims that the concept of 'sustainability' can help
focus conflicting interests and become an organizing principle for planning. Campbell
(1996:297) is skeptical of planners because they exist within extremes of Robert Moses

and Earth First's Dave Forman and a mid-point claims no legitimacy or fairness, and
because they represent so many conflicting interests, are likely to represent one more-so
than others with environmental interests usually losing out. I have no illusions that
applying ecological restorations to socio-physical interventions will be able to resolve
the seemingly implacable political positions that arise in planning projects, however, it
can present a middle ground that can be supported by most stakeholders. Healing open
wounds does no harm and could serve the needs of both present and future
generations. However, even this approach will be opposed by all who see wildlife as
pests or dangerous and do not want their neighbors to harbor it.
Ebenezer Howard has attempted consideration of environmental issues in planning in
more modern times in his 'garden cities' and in clustered developments by Peter
Calthorpe and Sim VanderRyn who have attempted to address 'sustainable
development'. "Design of [conservation] territories in today's conservation boom is
typically generated through national planning (Zimmerer 2000:358)."
Ecological restoration has not been systematically applied to socio-physical
interventions; however, guidance is available from biological applications as outlined by
Andre Clewell, John Rieger, and John Munro (Clewell et al. 2000). They identify the
mission of ecological restoration " reestablish a functional ecosystem of a
designated type that contains sufficient biodiversity to continue its maturation by natural
processes and to evolve over longer times spans in response to changing natural
conditions." This mission is nearly identical to the objective stated at the beginning of
this chapter and in Chapter 3. This objective is achieved by two attributes: first, species
richness and community structure; and second, physical conditions that sustain these
species (Clewell et al. 2000:1).
Perpetuating Evolutionary Processes
No crystal ball can direct human decisions. Ecological and social systems are themselves
dynamic, but they also interact dynamically (Gunderson et al. 1995:xi). Their individual
and combined outcomes are unpredictable and are capable of influencing each other.
The potential result is that human action is capable of directing the course of evolution.
This would be scary enough if we knew where we wanted it to go and had some
control over it. It is terrifying to direct the course of evolution without guidance and
without control. The human challenge is to fully live while having the smallest ecological
impact so that evolutionary processes are self-perpetuating along natural trajectories.
Restoration is an essential element for perpetuating evolutionary processes because
"...sustainable development is only possible if it is seen as a process of evolutionary
change that rests on the capacity of nature and people for renewal" (Gunderson et al.
1995:6)." Renewal will not be possible if human population growth and development

continues to eliminate the biotic systems that renewal depends upon. Restoration is by
nature an intervention into biotic systems; however, its purpose is to return an
anthropogenic disturbed ecosystem to its original trajectory. Because restoration is an
intervention into unknown and dynamic territory, it will require monitoring and
adjusting to ascertain that the original trajectory is achieved. However, restoration is not
intended to be intensive management to achieve anthropocentric goals, nor does it
attempt to achieve sustainable production of food or fiber or sustainable development.
A policy of restoration accepts that anthropogenic interventions to create the socio-
physical environment will occur, but attempts to make them temporary. The work of
Lance H. Gunderson, C.S. Holling, and Stephen S. Light (Gunderson et al. 1995) deals
with problems associated with sustainable development and adaptive solutions.
Returning disturbed ecosystems to original trajectories from a design/planning
perspective must of necessity deal with ecosystems at the landscape and land-unit
scales. Assigning such small scales, however, neglects characteristics such as
concentrations of carbon dioxide levels being higher than at any time in the past
160,000 years due to anthropogenic causes, which could preclude a return to the
original trajectory. Perpetuating evolutionary processes must be placed in larger spatial
and temporal references, even though design/planning will likely deal with those
references in piecemeal fashion or at smaller spatial and temporal scales.
The Concept of Restoration
The concept of perpetuation implies that some activity is to be commenced that will
maintain a state of being. We derive this presumption from theories of ecosystem
function and the human role (non-role) in them. Restoration ecology has only recently
gained recognition as a conservation strategy (Meffe et al. 1997:479), but the concept
of restoring biotic characteristics to disturbed landscapes likely originated with
nineteenth century prairie landscape architects Jens Jensen and Ossian Cole Simmonds,
who incorporated elements with a natural appearance in their work (Throop 2000:12).
The goal of restorations was to regain natural balance lost during settlement of the New
World. The first U.S. government mandates for restoration began with the Lacy Act of
1900 intended to preserve and restore game and other wild birds (Throop 2000:12).
Shortly thereafter, ecologists began to emphasize and quantify processes of ecological
change as evidenced by the work of Frederic Clements (1916) in process of successions
(Bratton 1992:54). Government specifically made 'restoration' a goal in the
environmental acts of the 1960's and 1970's (Throop 2000:12) (Rolston 1994). One of
the earliest restoration projects in the United States was a restoration of tail-grass prairie
by Aldo Leopold in the 1930s, however, it was approximately 50 years later that
scientific interest in ecological restorations grew enough to support a restoration journal
Restoration and Management Notes in 1982, and Restoration Ecology in 1993.

Restoration remains controversial because it raises profound and unresolved questions.
Some biologists and philosophers fear that the real prospect of accomplishing
restorations would, in essence, encourage environmental destruction and ill-conceived
resource exploitation (Katz 1992; Holloway 1994).
Early restorations were based on an agriculture model or climax community model with
a goal of productivity and stability. Recent restorations are based on community
structure or ecosystem function models with a goal of biotic diversity, inclusion of rare,
endangered, and endemic species, system complexity, and natural processes (Bratton
1992:53). Because of the unavoidable huge potential antropogenic influences on
ecosystem structure, future restorations should focus on assuring conditions that support
minimum dynamic systems. Such minimum conditions can be used to guide design and
planning recommendations.
Evolutionary processes in functional settings are more likely to be perpetuated if
ecosystems that are lost in the construction of the socio-physical environment are
restored. This premise is based upon:
Public Resources/Private Lands. Because more than half of endangered species
have more than 81% of their habitat on private land (Noss, et al. 1997:26), private
land must be a focus of maintaining biodiversity and evolutionary processes.
Sustainability. Restoration ecology as applied to the socio-physical environment has
been primarily through sustainable development (Hettinger and Throop 1999:17),
(Barrett and Grizzle 1999:25), (Swearengen 1999:282).
The idea of nature restoration should be that of wounded nature being remedied.
Weakened ecological and evolutionary capacities should be recovered so that
ecosystems can sustain and self-regulate. The autonomy of nature should be
rehabilitated ... (Lo 1999:266). If the concept of restoration seems difficult at best, and
impossible at worst, that does not lessen the need for it. The human population is
growing too great to avoid significant damage to the biophysical environment and
repairing the damage is the job of enlightened management (Noss and Cooperrider

Applicable Theory
Historic Concepts
Restoration Applied to Socio-physical Environment. Accomplished restorations
of hydrologic regimes have renewed the health of aquatic systems. At the turn of the
19th to 20th century, the Thames River in London was substantially dead but has been
restored to a healthy system. By the mid 20th century the Don River in Toronto had
been channelized and straightened so that it performed no ecological processes and is
now being restored (Hough 1995:51-70). The Kissimmee River in Florida began
restoration almost immediately after channelization and is an ongoing project (Cairns
1994:49-73). Socio-physical development usually necessitates suppression of natural
disturbances that are required for evolutionary processes. Restoring or preserving native
flora and fauna in socio-physical environments, therefore requires active and ongoing
intervention influenced by native spatial and temporal frames (Parker and Pickett
Principles of Thermodynamics. Eugene P. Odum first modeled ecosystems in
contexts of thermodynamic principles: 1st law, energy may be transformed but not
destroyed; and 2nd law, energy transformation occurs only when energy is degraded
from a concentrated form to a dispersed form, i.e., entropy. These concepts were used
to explain ecological structure as exemplified by the work of James Kay (1990).
Principles of Succession. Frederic Clements (1916) was among the first people
to illustrate how the biophysical environment changes through a series of changing plant
types called succession. Succession is a normal process of recovery from natural
disturbance regimes. Essentially succession is part of a process of recovery. Clement's
view of serai stages resulting in climax communities is valuable, but not complete
because there are no accurately predicable serai stages and the 'climax community' is
still in the process of change (Allaby 1996:156,157).
Principles of Interrelationships. Aldo Leopold is credited with illustrating the
interrelationships among biotic components. Leopold recognized that nothing exists
outside of the relationships of all other components in an ecosystem and developed a
'land ethic'. Leopold's land ethic, however, needed to be revised to include a non-
equilibrium perspective to his evolutionary-ecological land ethic because ecosystems
are not static. Although Leopold was aware of nature as dynamic, he thought of natural
change as evolutionary rather than ecological (Meffe et al. 1997:51). Restoring a
dynamic ecosystem to status would not work (Meffe et al. 1997:51; Hettinger and
Throop 1999:7). Meffe et al, (1997) noted that what is "right" in Leopold's land ethic

should be modified to "A thing is right when it tends to disturb the biotic community
only at normal spatial and temporal scales. It is wrong when it tends otherwise (Meffe et
al. 1997:52)." Establishing normal spatial and temporal scales, however, will be unable
to maintain minimum viable ecological systems if the human population increases
demands on space due to rapidly increasing numbers. Therefore, from the
designer/planner perspective, a thing is "right" when the biotic community is disturbed
only at normal spatial and temporal scales and above minimum viable populations in
minimum dynamic habitats.
In natural states, the environment can sustain human life only part of the year which
necessitates human existence be maintained by wise use of time, not land. Humanity is
thus a temporal partner in ecological systems. It was only after humanity gained
knowledge of biology that it was able to create an artificial landscape that would
support a sedentary lifestyle. Humanity extends beyond our own biological makeup by
means of culture through the use of fire, domestication of animals, crop management,
and writing. It is thus able to manipulate nature to create a human-made world, and
separate itself from nature (Crowe 1995:29).
Perhaps Eric Katz (Katz 1992:85), is justly outraged that anyone would propose that
technology could create nature, but the creation of nature is not the issue. This
dissertation does not advocate the creation nature or a social utopia, but a healing
process. Once an intervention has been made into a natural system, whether by chance
or necessity, some disturbance occurs and it is better to prevent biotic destruction and
repair what has been disturbed even if it leaves a scar than to keep an open wound or
accept the loss of an autonomic system. Because planning objectives and processes are
already defined in much of the literature, it is possible to define a strategy to include
ecological restoration into the process of creating the socio-physical environment.
Why Restoration over Other Concepts
There are six strategies to preserve biodiversity based upon different sets of
assumptions: (1) Bioreserves; (2) Emphasis Areas; (3) Coarse-Filter Habitat Diversity; (4)
Historical Range of Variability; (5) Fine Filter; and (6) Coarse Filter with Species
Assessment. Each strategy is designed to: preserve all native ecosystem types and serai
stages; maintain viable populations of all native species; maintain ecological and
evolutionary processes; and manage landscapes and communities to be responsive to
change (Baydack et al. 1999:38). All preservation strategies are experimental
(Gunderson et al. 1995:9; Baydack et al. 1999:30) and applicable to design primarily as
vehicles to establish objectives. However, planning for restoration is not the same as
planning to preserve biotic diversity and therefore these strategies do not fit directly.

They are more valuable to design process if they help to define the restoration context
and what ecosystem characteristics should be considered design criteria.
Ecosystem preservation is not sufficient to recover losses already incurred and it
predominantly addresses only 'endangered' species on private land through the legal
instrument of the Endangered Species Act. This strategy assumes that protecting the
most vulnerable species protects ecosystems. Protecting endangered species does not
assure natural processes, and legal protections are theatened by legal challenges and
unwillingness of the current federal government administration to list endangered
species and to enforce the act (Wilkinson 2001). Application of the concept of
restoration to the design/planning process is preferable to other concepts of preservation
because: (1) restoration includes consideration of natural process within a process of
socio-physical development that will directly and negatively affect ecosystems; (2)
consideration of natural process at land-unit and landscape scales relies upon broader
temporal and spatial scales; (3) restoration enlists all who play roles in change and
accepts responsibility for individual action without deferring to a higher authority; and
(4) restoration addresses all incremental and cumulative change that constitute
biophysical losses.
Physical Attributes Within the Purview of the Design Disciplines
Two ecosystem attributes must be assured to maintain ecosystem integrity: adequate
species composition and abundance; and physical conditions appropriate to sustain
those species (Clewell et al. 2000:1). The design disciplines have limited control over
species composition or abundance. The most they can do is to assure that physical
conditions are appropriate for native species so native species are able to remain or
return. Physical conditions that make it possible for native species to exist are:
1. Survivability of native species requires minimum effective and viable
populations in minimum effective areas with configurations that fit physiological,
behavioral, and morphological needs of native species. Minimum dynamic or
minimum effective areas that support minimum effective and minimum viable
populations are required for all habitat types in an area. In many areas they
have been severely fragmented and must be reconfigured and united to achieve
whole areas.
2. Evolutionary challenge to physiological, behavioral, and morphological makeup
provides opportunity to utilize genetic variability. Conditions that support life
are constantly changing and require species to adapt or perish. It is therefore
not essential to meet any particular environmental condition(s), but to provide a
range generally agreeable with native species. Normal evolutionary processes
are kept working by maintaining: natural levels of plant productivity; high levels

of native biological diversity; usually very low rates of soil erosion and nutrient
loss; and clean water and healthy aquatic communities (Thorne 1993:24).
3. Intact energy flows include: historic hydrologic; disturbances that have been
adapted to; the ability to recover from disturbances; solar input; and plant and
animal connectivity and movement. Energy flows and material moves within
and between ecosystems (Thorne 1993:30). Restoring energy flows may be
accomplished primarily by manipulation of successions. It may also be restored
by removal of physical barriers to energy flow and material movement. Broad
landscape functions depend upon energy flows from producers to herbivore to
predator to top predator and material flows that either cycle within or flow in
one direction through an ecosystem (Forman 1995:76-77).
4. Natural hydrologic regimes are one of the essential and perhaps most valuable
elements of ecosystems. In nearly all ecosystems, the riparian corridors are
especially important to the lives of 85% of all wildlife, serve as primary support
for major vegetation, serves as drainage, and supports all aquatic species. They
also serve as corridors for movement of mammals, birds, and fishes, replenish
soils, and provide support for early statges of succession. Hydrologic regimes are
so basic to most ecosystems that their restoration can affect most other major
ecosystem functions.
5. Redundant connections of habitat types are necessary for movement of
individuals to assure colonization of disturbed areas, genetic variability within a
population, and to make certain that sub-populations of any species remain a
functional population.
6. Natural Disturbances are essential. The impacts of natural disturbances are often
disastrous to people who live in their paths, however, it is often the suppression
of those disturbances that create the conditions that lead to such high social and
economic impacts. Natural fire disturbances often cleaned out the understory
below the forest canopy, recycled nutrients, increased stream flow, and
provided resources that support biodiversity (Brown et al. 2001:19).
Suppression of fire disturbances combined with increased human occupation
within disturbance risk areas has increased the disastrous effects. Increased fuel
potential of the understory and dried out forest floor accelerates and magnifies
forest fires and the damage they cause. The result is not only higher loss of
human property and lives, but also greater ecological loss.
Physical conditions that support native species can be revealed principally through the
historic range of variability (HRV) for any subject land area. HRV is the most useful
target for restoration of ecological settings because it provides the most enduring models
of viable ecosystem behavior (Brown et al. 2001:20). Use of HRV models allows the
possibility for return to the autonomy to biotic systems rather than impose conditions
that will require constant maintenance (Willers 1999:2).

Possible Design and Planning Responses
An approach that focuses on the preservation and restoration of ecosystems can
establish the physical context for planning (Mazmanian 1999:57, Plat et al. 1996, Yaffe
et al. 1996). Because human existence is rooted in biophysical processes, it is possible
for design to have its conceptual base in biology (Seddon 1986:339). This strategy is
different from previous procedures in two ways. First, it addresses that portion of the
environment that has already been effected by human intervention, not just native
ecosystems that account for a small portion of Earth's land surface. The potential impact
of using this procedure, therefore, will be greater than preservation tools. Second,
preservation and restoration tools have been applied to mining and extensive U.S.
Corps of Engineers projects with little focus on changes to other socio-physical
development. Whereas restoration guidance and directives apply to mines, the far
greater and widespread impacts are due to urban, suburban, and agricultural
development. Restorations applied to socio-physical settings have utilized natural
remnants as valuable biophysical elements, but have not utilized ecological minima to
guide socio-physical development to assure physical conditions that support
In a system where every life form is governed by rules of nature, natural process and
function are an inevitable outcome of the natural course of events. As in Chaos Theory,
the accumulation of responses to a specific set of rules creates ecosystems and
maintains ecosystem integrity. However, the change of life strategies discussed earlier
separated humanity from a natural course of events to one that is imposed by human
will. An ecological goal of planning and design is to return a degraded ecosystem to a
condition as similar as possible to its pre-degraded state or its original ecosystem (Meffe
et al. 1997:482) that would maximize ecosystem structure and ecosystem function
(Bradshaw 1984). This can be accomplished by developing rules of engagement
between people and natural systems. The procedure developed in this dissertation
restores a set of criteria for human interventions into natural systems that maintain a
natural course of events to assure biophysical conditions within a given set of operating
points or changes a system's operating points to place it on its original trajectory. Design
and planning within operating points or toward an original trajectory are the only
practical alternatives because ecological restoration in most instances can only be
approximated (Meffe et al. 1997:483). Setting an actual target restoration is impractical
because an ecosystem is the result of a sequence of biotic and abiotic events that are
unlikely to be repeated, structural and functional attributes of the pre-disturbance
ecosystem are imprecisely documented, and identical biotic components may no longer
exist (Cairns 1994:6). Setting the trajectory is practical because it is dependent upon
eight preconditions that can be studied: knowledge of the original state; the known
degree of biotic perturbation from the original state; the known degree of abiotic
perturbation from the original state; availability of native biotic components; sufficient

genetic variation of available biotic components; sufficient financial commitment;
sufficient and capable political commitment; and sufficient existing science to provide
adequate guidance.
Selecting an appropriate design/planning response depends upon the type of
environment where intervention is being proposed, e.g.:
1. In ecosystems that are truly natural, no interventions should be made so as to
preserve some of the last remnants of natural areas.
2. In ecosystems with highly sensitive species and where populations of critical
food web components are significantly reduced restorations cannot be
guaranteed and improved science is necessary to define strategies that work
within existing science and begin redirecting the developmental trajectory
toward an original state. Interventions in these areas should be avoided or firmly
based upon scientific data and full evaluation of risks.
3. In areas where species remain in viable populations, one approach is to restore
the hydrology and transplant native vegetation, then wait for animal populations
to expand into new habitats [Meffe 1997 #203488].
4. In highly perturbed areas, e.g., urban areas, development of the socio-physical
environment changes previously altered states. Therefore restoring a series of
favorable traits or mimicking an original state is accomplished by shortening the
natural sequences to speed up succession (Meffe et al. 1997:492), or to hold a
biotic community in a particular successional stage. This strategy should begin
well before interventions are implemented so that biophysical assurances can
become part of the interventions, part of the final socio-physical environment,
and part of an integral and fully functional biophysical environment. This
approach may slow the implementation of the new socio-physical environment,
however, it will have a better chance of persisting, be more natural, be more
economical to achieve, and recover more quickly.
Restoration of the ecosystem to a condition between operating points or an original
trajectory requires that natural remnants be reunited into contiguous whole dynamic
areas. Where this is not possible due to existing or proposed intractable socio-physical
development, conditions should be attached to such development that assures gains to
minimum dynamic areas using natural remnants. Where fragmentation exists or will
increase, equal and opposite unification of the most highly productive natural remnants
should be required. Reconnecting fragments by: road closures; bridging; restoring
connectivity and networks; restoring grain and/or canopy appropriate to native species
may be appropriate and possible. Minimally, no development should occur without
permanent protection of equal and opposite spatial contributions to minimum dynamic
area. Transferring what cannot be saved in one location to another where it can be
saved contributes to cohesive ecosystems.

Where interventions to construct the socio-physical environment are to be
implemented, consideration of the biophysical environment can be included in the
design/planning process under four scenarios.
Scenario 1. Ian McHarg's 'ecological determinism' (McHarg and Steiner
1998:53) could be utilized to retain the original or pseudo-original state and minimize
future restorations. "In general, planning for natural process would select uplands,
coastal plains, and air-water corridors to remain relatively undeveloped; it would
confirm urbanization of the piedmont. It would protect surface water, and riparian
lands, exempt flood plains from development by land uses other than those unimpaired
by flooding or inseparable from waterfront locations, exclude development from
marshlands and ensure their role as major water storage areas, limit development on
aquifer resources and their recharge areas, protect prime farmland as present and
prospective resources of agricultural productivity and scenic beauty, ensure the erosion-
control function of forested steep slopes and ridges, and ensure their role, with forests
and woodlands, in the water economy, as a scenic-beauty and recreational potential
(McHarg and Steiner 1998:52-53)."
Scenario 2. Biotic losses will need to be reversed if normal evolutionary
processes are to be kept working within functioning ecological settings within the stated
parameters and in the face of socio-physical pressures. Beneficial exchanges between
biophysical and socio-physical environments may be possible if human interventions
into biotic systems were to integrate ecological restoration in the process of intervention
and if analysis of ecological effects of intervention could be used to generate the form of
ecologically friendly socio-physical environments.
Scenario 3. Because restoration should return natural disturbances cycles and
minimize human induced disturbances (Thorne 1993:34), integration of ecological
restoration with design process can take two paths. First, design can anticipate
ecological thresholds (Turner 1989:190) that can make land use and design decisions
that preserve them. Justus von Liebig's 'law of the minimum' illustrates the existence of
ecological thresholds. This law states that the greatest level of scarcity of a single
resource limits a population (Ricklefs 1996:428). In reality, limitations are more
complex, e.g. if the limiting factor is water, an individual may not survive with too little
water, however, it may also not survive with too much water as illustrated by Victor
Ernest Shelford's 'law of tolerance' (Allaby 1996:178). Neither Liebig's Law nor
Shelford's Law considers symbiotic relationships between species or competition
between species that can change minimum and maximum thresholds that resource
scarcity alone would predict. There is not enough known about symbiotic and
competitive relationships for all species involved to set ecological bottom lines to direct
design, however, single resource bottom lines can be used to guide design for most
native species. By consulting the work of taxonomists and natural historians, it is

possible to piece together a biological history of any site. Biophysical history can then be
used as a basis for restoration. Second, because land has a tendency to recover from
disturbances through succession (Thorne 1993:34), design can restore ecological
successions appropriate to native species into dynamic and evolving socio-physical
environments. Plant successions can be determined by referencing the historic record or
from observations or they can be predicted from the area climate patterns that set
limitations on them. Their inclusion into the design process is limited by space and
conflicting utilitarian and ethical goals. Spatial patterns are flexible to the degree that:
native species have adapted to particular perturbations; evolution adapts to changeable
conditions; and, if David Western is correct, the degree to which physiology is flexible
to environmental conditions (Western 1997). Patterns might include temporal and
disturbance adaptations.
Temporal Adaptations. For nocturnal species, socio-physical disturbances can be
limited to diurnal hours. For hibernating or torporal species, socio-physical disturbances
can be restricted to spring, summer, and autumn months.
Disturbance Adaptations. For species adapted to fire regimes, a lack of fire
constitutes a disturbance. It is therefore necessary for the socio-physical environment to
simulate natural fires by planned burns. Because natural fire events are stochastic,
planned burns will need to be random and allow plant successions at all stages. For
species adapted to flooding, restoring flood regimes is possible by released flows from
dams over short periods in historic volumes. This would restore soil fertility, fish
spawning, habitat creation, and resource availability.
Scenario 4. When components and functional relationships have already been
compromised by past decisions, then two possibilities exist. (1) Design can
incrementally restore or simulate original components to prepare for a possible future
restoration of functional relationships. (2) Isolated islands of non-native and inherently
unstable components and functional relationships can exist within a sea of native
components and functional relationships.
All four of the above scenarios are applicable to design and planning interventions. In
any scenario, specific conditions must be met to assure physical conditions that support
ecosystem integrity.
The National Research Council lists four considerations for determining the size of
restoration projects (Meffe et al. 1997:489): (1) large enough to minimize deleterious
effects of boundary conditions and events on internal dynamics; (2) a manageable size
that allows immediate adjustments to add control or eliminate disturbances; (3) large
enough so various effects can be measured to assess project success; and (4) achievable

with available economic and political commitment. Interventions and restorations
initiated by design and planning are subject to the same considerations. Because most
design and planning projects are small, the design disciplines directly consider
incremental units of large-scale ecology on individual projects. Working within the land-
unit scale and the landscape scale is the common milieu of design and planning. If
design and planning at any scale followed all ecological rules. Until we know all of the
rules, it is better to know the rules that apply to regional and global ecology and make
design and planning recommendations that meet them.
Projects are not necessarily scale dependent. Scale is a characteristic of the design or
planning project, however, it may also be limited by external factors beyond the control
of the design professional, e.g., a population's broader function as source or sink.
Scale is disturbance sensitive. Recovery from natural disturbances depends upon a
complex array of stochastic disturbance characteristics. Species that would need to
recover from these disturbances would need to do so regardless of project scale;
however, there may be limitations to stochastic disturbances. Tornado, severe freeze,
fire, and infestation disturbances may be expected to occur during specific seasons.
Disturbances may be tolerable where species have adapted to them. Socio-physical
disturbances that follow similar seasonal disturbances patterns would more likely be
tolerated by affected species and recoverable.
Large-scale projects may be more easily restored. Island biogeography theory
(MacArthur and Wilson) suggests: "A large site has a more complete and functional
infrastructure (a wider range of soils and exposures, more extensive and complete
hydrologic systems, and so forth), and can support more species. Similarly, large sites
have a greater capacity for self-repair than do small sites... (Meffe et al. 1997:491)"
Similarly, an intact or easily repairable abiotic system provides a solid foundation of
ecosystem components usable in restoration (Meffe et al. 1997:491). In addition,
restorations of hundreds to thousands of hectares are compatible with species
restorations or removals, and manipulation of ecosystem-scale processes, i.e. fire (Meffe
et al. 1997:491). Planning projects that consider larger regions thus would likely have
greater influence on implementation and help pull the restoration on its new trajectory.
Assuming that even small land-unit scale sites have and can continue to contribute to
natural process, restoring ecological successions to the socio-physical environment,
requires regulation of anthropogenic disturbances as follows:
1. All disturbances should be limited to dormant times of year whenever possible.
2. Large patch disruptions be minimized in area and time and include varying serai
stages in restoration as soon as practical.
3. Energy flow needs to be slowed.

a. Water flows should be restored to maintain minimum flows to maintain
native species and follow courses closely approximating original.
4. Canopy structure, where native, needs to be maintained at greater than 5%
(Forman 1995:460).
5. Socio-physical objects should be spatially arranged in the landscape to:
a. Meet ecological goals (Forman 1995:471).
b. Meet ecological thresholds of native species.
Restoration ecology should be first applied where the greatest gains are possible in the
shortest time, i.e. in marginally productive agricultural lands (Meffe et al. 1997:488).
Wetlands and riparian corridors also are a prime focus area because they are the basis
of many of the biotic processes and functions, and also contain a richer variety of life to
act as base material from which restoration can proceed.
Inappropriate Use of Restoration
"Take then thy bond, take thou thy pound of flesh;
But, in the cutting, if thou dost shed
One drop of...blood, thy lands and goods
Are, by the laws of Venice, confiscate
Unto the state of Venice."
William Shakespeare, The Merchant of Venice, Act IV, Scene 1
The concept of restoration remains controversial because it raises profound and
unresolved questions (Throop 1994:28). It is hard to disagree that humanity should
correct its mistakes, especially because our own existence depends on it, however, if
that promise of restoration encourages further thoughtless and destructive use of the
environment, restoration may further the demise of biophysical systems. In the above
passage, William Shakespeare illustrated that the act of doing what is legally right may
itself be wrong. Because it is not possible to restore exactly, questions remain whether
the semblance is of any value. If restoration produces something that needs constant
maintenance to work, the value of restoration may not be worthwhile. Is the restoration
natural or faked nature? If it is faked, does it have any value? If so, is it commensurate
with the economic costs that will be required for implementation? How are restorations
to be designed and evaluated in the face of incomplete science?
Ethical issues play key roles in restoration and cannot be resolved easily. For example:
the loss of a native species often creates opportunities for other species. If an
opportunistic species prospers in the created void, then is it right to remove or kill such
opportunists to allow restoration to succeed? When is it all right to accept that a new
trajectory is appropriate? What happens when all of the elements of a lost ecosystem

cannot be replaced because of human systems that will not permit it? By what rules are
"exotic species" defined? These ethical issues may arise in any human intervention into
biotic systems and will need to be resolved on a case-by-case basis with the help of
philosophers, scientists, and all stakeholders. The point of raising these questions is not
to resolve them, but to help define the restoration contexts when anthropogenic
systems cannot be eliminated or ignored?
A case study in Nairobi, Kenya illustrates more practical objections (Morell 1996). The
population of Nairobi at its first census in 1948 was 118,976. By the year 1999, the
population of 693 km2 Nairobi province grew to 2.14 million per internet source With the shape of Nariobi province extending in an
east/west direction, settlement of those people threatens to block traditional animal
migration routes in a north/south direction. Human/wildlife conflicts inevitably increase
due to proximity of people to park boundaries and attendant pollution, garbage, and
domestic livestock. According to David Western (Morell 1996), 80 percent of Kenyans
believe that wildlife is good for the country, while 95 percent of the landowners believe
it is not good for them. Because of similar problems in the western United States with
prairie dogs, bears, mountain lions, and wolves, I suspect that similar beliefs are held in
the United States because in both places, people pay a price for having to
accommodate wild animals. The voices of those who live closest with wildlife are often
missing or no compromise could be found when it was heard. Those who pay the price
usually find no benefit from the animals' presence, and finding a place for the
settlement of people usually does translate into some economic, social, and political
benefit. Because people's needs are immediate amid an uncertain future, short-term
gain usually takes precedence over long-term goals that will benefit unknown future
Lessons from the Literature
Proactive Approach is justified
Because of the strong relationship between restoration and sustainability, the more
prolific literature pertaining to sustainability can, in part, be applied to ecological
restorations. The concept of planning as used in the literature to refer to ecological
issues primarily deals with planning as used by biologists for ecosystem management.
However, the concept of planning is wider than that and can be used by planners of the
socio-physical environment. It does not seem possible to separate 'ecosystem-based
planning' from 'planning to maintain ecosystem integrity'; therefore the literature is
applicable to both.

C.S. Holling has outlined five points of view concerning ecological stability and capacity
for change (Gunderson et al. 1995:14-15). They are: (1) nature cornucopian view
where exponential growth will always provide resources because human ingenuity
always invents substitutes; (2) nature anarchic view where decrease inevitably follows
increase and humanity is incapable of dealing with unleashed technology; (3) nature
balanced view based on a recognition of looming ecological turmoil that must achieve a
sustainable plateau; (4) nature resilient view that ecological cycles are nested and
organized by discontinuous events and processes leading to periods of exponential
change, growing stasis or brittleness, readjustment or collapse, resulting in
reorganization or renewal; and (5) nature evolving view where nature is evolutionary
and adaptive. If each of these has elements of truth, then the only intervention strategy
that fits all views is one that is conservative. Strategies such as resource management
and development, ecosystem restoration, and sustainable development are conservative
approaches to problems of population growth and technology. Because ecological
problems are a topic of concern to everyone it is appropriate that those who initiate
changes that can cause such problems are also charged with dealing with them.
The opportunity for dealing with ecological problems is based on two principles. In the
first principle, human cultural, religious, social, and economic activities almost always
interact with natural processes to produce the actual patterns, movements, and changes
observed over time (Forman 1995:15). "Traditional Chinese philosophy focuses on the
harmonious relationship among Tian (heaven or universe), Di (earth or resource), and
Ren (people or society) (Forman 1995:15)." Yin and Yang doctrine emphasizes the
duality of natural forces present in this relationship, and Feng-shui expresses the spatial
qualities of this relationship. In the second principle, all processes follow processes of
birth, growth, death, and renewal (Gunderson et al. 1995:25). Change is thus inherent
in the socio-physical environment and provides opportunities to redirect its form to
protect all natural communities to their historic range of variability and to restore
minimum viable populations of native species across their native ranges. Because
biodiversity favors some portions of the landscape more than others, it is possible to
define ecologically sensitive spatial contexts that can influence design and planning
decisions. From the design and planning perspective, ecosystem restoration is
concerned with assuring physical conditions that are essential to natural range of
Biological Limits Set the Stage
The first spatial context is defined by a predator-prey system that is itself checked by
five factors: predator inefficiency; density-dependent limitations; alternative predator
food sources; refuges from predation; and reduced time lags in predator population

response to changes in abundance (Ricklefs 1996:467). Because these factors lead to
multiple stable states in predator-prey relationships, it is unlikely that design would
substantially influence predator-prey relationships except by restoration of keystone,
rare, and endemic predator species where they have been removed. Restoration of
species will allow functional ecological settings to re-establish themselves with the
addition of predator-prey relationships. Because restored species should have an
ecological advantage by utilizing an unstable ecological state, small numbers of restored
individuals should quickly achieve parity and enter into one of the multiple stable states.
Wolf restoration to Yellowstone National Park, for example, appears to be achieving
dynamic equilibrium and resumption of their role in a functional ecological setting
(Bangs et al. 1998; Klein 1999). According to Donald Scherer, it is not necessary to
restore particular native species because natural processes that species effect can be
accomplished by restoring species of the biological families to historic niches (Throop
2000:175). It is possible to determine historic presence of native species in most areas
by consulting the historic record.
Inadequacy of Science
Because ecosystems heal themselves if the basic elements of the ecosystem exist, the
question arises as to what basic elements need to exist to make that healing possible.
Because we do not understand the entire workings of ecosystems, essential elements
are unknown. Science should be relied upon to reveal the elements; however, the
dynamic character of ecosystems eludes and confounds nomological analysis.
Therefore, much of ecosystem dynamics must be inferred making it impossible to
restore all of the details. It may, however, be possible to restore general processes and
functions. If sufficient natural process and function can be closely approximated from
data that science can provide, then it is possible to design and plan to affect a condition
of self-healing and a return to autonomic ecosystem conditions.
It will always be expedient to wait for science to develop conclusive evidence that a
problem needs to be solved and to wait for science to develop strategies for doing so.
However, because the stakes are so high, waiting will never be prudent. Science at best
can provide answers and tools for solving important problems as this. Philosophy tells us
what we should do. Rather than argue about ethical conflicts and whether we should
accept moral responsibilities that philosophy might impose, in matters of life and death
we are obliged to consider worst-case scenarios and possible actions that might remove
risks. Dealing with this problem has no negative outcomes and has the potential to
enlarge our perception of the biosphere that we can neither avoid or dominate and
expand our concept of appropriate respect for all life.

"/ wonder if the ground has anything to say ? I wonder if the ground is listening to what is
said?" Young Chief, of the Cayuses tribe (upon signing over their lands to the US.
Government, in 1855) (Abram 1997:181).
The purpose of protecting ecosystems is to acknowledge an intrinsic value in all living
things and confer an appropriate respect for all life, and/or to sustain the conditions that
provide resources and services that support all life including humanity. In both
circumstances, the normative condition must be physical states in which minimum
requirements exist that are required to sustain life. It is valuable to continue to protect
ecosystems and their components by preserving remnants of unique landscapes that
support endemic species, and by preserving remnant landscapes that support the widest
variety of remaining species. However, any protective measures must have minimum
ecological thresholds as the normative condition and a strategy for dealing with
inevitable future losses due to human population growth and inevitable socio-physical
development or it achieves its goal only by chance.
Ecological thresholds are set by the physical conditions of site and adaptations that have
been made to those conditions over time. In effect, they are what the ground has to
say. If ecological thresholds were known and native ecosystems were still intact, it
would be possible to respond by designing and planning the socio-physical environment
to meet minimum conditions and/or preserve native ecosystems. Because ecological
thresholds are not well defined, it is necessary to reconstruct the historically dynamic
condition, i.e., a condition where an ecosystem retains its integrity and functions
autonomically. Design and planning recommendations can then be made to restore,
preserve, and otherwise assure that the normative condition is in place. A procedure
that would provide the design disciplines an alternative to further weakening ecosystem
resiliency rests upon two essential attributes: adequate species composition and
abundance; and the physical conditions necessary for their survival (Clewell et al.
2000:1). This procedure would set in place the opportunities for nature to reestablish
functional ecosystems, their maturation, and adaptation to changing natural conditions.
This chapter describes a procedure for determining: limits of adequate composition and
abundance; which species are subjects of concern; and physical conditions required to

sustain ecosystems. Such preconditions can guide interventions into natural systems so
that ecosystem function and process are assured.
Protections that could have the most comprehensive effect on ecosystem process and
function would be proactive, address prior losses and fragility of remnant ecosystems,
apply to all ecosystems, provide the most temporal and spatial flexibility for changing
plant and animal communities, and be permanent and enforceable. These
preconditions necessitate that a strategy for assuring natural process and function
address how people use the land.
Human needs are not forgotten in this procedure, but are the subject of socio-physical
development and will be addressed during design and planning. Because biophysical
conditions required for natural process and function are inflexible and cannot negotiate
or compromise, appropriate design and planning responses require flexible socio-
physical environments and institutions.
How the Procedure Was Developed
Because human need or desire and biophysical environments are not always
compatible, an appropriate procedure should identify spatial and temporal spaces that:
address essential resources for native species and humanity; define the limitations of
each; and addresses inevitable interfaces between them. Design and planning
recommendations can then be made to preserve and/or restore resources that are
required for survival of native species, locate socio-physical development in areas that
are less valuable to native species and to reconfigure the landscape to achieve
contiguous habitat.
Adequate Species Composition and Abundance
Every species must retain populations large enough to maintain genetic variability and
be able to sustain losses due to any cause. Because most species also rely upon services
and resources that other species provide, composition of species assemblages must
include all dependencies. Because each species and species assemblage require specific
resources that are limited by time and space, species composition and abundance can
be translated into physical and temporal space. These physical dimensions provide
designers and planners with criteria usable for creation of the socio-physical
Design and planning could accommodate adequate species composition and
abundance along with physical conditions that support them if: key ecosystem

requirements are known; the probability of losses due to all disturbances can be
predicted; and opportunities exist to avoid or recover from losses. In the absence of the
ability to completely know requirements or disturbance effects from stochastic events, it
is necessary to plan for ecosystem requirements at wide temporal and spatial scales, i.e.:
1. Ecological plans should be compiled based on ecosystem inventories and global,
regional, landscape, and local ecosystem processes and functions to determine
relationships and how resources at each scale contribute to life at other scales.
2. Minimum dynamic areas should be identified, configured, and restored to
contiguous and complete habitats without human disruptions to maintain
maximum opportunities for the most biodiversity.
3. Ecological redundancies should be planned to compensate for our lack of
knowledge about ecological thresholds and ecosystem behavior.
These characteristics are the outcome of the procedure developed below and
applicable to all ecosystems and all socio-physical interventions and environments.
Requirements of Native Species
Composition. The first requirement for a workable procedure to guide design and
planning is to know the composition of native species that physical conditions must
support. Native species are the focus because they were part of an autonomic system
that operated free from human influences. Because it is not possible to inventory lost
species, and extant species usually are present to take advantage of resources in altered
ecosystems and are therefore different from native species, native species composition
must be determined by other means. Possible prior existence of specific flora and fauna
is dependent upon climate and soils that supported them, or presence of a species or
assemblage reveals site characteristics. Therefore, once historic species presence is
known, historic physical characteristics can be inferred and guide restorations. Recent
historic range of variability for any location can be pieced together in the following
1. It is possible to determine the recent historic presence of biota by observation
and study of climate, landform, and soils based upon map interpretation,
historic records, testing, and on-site observation.
2. It is possible to determine the recent historic presence of biota from the historic
record in the form of zoological collections and logs, scientific expeditions and
explorations, and anecdotes.
3. Recent historic presence of biota can be known if soils are known. Because soils
are a product of climate and landform and feedback from biota, the biota that
certain soils support can be compared to biota supported by similar soils.

4. If some of the biota is known, related biota that share some dependencies can
also be known.
Because design and planning has only an indirect affect upon species composition, the
design disciplines need to know native species to preserve or restore physical
characteristics that they can directly influence.
Data about biotic components that make up genetic diversity and demographic security
are essential, but it is not necessary or possible to know everything about each
component. Each piece of data can be used to complete a picture of a once autonomic
ecosystem of historic characteristics and evolutionary directions. These historic
trajectories should be unmistakable if the data is correct, and if the data is not correct,
trajectories will not match. The objective is to achieve a complete picture of conditions
that no longer exist. This is possible by using several data. Because each ecosystem is
the function of several components, the use of any set of components should inform of
a common historic trajectory. Once the historic trajectory is known, they can be
translated into physical characteristics of the ecosystem that can be restored and/or
protected to support that trajectory.
The distribution of any species is limited by two factors: (1) vagility, i.e., whether species
could get to any particular area; and (2) ecesis, i.e, once species got there, whether they
could "make a living" (David M. Armstrong, personal communication). Both factors can
be translated to physical characteristics usable by the design disciplines. Vagility requires
connectivity between physical resources and sufficient population to recolonize
disturbed areas without losing genetic variation, and ecesis requires physical space for
primary production of resources required to support species. It is always preferable to
determine range of any species from field studies or data derived from field studies.
Because that is not always possible, characteristics of the landscape that influence range
and the possibility of a species presence can be utilized as criteria to evaluate whether
any trajectory is possible. The following formulas illustrate this point.
State of ecosystem = / (climate, organisms available to colonize the site,
topographic relief, soil parent material, and time since last disturbance),
sometimes known as the 'clorpt model'.
e = / (cl,o,r,p,t...) (Baydack et al. 1999:73)
Soil and biota =/ (climate and landform) (Bailey 1995:39)
These formulas are not intended to explain evolution of species. They are important to
design and planning because in dynamic ecosystems, ecosystem behavior should be
within a normal trajectory as long as factors that control ecosystem behavior retain

physical characteristics that are within historic range of variability. Physical conditions
that control ecosystem behavior can be determined and expose the physical conditions
that assure ecosystem integrity. In native habitat, an inventory of native biota can be
used to directly determine extent of minimum dynamic. In non-native habitat and
where the biota is unknown, a close approximation of native assemblages can be
determined from the above relationships. This approximation is derived from known
physical conditions that would normally control ecosystem behavior. Therefore, where
climate and landform retain historic characteristics and configurations, ecological
restorations from the designers and planners perspective are a matter of restoring
physical conditions that native plants and animals would need to survive.
Abundance. Minimum effective areas support minimum populations. The
survival of any native species depends upon range availability with sufficient resources
to support minimum effective populations distributed over the landscape in sufficient
numbers separated at distances beyond any stochastic events. Sufficient genetic
material must remain in large enough populations to act as source for repopulating
disturbed areas. Minimum viable population (MVP) size is variable for all species and is
not consistent for any one species all of the time (Ballou and Foose 1996:276).
The population of each species that must be maintained in each geographic area to
retain genetic variability is dependent upon the remaining number of genetically
effective individuals, generation length, and the number of years that preservation is
required. In this case, the normative condition should be 100% of species are to be
preserved forever. Because detailed data of genetic structure and evolutionary history
do not exist (Noss et al. 1997:98), estimates of population viability should be
conservative. About 5000 genetically effective individuals of a population appear to
have some abililty for long-term persistence or about 10,000 to 20,000 individuals
(Noss et al. 1997:94-98).
Required range generally can be determined because range is a function of body mass
and the biomass that any particular area can produce. Because body mass and quality
of range is inconsistent, area requirements for range will also vary. Minimum effective
area for any complete assemblage is roughly equivalent to the range appropriate to the
largest herbivore, carnivore, and any keystone species because dependent species or
species lower on the food pyramid are food for the top carnivore and are contained
within its range.
Body masses and home ranges are available from some scientific sources. However,
they are highly variable. The mountain lion, for example, ranges from 35Kg-100Kg
(Fitzgerald et al. 1994) and requires a range of 10,000-30,OOOha at a density of 0.0002-
0.0004 per hectare (Currier 1983). Where density can be determined, the job of finding
home ranges can be simplified. A density of 0.0002 individuals per hectare means that

to accommodate 1 mountain lion requires 1/0.0002 = 5000 ha. A density of 0.0004
would require a range of 1/0.0004 = 2500 ha. Because of the discrepancy, range should
be verified using other sources. Haretad and Bunnell (1979:392) note that Felis
concolor has a mean body weight of 67kg and have a home range of 29,733 ha. This
figure agrees with the previous upper figure. Assuming it is possible to maintain
minimum viable populations of 20,000 individuals by maintaining three connected
populations of 10,000 individuals, 5000 ha X 10,000 = 50,000,000 ha each, three
areas 707Km square (438 miles square), will be required to support a minimum viable
population of Mountain lions. Home range requirements can also be determined by
Range = 13.2M 136 (Calder 1996:29)
Using the same 67Kg weight, 13.2M 136=4018 ha/lion. At 4018 X 10,000 individuals =
40.180.000 ha required for a minimum viable population of mountain lions. Three of
these areas located separately and connected would be required to assure a 20,000
minimum effective population. Each area would be approximately 634Km square (393
miles square). Because 4018 ha is 80% of 5000 ha, and habitat will in most instances be
irregular, varying sizes between the two extremes may be acceptable. However,
because of the uncertainties in any natural system, it is safer to use the 5000 ha figure.
For comparison, wolves are included below. This theoretical comparison is used to
illustrate that space required for gray wolves would include all species that would be
part of the gray wolf diet and all flora and fauna that support those species.
Range = 13.2M 136 (Calder 1996:29)
Cray wolf Canis lupus M = 18Kg-80Kg or 37.3Kgmean
13.2M 136=1812 ha/wolf
At 1812ha/wolf, a 10,000 population would require 18,120,000 ha. If all habitats are
connected to allow movement between populations, 10,000 wolves in each of two
populations would be sufficient to retain minimum effective populations if there were
20.000 individuals remaining after any stochastic event. This means that there would
need to be at least three gray wolf populations of 10,000 or more widely distributed
beyond the influence of any single stochastic event. 18,120,000 ha required for each
population translates to an area of 426km square (264 miles square) or about 70% of
the area of Colorado.
Verification of the above calculations can be made using different literature. According
to (Payne and Bryant 1994:34) Range Cray WOif = 0.022W 130
Weighty =37,300g mean 0.022W 130= 19,304 ha

If an estimated 11 individual pack members share this range, 19304/11 = 1755 ha
would be required for each individual. This figure compares closely with the 1812 ha
derived from the above calculation.
These similarities can be expected because each of the formulae for gray wolf was
derived from the same literature source. Therefore, it is worthwhile to see how well
these figures compare with that literature (Harestad and Bunnell 1979:391). That study
was based upon 9 previous studies that yielded a sample size of 30 individuals.
Canis lupus Massmean= 37,422 grams Rangemean = 20,276.88 ha
Because wolves are territorial, mean range divided by mean pack size should give an
approximate range requirement per wolf.
20,276.88 ha per pack/11 wolves per pack = 1843 ha per wolf
All three of the above figures are very close and can be expected to be approximately
correct. However, they can be verified by comparing to recent field studies.
Data on gray wolves in Yellowstone National Park reveal that 11 packs of Gray wolves
totaling 115 wolves occupy the 898,321.11 ha area of Yellowstone NP. This translates
to 7811 ha/individual. If the 1843 ha/wolf figure is correct, it appears that Yellowstone
wolf recovery program is not yet complete and we should expect to see a total of 497
wolves in Yellowstone National Park using Harestad and Bunnel's figures (1979).
Because Yellowstone NP is among the highest quality natural environments in the
conterminous United States, we should expect to see a larger number than the mean.
The above calculations present a problem because the numbers of wolves required
exists only in the remotest parts of Alaska and Canada and would be impractical to
restore the historic range of variability for wolves. It would put a burden not only on the
human population that presently occupies former wolf habitat, but it would most
certainly be a burden to wolves. This conflict is further illustrated in case study number
3 in Chapter 4 that indicates the broad range that wolves would have over the
landscape leaving little space for humanity. However, our socio-physical development
strategies must retain the areas calculated above in some regions of this continent and
perhaps other regions of the world and plan the remainder of the region to contribute
to these remote wolf habitats. The inability to accommodate wolves means that some
management of natural areas to compensate for the inability of wolves to fulfill their
natural roles is necessary, but the goal should be to minimize the need for human
management of natural systems wherever and whenever possible.
Minimum dynamic areas support natural recovery. Once any minimum effective area is
known, the minimum dynamic area can be determined because no fewer than two

minimum effective areas must exist if they are sufficiently distant from each other that
no stochastic event or set of events is large enough to disturb both populations at the
same time. Simultaneously they must be proximate enough to each other to allow
colonization after disturbance. According to the Theory of Island Biogeography (Ricklefs
1996:610), colonization is lower as distance between populations increase. Populations
therefore should be proximate enough to allow colonization after any population is
erased by any stochastic event. Because the extent of stochastic events is not
predictable, there should be more surviving populations beyond stochastic events than
less. Richard Forman (1995) calls for 2 to 5 minimum effective populations depending
upon whether the range of the species is beyond the largest probable stochastic event
and genetic variability is maintained. Large carnivores, for example, may easily survive
in fewer minimum dynamic areas because their range is far larger than any single
probable stochastic event.
A required area of 426km square (264 miles square) to the design disciplines means:
1. Because habitats are products of nature and follow natural borders rather than
economic or political boundaries, the design disciplines must make
recommendations that are related to ecosystem process and function in
addition to relating to property lines.
2. Ranges are often so large that few areas exist that are cohesive and unoccupied
or otherwise undisturbed by the built environment. Therefore, the design
disciplines must make recommendations that make the ranges function as if
they are still cohesive and undisturbed.
3. The design disciplines must plan the socio-physical environment to retain or
restore minimum dynamic areas in sufficient numbers and distributions to
accommodate minimum viable populations of native species connected by
multiple wide corridors.
4. Design processes must always evaluate project sites and make
recommendations that enable the project site to contribute to a larger
ecosystem. The design disciplines must take care to minimize fragmentation of
large areas and to reunite fragmented areas into large cohesive land habitat,
because most land areas subject to design and planning projects are much
smaller than these requirements.
5. The design disciplines must evaluate quality of alternative project sites as part of
a larger ecosystem and place socio-physical development in relatively lower
quality habitat.
Physical Conditions. The normative condition for any subject area provides the
designer or planner with a general understanding of the important relationships,
essential ecological requirements, and serves as a context for the compilation and
evaluation of natural process and function prior to extensive human interventions, i.e.:

1. Physical description The subject area should be described with a written
description and/or graphic representation, such as maps, drawings, or aerial
a. Location Provide a legal description of the subject area that includes
lot number(s) and name of subdivision(s) where applicable, and
governmental administrations, e.g., town/city, county, and state. Include
boundary coordinates and physical size of subject area in hectares.
Hectares is chosen because scientific literature is generally in metric
measure and they are more convenient to use than British measure.
b. Elevation Determine the range of elevation above mean sea level
(AMSL) across the study area.
c. Climate/Eco-climate zone Identify the climatic zone(s) of the region or
site including: annual precipitation; annual average temperature and
day/night variation; and characteristics of wind or other climatic
influences. Each land area is identified with an eco-climatic zone
designation that may be useful in site analysis (Bailey 1995).
d. Ecoregion Each land area of the world is identifiable by ecoregion
(Bailey 1995). These identifiers form the basis for broad understanding
of regional ecology as the designer/planner becomes more experienced.
2. Soil type Identify soil type using standard designations. The most accurate
method at the site level may be determined in field studies by geotechnical
engineers. For landscapes, county level soil surveys provide adequate soil data.
Identify and document soil horizons and provide a verbal description.
3. Vegetation Compile a physical description of vegetation type across the
region. Once the associated vegetation is understood, this characterization
provides simplified referencing for discussion and writing. See (Bailey 1995:65)
4. Potential primary production and/or Biomass- Each ecosystem is capable of a
limited amount of plant production. Although these figures are approximate,
they provide a general idea of the quantity of living matter that can be
supported in any identified area. See (Bailey 1995:47). Biomass is a result of
primary production.
5. Original drainage Identify characteristics of the original drainage patterns.
They are key to ecosystem structure. If topography is not already included in
item 1 above, it should be added. Draw lines on the topography to indicate all
drainage patterns.
6. Geographic characteristics Identify all atypical geographic characteristics in the
study area and look for plant and animal life that is atypical of this area. Each of
these atypical areas may embody microclimates and soils that support endemic
or obligate species.
7. Natural disturbances Identify all natural disturbances that have played or do
play a role in shaping the ecosystem in the subject area.

8. Anthropogenic disturbances Identify all human interventions that have played
or do play a role in shaping the existing environment in the subject area.
9. Historic range of variability The keystone of this procedure rests on the theory
of HRV. This is a useful, but theoretical model that can guide design and
planning by defining optimum natural physical conditions. Ecological integrity is
based upon biological threshold of native systems if maturation of natural
process and adaptation to natural change were to continue. Therefore, it is
necessary to know what existed prior to change by non-indigenous people and
the extent of their influence to native conditions. Determination of HRV before
non-indigenous people assumes that the greatest anthropogenic change
occurred after settlement by non-indigenous people and that occupation by
indigenous people was sustainable. Both assumptions could be incorrect, but
biotic thresholds at this juncture are probably as accurate as can be determined.
Once native species are known, their minimum biotic thresholds can be
determined based upon their individual physiology, behavior, and morphology.
Once these are translated into physical site characteristics, the design disciplines
can make certain that such characteristics that support a species physiology,
behavior, and morphology are present.
Most native and non-native abiotic and biotic characteristics of an area can be
determined by survey of the historic record. Because the presence and distribution of
any species is a function of climate and landform that can be traced through time, it is
possible to determine generally what species assemblages could have existed in any
ecosystem at any particular time. In addition, the known presence of one species can
inform on the assemblage of species that a species was a known part. Because climate
generally establishes how much primary production and area can support, the known
body masses of individual native animals can be used to determine how much land
area is required to support any native species. Determining the minimum size of an
area that will support an assemblage of native species is simplified in this procedure
because of the second law of thermodynamics. The concentration of energy as it
proceeds up the food chain necessitates that all species within an ecosystem be
included within the range of the largest carnivore. Additionally, all species that are
dependent upon a keystone species to provide resources for their existence should be
included in the range of keystone species. Therefore, by inference, minimum dynamic
areas of any assemblage can be determined by knowing body masses of the largest
known native carnivore and keystone species that existed in any particular area at a
time when distribution was not influenced by human interventions. The close
dependencies of biophysical components essentially make them functions of one
Spaces. Once biophysical target conditions are established, the design disciplines
can analyze project sites at any scale to piece together biophysical components that can

be directed to fulfill target conditions and establish project plans that assure their
restoration. Project site analysis should take two forms. Foremost consideration should
be given to historic spatial and temporal scales as they relate to native biotic systems,
then to how immediate human needs can be facilitated within that biotic framework.
The following steps identify a process of project site analysis that serves biophysical
goals and guides ecological restorations.
1. Identify one, two, or three species that play the most important roles in
structuring the ecosystem and their effects on potential loss.
2. Identify all species in the area that are obligate and endemic to the area and
their minimum effective areas.
3. Identify a spectrum of biodiversity with sites that retain native biodiversity at all
levels of biological organization (Redford and Richter 1999:1250).
4. Identify the extent of the whole system that extant native biodiversity is a part.
5. Identify indispensable and favorable spatial patterns (Forman and Collinge
a. Two to five large patches of natural vegetation that meet the minimum
effective area for the species with the largest home range (Forman and
Collinge 1996:539).
b. Riparian corridors freely accessible and open to movement along their
entire length.
c. Connectivity by wide corridors between large patches (Forman and
Collinge 1996:541).
d. Vegetation grain/mesh across the matrix to fit native species (those
identified in item 3 above) movement tolerances (Forman
1995:490,268). Native or nearly native ecosystems should not be built
on, but may require management to remain native.
e. Identify land areas that can be eliminated with little ecological loss.
These include: soils that are low in productivity and provide little value
to the maintenance of the ecosystem; areas where a green matrix
surrounds brown patches the brown patches and any green lobes and
corners extending into the brown patch may be occupied by socio-
physical development (Forman and Collinge 1996:555); medium sized
patches (Forman and Collinge 1996:556); and major lobes of large
patches (Forman and Collinge 1996:556).
f. Identify patterns of disturbance spread and faunal movement responses
to disturbance (Forman and Collinge 1996:538). Although there are
many different patterns that vary depending upon location, the
important points are: minimum effective area (MEA), minimum dynamic
area (MDA) must be much larger than disturbance area; the possibility
of every stochastic natural disturbance must remain; no socio-physical
development should be placed in areas that exhibit moderate to high

frequency of disturbance unless they are immune to such disturbances;
and all disturbances should be recoverable by normal succession and
serai stages.
6. Identify extant and/or proposed socio-physical disturbances to ecological
thresholds including kind and extent of disturbance. Extent of disturbance
should be shown on large-scale aerial photo and on soil and topographic maps.
Relationships with watershed should be identified and noted along with other
contributing aspects of surrounding landscape.
7. Identify conflicting land-use between biophysical and socio-physical needs.
8. Identify the kind of ecosystem to be restored and type of restoration project
(Clewell et al. 2000:2). Type of restoration could be:
a. Repair of damaged ecosystem.
b. Creation of a same kind of new ecosystem to replace lost ecosystem.
c. Creation of another kind of regional ecosystem to replace lost
d. Creation of a replacement ecosystem where an altered environment can
no longer support original ecosystem.
e. Creation of a replacement ecosystem due to altered ecosystem and lost
reference to original ecosystem.
9. Document physical site conditions in need of repair (Clewell et al. 2000:3).
a. Climate Because climate acts as the primary control for ecosystem
distribution (Bailey 1995:39), restoration is keyed to local climate
patterns by way of defining ecosystem boundaries. Where climate
patterns have changed, there is no amount of ecological restoration that
can recover historic ranges of variability. This is what makes global
climate change so important.
b. Hydrologic cycle
c. Removal of anthropogenic structures to reestablish a more natural
hydrologic regime that may include restoring porosity to surfaces.
d. Soil improvements
i. Decompaction
ii. Microorganism replacement
iii. Increased organic content
iv. Increased nutrient content.
Once known, historical range of variability for bioregion, landscape, or land unit can be
restored by manipulation of components by the design disciplines. It is possible to
restore the historic range of variability of the hydrologic cycle and achieve restoration of
other components because the hydrologic cycle is a function of climate. If climate
patterns have not changed appreciably since the time of European settlement, then
climate patterns can be compared to landform and reasonable determinations can be
made concerning hydrologic characteristics that can be manipulated by planners. Once

the hydrologic cycle is restored, it is possible that biotic successions that resemble
natural trajectories can resume. Available knowledge dictates whether restoration is
approached from details or systems. Known whole systems and assemblages across
spatial and temporal scales not subject to interventions by non-indigenous people will
be the model for restorations as follows:
1. Restoration requires the existence of native species in historic trajectories.
Where species no longer exist, it may be possible to restore native families to
which extinct species belonged to historic trajectories. The complete historic
range of variability is necessary for restoration, however, their return is not a
matter of replanting and release of animals captured elsewhere. If restoration is
possible, habitat must be recovered and supported by design and planning
recommendations at all scales. Capture and release is probably not feasible
because if it were ethically acceptable (not the subject of this dissertation),
release would require known habitat vacancies with survival conditions known
and present. The best that is possible for most species is to restore the
opportunity for vagility and ecesis that could attract native assemblages over
time. However, because keystone species may provide many of those
opportunities, restoration would have to rely upon keystone species finding
opportunities in restored habitat first. To speed the process of repatriation, the
attempted release of keystone species in restored habitat by biologists may be
2. The primary character of the ecosystem is that which provides all native species
with opportunities for making a living. Any change to the natural matrix changes
opportunities that favor an assemblage of species different from the native
assemblage and often lacks keystone, mutualistic, and symbiotic species. The
natural matrix must remain after socio-physical development. Where socio-
physical development alters the natural matrix, developed areas must remain
separate from the natural matrix. The size of the natural matrix can be reduced
to no less than the land area required to support minimum effective and viable
populations of native species separated in distance by probabilities for stochastic
events. Where minimum dynamic areas may have already been changed by
anthropogenic disturbances, restoration of the native matrix must be distributed
across the landscape so that at least two minimum effective populations are
beyond the possibility of any stochastic event. Because all smaller ranging
species of a native assemblage live within the range of the widest-ranging
primary and secondary consumers, the minimum size of required natural matrix
is based upon the largest ranging keystone species and carnivores.
3. Keystone species make it possible for other species to survive because their
disturbance of the environment creates opportunities that would not otherwise
exist. Across the grasslands of the Great Plains, bison were a keystone species

that is now absent. If restoration is to be complete without human management,
bison or the role bison played must be restored to benefit dependent species.
4. All species and habitat of endemic species must be maintained. If endemic
species have been lost, they cannot be restored. Therefore restoration will have
to restore families of all lost endemic species and their habitat.
All species that rely upon a particular portion of the landscape at some time of year
must be able to utilize that particular area to survive. If the area exists in its natural
condition, it must remain so. If the area has been disturbed so it no longer supports
obligate species, the species can survive only if minimum dynamic area exists
elsewhere. If minimum areas no longer exist, obligate species may be in the process of
collapsing or lost. If remnant species exist, immediate restoration of the obligate habitat
is essential.
Temporal Spaces. Although the effects of compromised ecosystems upon
humanity is debatable, the potential risk to human survival and other life dictates that
conditions that support natural process and function receive high consideration.
Therefore a strategy for change must also be included in this procedure. A strategy for
change must bring the socio-physical environment into compliance with conditions that
support natural process and function and restore the biophysical environment to a
condition of self-maintenance. Assuming that present levels of perturbation to
ecosystems pose risks to humanity that will increase under expanding socio-physical
development, the appropriate human response is to restore physical characteristics that
support natural ecosystems to a condition where all native assemblages are self-
sustaining. Because ecosystems are too complex to comprehend enough to manage,
and none are fully free from human influence, ecosystem restoration must be based
upon conditions that existed when ecosystems maintained themselves. Because self-
maintaining ecosystems did exist prior to interventions by non-indigenous people,
ecosystem restorations are most accurate when guided by natural historic variability.
Therefore, all changes to the socio-physical environment can be directed to fulfill
conditions that meet biophysical and socio-physical goals.
Assuming that an environmental catastrophe has not already been triggered, political,
social, and economic considerations will make it necessary to ease into ecological
restoration. Gradual change of socio-physical environments to meet ecological
thresholds is compatible with natural systems because gradual change mimics natural
recovery patterns of succession. Actual patterns of socio-physical change may change
depending upon type of ecosystem. Some forests recover in four serai stages (Ricklefs
1996:522), whereas grassland grassland will usually recover as soon as moisture is
present and temperature permits growth from existing root structure. Where
disturbance extends to the root structure, reseeding and/or replanting from seed derived
from native remnant stands may be required. Integrating natural recovery patterns into
design and planning will minimize long-term biotic losses and enable creation of the

socio-physical environment without loss of ecosystem integrity. It will also create socio-
physical environments that conform to local environmental characteristics. If every new
socio-physical intervention restored more than was lost, the natural environment should
recover natural resilience. This should be possible because socio-physical environments
are not static, but change over time through decay and renewal. The physical extent of
the restored target condition can be determined as explained in the section on
"determining historic range of variability" that follows. Formulae (Payne and Bryant
1994:34; Calder 1996:29) show that species with individuals of small body mass can
survive in many small remnant ecosystems with appropriate resources as long as they
are connected to other areas populated by the same species that are far enough away
to avoid all populations being lost to a single large or series of closely spaced stochastic
events. The formulae do not show that species specific behaviors and vulnerability to
predation or competition by non-native species often require that even small animals
require large cohesive habitats. Large animals of grazing and carnivorous species require
large amounts of land area connected to other large areas. The same formulae applied
to larger mammals indicate that large grazing and carnivorous species require extremely
large habitats and connected with other habitat. Because the range of large grazing and
large carnivores is hundreds of thousands of hectares for each population and these too
must be connected, providing physical assurances necessitates large preserves exist with
ample connectivity. However, because all remnant ecosystems provide resources for
the larger carnivores, small remnants need to be integrated with large contiguous
Compatible Biophysical and Socio-Physical Environments.
Connectivity Promotes Recovery. Minimum effective populations distributed
across a landscape without any means of interaction would be ineffectual to the
creation of a viable population. Colonization must be possible and genetic variation
must be able to be distributed between sub-populations. Maintaining connectivity
between populations is essential to the existence of any native assemblage of plants and
Species Rely Upon Primary Production. Native environments must have the
ability to produce renewable resources before they can support native species. Because
primary production is dependent upon basic geophysical characteristics of the soil and
climate, restoring soil and hydrology is an appropriate starting place. Based upon the
first two laws of thermodynamics, all ecosystem organization can be reduced to energy
flow (Odum 1993). To the design disciplines, maintaining energy flow translates to
assuring connectivity.
Hydrology. The water holding capacity of soils prior to disturbance sets up
conditions that support native species. Water holding capacity should be tested prior to
disturbance and restoration should match native conditions. When required

compaction can be reduced, litter added to the soil and adding earthworm as
appropriate can create pore space.
Microclimate. The presence of native species is dependent upon a spectrum of
microclimates in any region. Those microclimates provided the opportunities for
biodiversity to move in and survive. Disturbances of any kind disturb microclimates and
the flora and fauna that inhabit an area. Ecosystems recover where disturbances do not
reduce adequate species composition and abundance or conditions required for them
to survive. Extensive disturbances transform nutrient dynamics (Parker and Pickett
1997:22) and change normal successions that sustain native ecology. Historic energy
cycles and flows must be maintained along with nitrogen cycling and species
Soils. Soil is the medium for energy flow to plants. Water and nutrients in the
soil contribute to soil fertility that in turn supports animal life. Soil moisture aids
decomposition of plant and animal life that contributes to soil nutrients. Soils are easily
damaged by erosion, compaction, moisture depletion, and nutrient depletion, but they
can be restored if the ecosystem has not lost resiliency and shifted to a different
ecology. Water and nutrient replacement will restore basic soil characteristics. Seed
drilling, hydroseeding, or planting nurse plants to support native species and stabilize
soil can restore and favor native species. Soil must match native conditions so
succession can follow historic trajectories. Ripping and scarification can relieve soil
compaction, and further soil stabilization can be accomplished by amending mica and
fines in the soil (Bradshaw 1997:44).
Soil chemistry. Disruption of the phosphorus cycle can be determined by soil
analysis and restored with one application of sewage sludge (Bradshaw 1997:47).
Potassium cycle is also necessary, but is usually not disrupted by socio-physical
disturbances and requires no supplements (Bradshaw 1997:48). The nitrogen cycle
must be maintained, but because skeletal soil usually does not have nitrogen, it must be
supplemented (Bradshaw 1997:49). Nitrogen can be added by applying slow-release
mineral fertilizers at the rate of 100 kg ha'1yr'1 (Bradshaw 1997:50-51), or a single
application of sewage sludge (Bradshaw 1997:52, Table 4.6).
Bacteria and fungi can survive when native topsoil is stockpiled for later use, if it is
stockpiled at rooting depth of native vegetation and replaced soon after stockpiling.
Bacteria and fungi are essential to soil function and are fragile, however, they readily
colonize new soils and do not need to be added (Bradshaw 1997:49). Mycorrhizal
fungi, however, require special attention. Seeds need to be sowed into soil with
mycorrhizal fungi, then transported to the site, or skeletal soil can be inoculated with
fungi appropriate to the regional climate (Haselwandter 1997:71) by scattering
appropriate soil on site before planting after soil acidity or heavy metals are reduced.
Metals can be mediated by planting metal tolerant species only if they are part of the
native assemblage. Heavy metals can be alleviated with addition of organic matter and

add nutrients (particularly nitrogen) within 5 years and as needed thereafter (Bradshaw
1997:59). Covering the heavy metal contaminated area with 30-50 cm of
uncontaminated material (Bradshaw 1997:59)is also possible.
Microorganisms need no attention because they colonize skeletal soils rapidly except
where legumes are native to the area, and then rhizobia must be inoculated (Bradshaw
Annelid survival is dependent upon soil with appropriate chemical conditions,
therefore, soil should be tested prior to intervention, and then earthworms can be
imported to the site. Based on the soil test, toxicity and acidity must be reduced to
native conditions. Lime is the only method to neutralize acidity, which is related to the
amount of unweathered pyrite in the soil (Bradshaw 1997:58). Lime should be applied
at 20 to 150 tons ha'1 (see Costigan, Bradshaw, & Cemmell 1981)
Restoring Physical Conditions that Support Native Species
"Communities in which there has been a strong human influence have largely been
ignored by ecologists; yet ... ecological processes still operate in such communities, and
the restoration or reconstruction of vegetation to a state comparable with that occurring
naturally presents almost the ultimate challenge to ecologists in the application of their
science." (Webb 1997:133)
Responses by design discipline to meet ecological target conditions are largely implied
and follow directly from data gathered in the above analysis. For example once physical
site conditions in need of repair are documented, the appropriate design and planning
response is to form directions to effect repair. Following are guidelines that are not
revealed in the above analysis but may be "best practices" revealed in unrelated but
similar restoration efforts. 1 2
1. Restoration unit. Restoration of the full natural hydrologic would return natural
energy and nutrient cycles to their natural functions and processes. Because the
natural hydrologic functions at every scale and its history can be determined,
restoration of natural hydrology can be accomplished by design and planning at
any scale. However, because primary hydrologic orders are affected by lesser
orders, analysis of any order should include all lesser orders that affect it
throughout the watershed.
2. Priority areas. Specific areas of priority restoration should be identified based
upon areas with special ecological attributes (Forman and Collinge 1996:556).
The above analysis will have identified areas with endemic or obligate species

and highly vulnerable components, and areas where a landscape stands on a
gradient of land transformation. These should be given higher priority in
restoration and any area with 90% natural vegetation should be automatically
removed from all proposed socio-physical development. Scattered spots within
natural-vegetation landscapes (Forman and Collinge 1996:557)with rare species
and habitats should be protected along with large pristine areas. Whole
landscapes of natural vegetation should be protected and meshed with other
3. Plan regionally. Transportation, infrastructure, and land areas to be used for
socio-physical development should be planned at regional scale.
4. Degraded areas. Restore native plant species to function in ecological
successions appropriate to the area to repair degraded areas.
5. Fragmented areas. Restore fragmented areas to contiguous whole landscapes
by: bridging riparian and open corridors with roads and infrastructures rather
than paralleling them; restoring native vegetation; and rerouting infrastructure to
eliminate disruptions to connectivity.
6. Non-native species. Remove all non-native (exotic) plants or restore native
species to overtake non-native species.
7. Crain/mesh. Restore native vegetation to grain/mesh that is appropriate for
native fauna (Forman 1995:268).
8. Disturbances. Restore natural disturbances or simulate them where they cannot
be restored. Allow ecological successions consisting of native species to recover
Implementing Compatible Socio-Physical Form
Because so much of the natural environment is already affected by socio-physical
development, it is tempting to discount previous biophysicl losses and to concentrate on
saving what remains. If it were possible to view anthropogenic disturbances from
nature's point of view, such disturbances are simply more disturbances. The extent and
duration of anthropogenic disturbances is what compromises ecosystem integrity, but
both are subject to change. The following outline illustrates how change to socio-
physical systems is possible: 1
1. Identify opportunities for minimizing biophysical losses and to make them
a. Socio-physical environments can change because everything has a life
with birth, adolescence, maturity, and death. Decaying socio-physical
environments allow opportunities to reconsider anthropogenic goals and
means to achieve them without significant social, economic, and
political disruptions.

b. Natural disturbances frequently affect the socio-physical environment
causing major disruptions to human life. After any single natural
disturbance, society can give considertation to anthropocentric goals in
a manner that reduces risk to socio-physical institutions and/or
redevelops in a sustainable manner, and with consideration of
ecological objectives.
c. Natural stochastic disturbances are random in space and time and reset
successions so that regional landscapes always encompass a variety of
serai stages. This variety allows socio-physical disturbances to exist at
similar seres
d. Development of the socio-physical environment usually results in
pockets of forgotten spaces that can be utilized to meet ecological
e. It may be helpful to consider socio-physical environments as interim
conditions within biophysical environments with the entent of returning
to natural biophysical states.
2. Identify alernative responses.
3. Identify any hybrid responses derived from alternatives.
4. Adaptive management
a. Monitoring and evaluation
i. Species
1. Native and exotic
a. Abundance
b. Distribution
The use of any procedure to protect ecological diversity should pivot around a set of
ecological thresholds within a historic range of viability. If thresholds were clearly
marked then conflicts could be evaluated prior to any development occurring and
restorations would be implemented to achieve known objectives. Whereas ecological
thresholds are not mapped, they can be interpreted from maps. Once ecological
thresholds are known and localized, meeting ecological thresholds could be achieved
by using a variety of tools.
Purchases Land areas that play key roles in ecological function or process can
be purchased by using public funds, matching funds, or open space grants.
Leases Term leases can be used to obtain property rights to land that is either
not available for purchase or where the purchase price would be too great.
Donations/bequeathals. People and institutions that own land with high
ecological value can be encouraged to donate or bequeath it to a public agency
whose intent is to preserve or restore it.
Transfer/purchase development rights The right to develop an ecologically
valuable site can be traded for a site that is less valuable.

Exchanges In rural areas where the human population is declining,
ecologically valuable sites can be made cohesive by closing rural roads to
compile larger agricultural plots. Because these public road spaces would be
added to private use, they could be exchanged for private land that is ecological
valuable and unprotected or in need of restoration. Or they could be
exchanged for the restoration and conservation easement of the ecologically
valuable site.
Incentives Encourage development and re-development in the most common
areas and away from unique and/or rare landscapes.
Mitigation The zone of disturbance at ecological valuable sites can be
minimized by (Duerkson et al. 1997:7): buffering roads and structures; avoid
ecologically valuable areas by site design; vegetation management; and pet
Management Limit human effects by managing the type, intensity, and
location of socio-physical development (Duerkson et al. 1997:7).
Design/Planning to Assure Ecological Conditions
1) Site Identify geographical limits of study site.
2) Aerial coverage Obtain aerial photograph and topographic map of study site that
includes surrounding area. The aerial photograph should contain a minimum often
times the area of the site. More coverage of the surrounding area will provide a
more complete picture of the macro ecology of the region and thus enable
design/planning recommendations that conform to a wider perspective.
a) The scale of the aerial photograph should be convenient to the user. To
eliminate conversion between acres and hectares, the aerial photograph should
be at a scale that will make conversions unnecessary. I prefer to use ratio scales
that are common to metric units so hectares can be measured and plotted as a
grid overlay.
b) Aerial photographs can be ordered in any scale from any aerial surveying
company or predetermined scales from communities or public utility
3) Coverage area Calculate the aerial photographic coverage either in acres or
hectares. Because scientific literature is usually given in hectares, acres will have to
be converted to hectares. The following conversions factors will be useful:
i) 1 foot = 0.3048 meters
ii) 1 meter = 39.37 inches = 3.2808 feet
iii) 1 acre = 0.405 hectare
iv) 1 hectare = 2.471 acres
v) 1 hectare is 100 meters X 100 meters = 328.08 feet X 328.08 feet
vi) 1 square mile = 640 acres (approximately 249 hectares)

4) Topography Add topography to the aerial photograph. Because aerial photographs
at larger scales provides more information on existing vegetation and differences in
vegetation on various slopes and effects of solar exposure, contours added to the
aerial photograph allow more in-depth site study.
5) Drainage On an overlay, add all streams and drainage to the entire coverage area.
a) Draw a line on the overlay where contours converge and narrow indicating
water would collect and flow in troughs. Because troughs collect water, they
also support the most vegetation that supports the most wildlife.
b) Draw a line on each side of the drainage trough at 100 meters (328 feet) from
the center of the trough. Total width will be 200 meters (656 feet) wide.
6) Upland connectors Each drainage trough will terminate at a ridgeline or hilltop.
Because drainage patterns are tendrils that dead end, but attract and support
wildlife that do not normally reach the end of tendrils and backtrack, it is necessary
to provide connecting elements where wildlife can network with other drainage
troughs. Provide 200meter minimum width connecting corridors between ends of
drainage tendrils that provide wildlife a variety of movement options.
a) The combined 200meter wide drainage tendrils and upland connectors
generally define land areas that contribute the most to native plant and animal
i) Plan all socio-physical development to remain clear of these corridors and
remove existing socio-physical development at the end of the useful life of
such development.
7) Identify and protect all unique and atypical geographic and geological features in
the coverage area.
8) Identify required mesh/grain for each native species within the coverage area and
restore and maintain.
Nearly all of this procedure is possible with the advent of graphic information systems
(CIS) and is no longer merely desirable but is an attanable goal.
Disturbances to ecological processes will be an inevitable outcome of socio-physical
development. However, disturbance itself is a natural and necessary condition for
healthy heterogeneous ecosystems. Damage from socio-physical development is,
therefore, not due to intervention, but the lasting fragmentation of the biophysical
environment and complete removal of large segments of land area from recovery. If we
wish to retain enough primary production to support humanity, remaining fragments of
native ecosystems must be preserved and/or restored to a condition that supports
natural process and function. This can be accomplished if the built environment is

aligned with ecosystem integrity. This alignment would require that: socio-physical
disturbances follow natural disturbance patterns; recovery due to natural succession is
incorporated into the design of the socio-physical environment; and conditions of
biophysical restoration accompany all socio-physical interventions. Because our
intervention begins with design and planning, it is fitting to design and plan for survival
of natural process and function.
At an elemental level, it may be possible to know ecological minimum conditions of
natural function and process. They can be determined by hypotheticodeductive study
and observation. Manipulative experiments, however, may not reveal emergent
patterns, processes, and anthropogenic effects to regional or global spatial and long
temporal scales. From a planning perspective, it is more valuable to take safe measures
to preserve and/or restore complete ecosystems to a condition that supports minimum
viable and effective populations of all native species, than to wait on data that may not
arrive in time to do any good.
Recovery from anthropogenic disturbances is possible if such disturbances are limited to
temporal and spatial scales of natural disturbance patterns. In this way, minimum
dynamic ecosystems can be retained that assure all extant biological families remain to
contribute to ecosystem recovery. However, no recovery is possible unless land is still
available to be recovered. To avoid precluding land from recovery, developed land
must either contribute to natural ecosystem processes or development must occupy
land that never significantly contributed to ecosystem productivity. Because the
landscape ecology usually supports a broader regional ecology, it is also necessary to
institute measures that return disturbed land to productivity. Land with relatively poor
productivity can be occupied, and grain/matrix size and canopy closure appropriate to
native species can become a normal part of the socio-physical environment. This will
help to assure traditional movement of species between habitats and contribute to
functions of source and sink habitats.
The above conditions assume that minimum dynamic systems still exist and recovery is
possible. A quick observation of an aerial oblique photograph for most areas of human
habitation proves that little exists of the natural biophysical world in many areas. The
land is extensively fragmented by infrastructure, and has been transformed into patches
of agricultural monoculture and urban development. What remains of natural systems is
land that is least hospitable to human uses streams and rivers that are susceptible to
flooding or are too steep or too muddy to plow exist as remnants of natural systems.
Because these areas are also most valuable to most wildlife and plant species, they still
contribute to natural ecosystem processes and functions. The normative condition for
natural function and process should be that condition that has the ability to maintain
itself. If that condition remains, it should be retained, if lost, it needs to be restored.

Restoration of the ecosystem is possible if ecosystem remnants are reunited into whole
units and reinforced by reconfiguration of the landscape into minimum dynamic areas.
Development of the socio-physical environment can assure ecological minimum
conditions if these minima are an integral part of socio-physical interventions. First, any
fragmentation of any landscape should be accompanied by equal and opposite
defragmentation or unification of the affected or the most valuable adjoining and
contributing ecosystem. This is possible by reconnecting fragments by road closures,
bridging ecologically valuable connecting elements, restoring connectivity and networks,
and restoring grain/matrix size and/or canopy appropriate to native species. Second, any
permanent spatial disturbance must be accompanied by equal and opposite spatial
contribution to minimum dynamic area. This can be done by transferring what cannot
be saved in one location to another where it can be saved and will also contribute to an
altered, but viable cohesive ecosystem.
To assure ecological conditions relegates socio-physical environments to the piedmont
and upper plains, and connected by transportation corridors that transect riparian
corridors. This arrangement is compatible because it removes people from areas that
pose risks to human life and property and provides people with sufficient land that is
less valuable to non-human life. Resources to accommodate the 15% of native species
that do not rely upon riparian corridors must be set aside elsewhere. Because so much
of the biophysical environment is already compromised by socio-physical development
and more is inevitable, a restoration strategy is essential if biophysical losses are to be
stemmed. Restoration ecology should be first applied where the greatest gains are
possible in the shortest time, i.e., in marginally productive agricultural lands (Meffe et al.
1997:488). Wetlands and riparian corridors are prime focus areas because they are the
basis of many of the biotic processes and functions, and also contain a richer variety of
biotic life to act as base material from which restoration can proceed.
To achieve a more accurate picture of what environments should be publicly acquired,
it is essential to: 1) inventory the landscape to define all endemic areas; 2) define all
drainage troughs and demarcate a 200 meter wide corridor centered on these troughs;
3) provide upland connections for the above corridors at minimum widths of 200
meters; and 4) supplement land area where native assemblages required larger ranges.
Once that is accomplished, communities, governments, institutions, and individuals can
begin to acquire and dedicate such land areas as natural areas. Ecologically valuable
lands held by individuals can be traded for private lands that are less ecologically
valuable and have a higher socio-physical value. Trades can be vehicles to compensate
individuals for takings. Designers and planners can create the socio-physical
environment to restore and protect natural drainage, grain/matrix, recovery from
temporal and spatial disturbances, and reconfigure connections between socio-physical

Essentially, this procedure combines a fine-filter approach that protects endemic areas
and coarse filter approach that protects remaining samples of the most ecologically
valuable land area with a strategy to recover complete ecosystems from prior and future
anthropogenic disturbances. However, it recognizes that humanity is also a part of the
ecology and must be accommodated without threatening the natural systems that make
human life possible. This procedure calls for a new consciousness of land use that is
conservative because we know so little. It also calls for reconfiguring of socio-physical
development patterns for the benefit of other life and ultimately our own. If scientists
later determine that we know enough to be less conservative, we have not lost more in
the interim. This strategy adequately represents all ecosystem types, the species they
support, and the resulting natural process and function. This proactive procedure thus
establishes environmental protections that could have the most comprehensive effect
on ecosystem process and function, addresses prior losses and fragility of remnant
ecosystems, and provides the most temporal and spatial flexibility for changing plant
and animal communities.

"What counts as care for the land or sound management practice in the forest does not
translate directly into care at the urban level." Marcia Muelder Eaton (Nassauer
The goal of this chapter is to apply and validate a procedure for aligning the build
environment with ecosystem integrity. Case studies related to land-unit, local, and
landscape scales are explored to determine how ecological minima can be applied to
the real landscape; what application means to the form of the socio-physical
environment; and to refine the procedure based upon what has been learned. Site
selection for these case studies is based upon anthropogenic land use rather than type
of ecology. Land use appears to dictate restoration strategy more than ecology because
species sensitivity to human presence restricts species use of all ecosystems. All
restoration must at least deal with landscape scale issues. Activities and decisions made
at smaller scales must always support ecology at large scales.
The Procedure
1) Site Identify geographical limits of study site.
2) Aerial coverage map of study site that includes surrounding area at least ten times
the study site.
3) Coverage area Calculate the coverage area in hectares.
4) Topography Add topography to the coverage area.
5) Drainage On an overlay, add all streams and drainage to the entire coverage area.
a) Draw a line on the overlay where contours converge and narrow indicating
water would collect and flow in troughs.
b) Draw a line on each side of the drainage trough at 100 meters (328 feet) from
the center of the trough. Total width will be 200 meters (656 feet) wide.
6) Upland connectors Provide 200meter minimum width connecting corridors
between ends of drainage tendrils that provide wildlife a variety of movement
options. Plan all socio-physical development to remain clear of these corridors and

remove existing socio-physical development at the end of the useful life of such
7) Identify and protect all unique and atypical geographic and geological features in
the coverage area.
8) Identify required mesh/grain for each native species within the coverage area and
restore and maintain.
The subject of case studies 1 thru 3 are nested within a section of the South Platte River
drainage from Brighton to Greeley and tributaries from the west including portions of
Boulder Creek, South Boulder Creek, St. Vrain Creek, Coal Creek, Little Thompson
Creek, Big Dry Creek, Little Dry Creek, Left Hand Creek, and numerous tributaries east
of the Font Range of the Rocky Mountains. This area is in east Boulder County from
10519'00"W and north of 3957'55"N plus the south-west portion of Weld County to
10445'00"W and south of 4019'48"N. The total area defined by these boundaries is
approximately 119,110 hectares. Because the first three case studies are part of the
grassland ecosystem, the generalization of this theory across all landscapes was not
initially tested. A forth study that deals with a mountainous forest/meadow ecosystem
was conducted to determine variations in usability of the restoration procedure. The
mountain/meadow ecosystem case study informs of the generalizability of the proposed
strategy for incorporating ecological determinants to guide design and planning, but an
extensive investigation would need to be done to determine the extent of applicability
across all ecosystems and landscapes. This strategy may need to be refined to be useful
for specific ecosystems; however, the basic procedure described in Chapter 3 will
provide the framework for use in all ecosystems. A fifth case study is in the Ponderosa
pine ecosystem and is included here to contrast to the first four studies and to illustrate
how this procedure can be applied to a study site where design and planning
alternatives are limited by location, site configuration, and legal restrictions placed upon
the site.

Case Study No. 1
Land-Unit Scale/Urban Fringe/Crassland Ecosystem
The land-unit scale in the grassland ecosystem used in this case study is a site nested
within case studies 2 and 3. This nesting is intended to give a range of application to
show how scale influences the way application theory is applied. The intent of studying
the land-unit scale is to learn how the designer dealing at any particular building site
can make decisions that help to assure physical conditions required for ecosystem
integrity are maintained. Because all individual sites relate to surrounding land area,
studying only the limits of any site does not provide enough data to describe those
relationships. The distinctions in the following text that refer to 'site' or 'lot' refer to an
individual building site delineated with boundary lines and a legal description. 'Land-
unit' refers to the extents of the large-scale aerial photograph where the 'site' is located.
Description of Study
1. A digitized aerial photograph was obtained from the City of Boulder and plotted
at a ratio of 1:384 or 1" = 32'. This scale allowed for the site plan to be plotted
at the same scale and superimposed onto the photograph. Note: Graphics
included within this dissertation, Figures 4.1-4.3, were reduced from the
original sizes and are no longer to scale.
2. The area was calculated and site analysis was done for the entire area shown on
the photograph (see Figure 4.1). The actual project site, Figure 4.2, as identified
below and superimposed onto the photograph is necessary to identify strategies
for site development and retaining and/or restoring physical conditions
appropriate to ecosystem function and process. However, the entire photograph
is analyzed because restoration strategy must be developed within a context of
surrounding land uses.
3. Landform was analyzed to determine historic drainage patterns.
4. A survey of historic range of variability was conducted as per the procedure
developed in Chapter 3 and is summarized below.
5. Field observations were conducted to identify remnant and restored natural
areas. A design objective to retain or restore physical conditions appropriate for
ecosystem function and process would have influenced placement of the
structures on the site, drainage patterns and mitigation of altered drainage, and
landscape materials. Because development took place with a vague idea of
restoration concepts, but prior to this dissertation, some development decisions
were made correctly and some problems were identified during this analysis.

6. A ten-meter square grid was superimposed on the identified remnant natural
areas. Total natural area was calculated.
7. The development site was analyzed to determine how remaining natural areas
function in relationship to other identified natural areas, and problem areas
were identified along with a strategy for restoring connectivity to fragmented
natural areas.
8. The development site was analyzed to compare historic and developed
drainage patterns and make decisions that did not alter historic patterns.
Survey Documenting the Study Area
Description: A portion of the South Platte drainage area near the western edge of the
study area as described at the beginning of this chapter.
Location: Lot 11 Crestmoor Subdivision, Boulder County, Colorado
The immediate surroundings are included in the land-unit scale study to
provide context for the site. The particular site comprises 0.02446
hectare of the 0.516hectare aerial photograph coverage area.
Elevation: 5358-5392'ASL (on the site)
Climate: Semiarid with annual precipitation less than 20 inches.
Annual average temperature is j+50F with 40F day/night variation.
High wind speeds with drying effects combined with high temperatures
cause summer droughts. Snowdrifts are not common at this site.
Large seasonal and annual climate variations (Mutel and Emerick
Ecoregion: Dry Domain 330 Temperate Steppe Division (Bailey 1995)
Eco-climate zone: BSk Temperate semiarid: evaporation exceeds precipitation
with at least one month below 0C (Bailey 1995:64-5)
Zonal soil type: Chestnut, Brown soils, and Sierozem (Bailey 1995:66)
Zonal vegetation: Shortgrass
Potential Primary Production: 8.2 t/ha/yr
(Bailey 1995:65)
(Bailey 1995:47)
A-horizon eluvial (washed from)
B-horizon illuvial (washed into)

Young, sandy, sandy-clay soils developed from soils blown in and glacial
deposits. Upper surface is strewn with glacial deposited stones of great
variety. Soil below surface is fine clays. (Mutel and Emerick 1992:29)
Original drainage: Soil percolation recharge
Surface drainage to salt marsh below to west
Geographic characteristics:
Steep-sided mesa fascia at west terminating in mesa at east.
Role played for obligate species: None evident.
Role played for endemic species: None evident.
Flora and fauna: Appendix B
Natural disturbances: Prairie fires
Anthropogenic disturbances: Domestic livestock grazing
Due to the steepness and arid conditions of the site, it
was never plowed, and likely received little grazing by
either native or domestic wildlife.
Road was likely graded early in 1960
Ecosystem Attributes:
The following site analysis is based upon the guide for design/planning procedure to
assure ecology from Chapter 3.
1. Generally American bison, Bison bison, and the gray wolf, Canis lupus, were the
largest herbivore and carnivore in the grassland. Bison scarified the soil
providing opportunities for plant germination. Wolves likely kept the population
of hares and rodents in check along with raptors and reptiles. The loss of bison
and their replacement with domesticated cattle limited opportunities for native
plants and animals that depend upon them, and cattle and sheep have different
eating habits that do not allow native grasses to recover producing increased
stresses on native plants. Wolves were replaced with coyotes, however, because

they prey on different species, other assemblages took the place of native
2. Obligate and endemic species do not seem to have been supported by this land
3. At this land-unit scale, some native biodiversity is retained in natural and
restored areas. These are included in Appendix B and generally consist of the
smaller mammals, most birds, and reptiles. This area supports a broader
ecosystem for larger ranging species and may contain minimum dynamic areas
for some smaller ranging species. These areas are identified in Figure 4.3.
4. The extent of the whole ecosystems, that extant native biodiversity is a part, is
identified in studies 2 and 3 below.
5. Indispensable and favorable spatial patterns are shown on Figure 4.3.
a. Because the scale of most land-units is too small to include minimum
dynamic areas for all but the smallest animals and would be vulnerable
to disturbances, all land-unit scale sites must be part of landscape
b. This land-unit is part of an upland ecology that supports a riparian
ecology. To do so, upland natural areas need to be linked and form a
corridor system that includes riparian systems.
c. Connectivity between patches needs to be restored with wide corridors.
Width is relative to species movements and is narrow for smaller
species. Whereas narrow corridors would suffice for most species, this
area is intended to support broader ranging species that would require
wider corridors that are also desirable for providing redundant paths for
smaller species.
d. All native and near-native vegetation should not be built on and socio-
physical development should plan to restore physical characteristics that
assure that natural areas function as contiguous whole systems. When
development is inevitable, then the strategy should be to intervene with
the lowest impact possible and retaining historic drainage and water
infiltration characteristics. Non-native vegetation should be avoided or
contained within small outdoor spaces with clear demarcations between
native and non-native areas. Shade trees when applicable should be of
native species and placed close enough to provide desired shade. The
development goal should be to create a non-native intervention zone
that is as small as it can be and strictly adhered to. In the grassland
ecosystem, most of the land should remain in grasses with almost no
trees. Adding a structure or trees changes opportunities, so when both
are required they should be contained within the same small envelope.
e. All of the land in this study area is essentially of the same quality, so
there is no ecologically less valuable land where development would
have less impact. Likewise, development is restricted by legal

boundaries rather than ecological particulars. Development, therefore,
requires making interventions that result in the least losses and provides
opportunities for maximum restoration,
f. The only intervention appropriate to intervention at this land-unit scale
is to support minimum dynamic areas to which this land-unit is a minor
part. This is important because each land-unit scale contributes
something to a larger system, if losses to each were acceptable because
of their minimal singular impact; cumulatively they constitute a large
6. The extent of existing and proposed socio-physical disturbance to ecological
thresholds is the physical loss of grassland area and fragmentation of natural
area. These are shown on the aerial photograph and site analysis in Figures 4.1-
4.3. Topography is indicated on Figure 4.2, however, a comparison between
historic topography and extant topography is not possible. Development was
done with the intention to retain existing topography, however, was altered
where excavation and backfill was necessary to install the structure and to solve
a topographic problem created by developing a neighboring site. Figure 4.3
identifies the relationship of this site to the watershed, which was retained
during and after development.
7. Any socio-physical development on this site is in conflict with biophysical needs.
The only possible responses are to: (1) leave the landscape completely native;
(2) minimize interventions; and (3) recover from interventions by restoring
connectivity by linking patches with native vegetation.
8. Restoration will consist of repairing native grassland, elimination of non-native
vegetation, containing and separating non-native vegetation from native areas,
and reconstructing links between native and restored patches.
9. Physical site conditions in need of repair include:
10. Climate is not appreciably changed.
11. Flydrologic cycle is retained.
12. Natural hydrologic regime is altered by increased runoff from hard surfaces.
Runoff is reduced to historic conditions by diverting runoff from hard surface
onto grassland at short intervals. Theoretically, grasses subject to increased
runoff have different growing conditions from native grassland. Differences are
minimized by more frequent water diversions and if there are any affects, they
are not obvious.
13. Surface soils after disturbance tend to be substructure material. Because original
soils showed some development in the first six inches, some soil should be
added to the surface to simulate natural conditions.

Ecological Evaluation
The study area can be summarized as follows:
Study area 26,550 m2 originally grassland
Native species supported S = 16.3A016 (Payne and Bryant 1994)
S = number of species
A = area in hectares
S = 16.3 (2.655ha)016 = 19.06 mammal spp.
Remaining grassland 5160 m2 (native and restored) or 19.44% of
original could still function as habitat for native
Potential mammalian species supported by remaining grassland
S = 16.3A016 (Payne and Bryant 1994)
S = number of species
A = area in hectares
S = 16.3 (0.516ha)0'16 = 14.66 mammal spp.
The loss of 4.4 species components is based upon the loss of habitat.
However, because some of this habitat is now occupied by non-native
species, the loss of native species is greater than 4.4 species. In addition,
this area is much too small to support wide-ranging species such as
bison, wolf, elk, deer, etc. so the loss of habitat at the land-unit scale
also contributes to losses at the landscape and regional scales.
Socio-Physical Development Interventions
11 April 1981 Excavated for foundation
There was no place to put the excavated soil, and since it was all to be
returned as backfill, it had to be piled adjacent to the digging on top of
near-native grassland.
If subdivisions are to be plotted in similar areas, there should be
provisions made for placing excavated soil until it can be
It could be placed where garden or driveway is to go, or
within a temporary bin placed on site above vegetation
not to be disturbed.
Driveway was excavated at time of foundation excavation and surfaced
first with red ash clay from a burned underground coal mine, but was

later surfaced with road-base because the ash was too light and washed
out in thunderstorms.
4 June 1981 Backfill installed around foundation soil taken from piles on site.
June 1981 Site had to be re-graded from natural grade on southwest corner because neighbor to the south had piled earth on the northwest corner of his lot leaving a big pile that had not been used and was to remain. The site was replanted with "Foothills mix", a mixture of 18 different kinds of grass seed native to this area. Few of the grasses germinated until the following spring and summer. There was an influx of weeds, primarily tumbleweed. Crested wheat was the most predominant grass to dominate the site, but over a period of about 5 years, succumbed to shorter grasses.
June 1984 Garden was leveled and compost pit installed. All precipitation landing on garden percolates into ground. There is no runoff from garden. Organic material has been added to the garden every year, changing soil characteristics and plants that can grow. All household organic matter has been added to the compost pit and has decomposed and subsequently added to the garden. Compost and garden has provided habitat for mice, bullsnakes, garden snakes, tiger salamanders, and a variety of insects and annelids.
March 82 June 87:
Trees and shrubbery were added to the site. Because of a steep
April 1990 excavation cut on the neighboring site to the south that threatened the stability of the southern boundary of this site, Pfitzer juniper bushes were planted at 5' spacing along approximately 50' of the southern property line. They have also been planted along the north edge of the driveway and on each side of the driveway at the street. All trees planted are evergreens except: 1 green ash, 1 red oak, 1 maple, and 1 Shademaster locust. All bushes are junipers except for 1 lilac and 4 Concord grape vines. 9 ponderosa pine trees and 1 Austrian pine was planted on the western half of the site.
July 1996 2 apple trees were planted along the road.

Effects of Socio-Physical Disturbances
Early disturbances before on-site work allowed opportunities for influx of deer mice,
Peromyscus maniculatus.
Road Cut. The road cut altered drainage pattern, however, because the overall
slope of the hillside was not changed, most precipitation continued to percolate into
ground. Heavy thunderstorm drainage flowed northwest toward a natural salt marsh
and contributed to recharge, but from 1870 on, East Boulder and Enterprise irrigation
ditches intercepted surface flow. Changes to site drainage have not affected that
Overburden. Overburden from excavation likely killed the microorganisms in
the soil and allowed the influx of some weeds. Because microorganisms are quickly
replaced, no lasting effects are anticipated. Some bindweed and other weeds still exist;
however, native grasses have overtaken most. Some weeds may have been common
among native vegetation and are unlikely to have appreciably changed the native
conditions. Cheatgrass is present in disturbed areas, however, it has either not been
able to establish itself in healthy grassland areas or has been pushed out by restored
native grasses.
Planting. Non-native grasses allowed the site to recover, but temporarily allowed
opportunities for non-native insects and small mammals to occupy site. Trees added to
site have given shade for the house; however, have provided opportunities for non-
native mammals and birds that have eliminated the meadowlark habitat.
Retaining Walls. Rock retaining walls have changed the grading and surface
drainage and increased habitat for salamanders and allowed short-tailed shrew to move
onto the site. Drainage is altered at the micro-level, however, has not changed overall
site drainage. It has allowed exotic grasses and flowers to exist, however, most of those
are contained within the retaining walls and have not changed the native vegetation
beyond the retaining walls.
Carden. The vegetable garden introduced new microorganism, provided habitat
to non-native insects, mammals, and birds. Has eliminated native grassland, and
provided a barrier to continuity of native grassland along the eastern boundary. Praying
mantis is now a permanent resident of the site where they were once rare or non-
Driveway. The driveway allowed increased runoff. Because this runoff occurs
during thunderstorms, the amount of total runoff from the site is likely not appreciably
changed from native conditions. It is, however, a nuisance requiring the driveway to be

frequently regraded. Soil lost to erosion is imported soil used as road base and is easily
replaced (although it is a loss to some other ecosystem).
Outdoor Shower. The outdoor shower increased groundwater percolation into
soil. The overall affect is negligible. It does not affect the grasses and likely contributes to
the growth of imported trees.
Irrigation. Supplemental watering may increase groundwater percolation into
soil, but is largely offset by the increased use of water by non-native plants and lawn.
Lawns. Although the lawns are very small and contained, they offer habitat for
annelids, birds, bedding places for deer, and food supply for birds and raccoons.
House. Installing a house on this site has increased the runoff from the site
during heavy thunderstorms, but has not changed the percolation into the soil for snows
and normal rains.
Generally socio-physical development in all forms in any grassland environment alters
the opportunities for native and non-native species. At the scale of a complete natural
ecosystem, there does not seem to be any way that socio-physical development and
native grassland ecosystems can co-exist. At the smaller scale of individual species, open
space surrounding buildings and non-native vegetation may be able to contribute to the
function native ecosystems by providing habitat that may serve as sources or sinks. If so,
it is useful to restore grasslands adjacent to and among socio-physical developed areas.
Because the size and character of these areas can be determined, it is possible to
deduce which species may be able to utilize these restored grasslands.
Restoration is technically incomplete until all of the native components exist in their
native trajectories. However, this study area is too small to accommodate minimum
viable populations of some of the native species and at best could only contribute to the
total land area needed to support some species, e.g. bison. If this area represented a
cohesive natural environment and excluded non-native landscape features that favor
generalist non-native competitors and predators, sizes of remaining surrounding
grassland habitat are sufficient to support all of the native Embarizidae, Columbidae,
Corvidae, Picidae, Strigidae, some of the native Falconiformes, all Chiroptera, Rodentia,
Lepidosauris, Anura, canids, and deer. The addition of socio-physical features to this
grassland, e.g. buildings and building characteristics such as eaves, trees, paved
clearings, utility poles, lawns, gardens, and fences not only eliminate native grassland,
they also create barriers to movement of native species, habitat for non-native

competitors, and increase edge area and reduce interior area. If the remaining native
and restored grassland is to function as habitat for native species, it can do so only by
supporting other more cohesive native and restored grassland that is beyond the effects
of non-native generalist species. Because so many animal families could still exist in this
area, it is essential that the remaining grassland be connected to function as cohesively
as possible.
Restoration efforts that contribute to cohesive native grassland ecology can be
accomplished by the following efforts:
Hydrographic. Surface drainage has not changed much and needs little
restoration. Precipitation generally percolates into soils as it has. The one exception is
that the driveway has allowed runoff. Although it is a dirt drive, heavy thunderstorms
can easily overwhelm it and erosion is likely. Driveway should be graded and trenched
to rapidly direct water from the drive onto adjoining grassland. Although this could
increase drainage onto grass, there does not seem to be sufficient drainage that will
cause any appreciable change in flora.
Soil. Soils should have been protected during excavation. Because overburden
was placed on native soils and plants, the microorganisms were likely lost from most of
the site, however, microorganisms repopulate within days after disturbance. There may
have been a reduction in some kinds of ants, but these too repopulated early. Bison
formerly provided microorganisms and then domestic cattle, but they have been gone
for many years so they no longer scarify the soil or leave droppings. Soil management is
necessary because full restoration cannot be achieved. Bison manure could be imported
and spread on the soil approximately every 6 years. Deer occupy the site occasionally,
but they do not have the same impact as bison and often eat more opportunistic foods
such as flowers and garden plants rather than the grasses. Scarification of the soil is
almost non-existent, however, because most artiodactyls prefer more shallow slopes for
grazing, they would likely have not traversed this site even in historic times.
Habitat. Restore grassland and remove non-native vegetation as much as
practical. Eliminate trees except as needed for shade and/or windbreaks. Eliminate
opportunities for non-native species nest and den sites by removing non-native bushes
and screening of culverts. Restore connectivity of this site with other adjacent
grasslands. Reconfigure the garden to allow wider connectivity between native
grasslands to north and south of this site and restore native vegetation through restored
linkages between native or near-native patches of vegetation. All mowing of grassland
should be stopped to provide habitat opportunities.
Non-Native Species. The effects of non-native species on native species and
making adjustments to the socio-physical environment to compensate for those effects

are necessary. The proximity of the socio-physical environment to native habitat
provides habitat for non-native generalist species that prey upon neighboring native
species, utilize resources required by native species, and encroach upon native habitat
as sink for colonization. Theoretically, if the non-native generalists more effectively
utilize resources or reduce numbers of native species beyond sustainable levels, they
will exclude native species from habitat that is preserved and/or restored for native
species. Restoring native components, therefore, may require management of non-
native species to assure native trajectories are reestablished and maintained.
Observations of wolf restoration to Yellowstone National Park, however, indicate that
native predators keep non-native generalist species in check (Fisher 1998; Stein 2001).
Management, therefore, should be necessary only to the extent that restoration is not
Landscape Relationships. Restoring this site to grassland conditions is a good
start, but it is only one small area. It is not, however, an island because there are still
native and near native grasslands around this site that would provide some habitat
valuable to a broader region. Because all building sites in this area are developed, future
losses to grasslands are expected to be minimal (unless there is a significant increase in
the density of dwelling units allowed or smaller houses are replaced with larger houses)
and as more people restore grassland, available habitat could grow. The possibility for
increasing the amount of habitat is good by de-fragmentation of habitat, increasing
connectivity by reducing lawns, driveways, bridging to allow animal movement,
weeding, elimination of fences, and perhaps elimination of outdoor lighting and slowing
of traffic. Increasing the probability of occupation of possible habitat by native species is
limited because socio-physical development has altered the opportunities available to
species that often are at the detriment of native species.
2-5 Large Patches Across the Landscape. For most species, there is no possibility
for including 2-5 patches on this site. Even if it were possible for some very small
provincial species, the site is too small for them to be distributed beyond stochastic
disturbances. The most that can be accomplished on this site is to assure that part of the
site remains in a natural state and is connected to a larger area that functions as one of
the 2-5 patches.
Vegetated Corridors. There are no streams or drainage troughs across this site or
in the land-unit study area. This requirement is not applicable to this site or land-unit
Connectivity. Remaining natural area on this site is connected for birds and
generalist species that are less sensitive to human presence. Natural areas are not
physically connected by continuous habitat and connectivity is restricted by

anthropogenic land use. Linking isolated segments of natural area with other natural
areas to form a contiguous network can restore upland connectivity.
Obligate Areas. No native obligate areas existed
Endemic Areas. No native endemic areas existed.
Appropriate Crain. Native grassland was entirely grassland and had only isolated
trees. The natural grain was integrated with the grassland. Bare patches of
ground for example would constitute gaps within the grassland for some species,
so grassland would have to maintain some minimum grain. Native grassland at
this site was uniform with few spots with bare ground, but was easily damaged
to reveal the ground. With the site already restored to grassland, no
accommodation for grain is required.
Erosion. The matrix must be uniform grassland to function as native habitat.
Wind erosion is not a problem. Water is diverted from the driveway to prevent
soil erosion.
Heterogenity. All grassland on site is composed of a heterogeneous mix of
grasses and plants. The only homogenous part of the site is bare ground area
(driveway) without many plants, and small lawns that are intended to function
as outdoor rooms, but do support birds, fox, and deer.

582 ft =W177 m
Figure 4-1- Land-Unit Scale Aerial Photograph Grassland Ecosystem

Figure 4-2- Land-Unit Scale Site Development Grassland Ecosystem
k .
Chart Area = 26,550 sq. m. = 2.655ha
Site Area = 26,335 sq.ft. = 0.6188 acres
= 2446.6 sq.m. = 0.02446 ha

Figure 4-3 Land-Unit Scale Site Analysis Grassland Ecosystem
wj Remnant Natural Area = 5160 sq.m.

3e j" No. of sq.m, o
that remains a
Grid = 10m X 10m
4 / too
100sq.m. box tt ' **> ; TO ,19
5 Natural Area fl' 9% too tm wM .toot,-
ft tea : too too
y/'^h. / \ *22 4*v 17 OL X too
too MO <*>
.*£ ifcneed connection r X. 'Y**" ,W m
-'V? '
& ^
z m -
/. ^ need t
i* ; <*

toe B+ ' 3o
_/ .
90 A*
constriction / ^

V. "i ^

* *p; /
t : $*> m too

I -

Case Study No, 2
Local Scale/Urban Fringe/Grassland Ecosystem
The study area for this local scale contains the area for case study no. 1 and is contained
within the area for case study no. 3.
Description of Study
1. An aerial photograph was requested from the City of Boulder (see Figure 4.4).
The City has aerial photographs flown in 1999 in film positive form at a scale of
1"=1000' that could have been copied directly, however, desired coverage
would have required piecing together several photographs. Because the City
also had complete aerial coverage in digitized format, it was possible to get
seamless coverage of any area at any scale. A photograph with a ratio of 1:5000
was selected because metric scales are directly applicable and enables areas to
be calculated in hectares. The photograph was then plotted onto paper.
2. A survey of historic range of variability was conducted as per the procedure
established in Chapter 3. Results are included in the section below.
3. The entire coverage area was calculated in hectares by multiplying scaled
distance base times height.
4. A 100m x 100m grid was drawn over the entire land area. Each square
represents 1 hectare.
5. Field observation was conducted to identify remnant natural areas. These
observations were noted on the photograph and visually represented on Figure
4.5. Some of these 'natural' areas have be altered by human interventions, but
are included in this category because they either have been left idle for a long
enough time that they have recovered, are easily restored, or are in the process
of being restored.
6. Natural areas (see figure 4.7) were calculated using the hectare grid. The
percentage of natural area coverage in each grid was marked in black as a
decimal number, i.e., if one-half of a hectare grid box was green, it was
identified with a number '.5'. If the grid box was entirely green it would be
identified as a number '1' to represent '1 hectare', however, because they were
so obvious, they were not marked and merely added to the total.
7. All natural area coverage, as indicated in the hectare grid boxes, was added to
obtain the total remnant natural area.
8. The entire area was analyzed to determine how the procedure established in
Chapter 3 could be used to assure physical properties required to function in a

natural way. No matter how much natural area exists, unless it is connected to
other natural areas its value is limited.
9. Streams were identified on the photograph and 100meter wide riparian
corridors (Payne and Bryant 1994:213) were drawn on each side of streams. If
these areas could be restored, they would provide adequate connectivity
between natural patches for 85% of wildlife because they normally use riparian
corridors. Likewise, 75meter wide corridors were identified around standing
bodies of water (Payne and Bryant 1994:213). Note, that in one instance, a
ditch must be redesigned to function as a riparian corridor (described
10. A significant amount of identified natural areas was not along riparian corridors,
but could contribute to minimum dynamic areas if land uses and roads did not
fragment them. A strategy for linking natural areas was drawn on the aerial
photograph (see Figure 4.6). Natural areas were linked with restored natural
corridors of various sizes so connectivity between corridors is complete. This
was not always possible because of remote isolation of some natural areas that
were allowed to exist unattached, and a natural area peninsula that could not
be linked and was so narrow that it had little value as habitat so was discarded.
Natural area fragmentation by roads is pervasive. Because they fragment large
blocks of natural area, they represent a significant loss of habitat. It is possible to
unite separated patches by placing roads in huge culverts that can be covered
with soil and restored to natural area. These are illustrated on the aerial
photograph (Figure 4.6) and restored land area is added as indicated in item 11
11. Land area that needs to be added to complete linkages and corridors identified
above and not already calculated in items 6 and 7 above were calculated in the
same manner and identified with a decimal number to indicate fractions of
hectares. All of these fractional portions were added to obtain a total restored
land area.
12. Ecological evaluation was completed as indicated below.
Survey Historic Range of Variability
Description: The study area is in the eastern portion of Boulder County about 5 miles
east of the downtown of the City of Boulder. Pre-European settlement,
this area was entirely grassland except for sporadic trees and trees
aligning South Boulder Creek. No natural permanent standing bodies of
water exists. Two large permanent bodies of water now exist with
associated irrigation ditches across the landscape. Most developable
land is built on and much of the remaining open land is public open
space so little new development is expected.

Location: Crestmoor, Ridgelea Hills, and The Reserve Subdivisions and environs,
Boulder County, Colorado. Land area bounded by South Boulder Road
on the south, Valmont Road on the north, 75th Street on the east and
Cherryvale Road on the west.
4000'00"N and 10510'45"W
4001'45"N and 10512'45"W
Approximately 1873 hectares
Semiarid with annual precipitation less than 20 inches.
Annual average temperature + 50F with day/night change up to 40F.
High wind speeds with drying effects combined with high temperatures
cause summer droughts. Snowdrifts are not common at this site.
Large seasonal and annual climate variations (Mutel and Emerick
Dry Domain 330 Temperate Steppe Division
Eco-climate zone:
Zonal soil type:
Zonal vegetation: Shortgrass
Potential Primary Production: 8.2 t/ha/yr
(Bailey 1995)
BSk Temperate semiarid: evaporation exceeds precipitation
with at least one month below 0C (Bailey 1995:64)
Chestnut, Brown soils, and Sierozem (Bailey 1995:65)
(Bailey 1995:65)
(Bailey 1995:47)
A-horizon eluvial (washed from)
B-horizon illuvial (washed into)
Young, sandy, sandy-clay soils developed from soils blown in and glacial
deposits. Upper surface is strewn with glacial deposited stones of great
variety. Soil below surface is fine clays.
(Mutel and Emerick 1992:29)
Original drainage: Soil percolation recharge
Surface drainage to salt marsh below to west
South Boulder Creek flows year round. A dam at Gross reservoir
southwest of the study area and in the mountains restricts the
flow and occasionally stops flow.

Geographic characteristics:
This site is composed of glacial debris amid clayey silt sedimentation and
alluvial plains. Two unique geological and hydrologic features exist on
the west side of this subject area. A salt marsh on the west edge of this
subject area is one of two natural standing bodies of water in the greater
region, and a butte at the northwest corner of the subject area is a
potential site for an aerie. The potential aerie is duplicable by other
resources in the vicinity, but flora and fauna associated with the salt
marsh could not exist many other places.
Role played by obligate species: Because the salt marsh is so unusual in the area,
it is probable that some migratory species have
used the area and may continue to do so.
Role played by endemic species: The unique feature of the salt marsh makes it
possible that endemic species existed in this
area. There has been limited biological study of
the marsh and there has been no indication of
endemic species in this area. However, the
uniqueness of the geological characteristics of
this marsh warrants giving it unique protection.
The City of Boulder Open Space program now
owns most of the marsh and a project to restore
the marsh began in the spring of 2000.
Flora and fauna: see Appendix C
Natural disturbances: Grass fires
Anthropogenic disturbances: Domestic livestock grazing
Roads have been graded and paved on a one-mile grid.
Roads have been graded and paved on land subdivided for residential
Valleys and meadows have historically been used for residences and

Valleys and meadows have been developed for residences, commercial,
schools, and golf courses.
Ecosystem Attributes:
The following site analysis is based upon the guide for design/planning procedure to
assure ecology from Chapter 3.
1. Generally American bison, Bison bison, and the gray wolf, Canis Lupus, were the
largest herbivore and carnivore in the grassland. Bison scarified the soil
providing opportunities for plant germination. Wolves likely kept the population
of hares and rodents in check along with raptors and reptiles. The loss of bison
and their replacement with domesticated cattle limited opportunities for native
plants and animals that depend upon them, and cattle and sheep have different
eating habits that do not allow native grasses to recover producing increased
stresses on native plants. Wolves were replaced with coyotes, however, they
prey on different species, so other assemblages took the place of native
2. No species appear to be endemic to this area even though there is a rare marsh
located within the west side of this study area. This marsh should be protected
because of its rarity and that it likely serves obligate species.
3. See Appendix C.
4. The extent of the whole system that extant native biodiversity is a part is well
beyond the limits of this study area (see Figure 4.4) and beyond the limits of
Study Area 3 (see Figure 4.10).
5. Indispensable and favorable spatial patterns include:
a. Minimum dynamic areas are largely beyond the limits of this study area.
Natural patches play supporting roles to wider ranging species.
g. Riparian corridors are to be restored to make them freely accessible and
open to movement along their entire length.
h. Riparian tendrils and remnant natural patches are to be linked by
restoring natural corridors wide enough to accommodate native species
i. Native or nearly native ecosystems should not be built on, but may
require management to remain native. All land in this area should be
restored to grasslands except along streams where native trees may exist.
Minimum dynamic area will need to exist as grassland. Socio-physical
development should be maintained separately from grasslands as much
as possible.
j. Land area that is not designated as corridor, undisturbed native area,
restored linkages between native patches, and upland linkages is subject

to some form of socio-physical development without significant
ecological loss.
k. Natural disturbances or their simulations should be restored to the entire
land area that is the subject of this study. In native and restored
grassland patches, fire can be restored through managed fires. Flooding
should be restored to lowland areas.
l. Native grassland has been eliminated by farming, ranching, suburban,
and urban development. It has been further reduced by hydrologic
overlays of irrigation ditches and reservoirs, and fragmentation due to
socio-physical infrastructures. Fencing, roads, and human presence have
blocked movement of many species. Some native species have been
extirpated from native range and replace by non-native generalist
species. Trees and buildings on the grasslands have altered opportunities
for most species and changed the composition of species assemblages
across the landscape.
6. Native assemblages require large areas of open grassland. All socio-physical
development places something in grassland that fundamentally alters
opportunities for species existence.
7. Grassland should be restored to link native or near-native patches of the short-
grass prairie ecosystem as noted above.
8. Physical conditions in need of repair are the following:
9. Climate is not appreciably altered except in the immediate vicinity of water
10. The hydrologic cycle is partially changed by irrigation ditches and reservoirs.
This affects the landscape by supporting exotic vegetation and provides
opportunities for exotic animals to survive where they would not have.
11. Parking lots should be changed to allow water infiltration into the soil and
reduce runoff. Holding areas may be required to restore the pace of runoff to
historic levels.
12. Soil improvements may be required in restored linkages between native
Ecological Evaluation
The study area can be summarized
Study area
Native species supported
as follows:
1,872.67 hectares originally grassland
S = 16.3A016 (Payne and Bryant 1994)
S = number of species
A = area in hectares
S = 16.3 (1872.67)16 = 54.4 mammal spp.

Remaining grassland 445.8 hectares (native or near-native) or 23.8%
of original could still function as habitat for
native species if areas formed minimum effective
areas and were connected.
Potential mammalian species supported by remaining grassland
S = 16.3A016 (Payne and Bryant 1994:34)
S = number of species
A = area in hectares
S = 16.3 (445.8ha)a16 = 43.3 mammal spp.
The loss of 11.1 species components is based upon the loss of habitat.
Lost species would need to be restored, however, most of these have
minimum dynamic environments that could only be accommodated at
a regional scale. Many environments at the local landscape scale would
need to act in aggregate to form scales large enough to accommodate
bison, black bear, grizzly bear, elk, wolf, etc. To do so requires that each
local landscape is a contiguous part of a larger ecosystem. Without
connectivity that forms networks, much of the habitat in these remaining
445.8 hectares would minimally support any species requiring larger
Effects of Socio-Physical Disturbances
1,872.67 hectares originally grassland
S = 16.3A016 (Payne and Bryant 1994)
S = number of species
A = area in hectares
S = 16.3 (1872.67)16 = 54.4 mammal spp.
445.8 hectares (native)
138.2 hectares (restored)
584.0 hectares
or 31.2% of original could function as habitat for
native species after restoration.
Potential mammalian species supported by remaining grassland
S = 16.3A016 (Payne and Bryant 1994:34)
S = number of species
A = area in hectares
Study area
Native species supported
Remaining grassland

S = 16.3 (584.0 ha)016 = 45.2 mammal spp.
The loss of 9.2 species components is based upon the loss of habitat.
Based upon area alone, 1.9 less species is lost after restoration. Many environments at
the local landscape scale would need to act in aggregate to form scales large enough to
accommodate bison, black bear, grizzly bear, elk, wolf, etc. To do so requires that each
local landscape is a contiguous part of a larger ecosystem. Restored habitat at this scale
is primarily to increase connectivity and networks that would make it possible for this
area to support the regional landscape.
Grading Changes. Grading has not significantly altered drainage patterns except
in isolated areas that now retain water or drain water thus changing localized ability to
support plant and animal life. The most significant grading changes have been the
addition of dams to create water reservoirs.
Irrigation. Extensive irrigation projects were constructed in the late 19th century
that altered natural drainage patterns and made it possible for exotic vegetation to
survive. These conditions provide opportunities for non-native animal species and alter
the patterns for resource competition. With the addition of water reservoirs, standing
water and controlled release of water allows opportunities for aquatic birds and fish to
survive where they would not have historically. Ducks, geese, and seagulls are common
features of the present landscape all year, whereas, historically, they would have utilized
running water when it existed and migrated through. Cormorants and white pelicans
are now common spring and summer residents but were likely rare in historic eras.
Irrigation may increase groundwater percolation into soil due to standing bodies of
water, but increased pumping of groundwater for irrigation may largely offset this.
Farming. The introduction of monocultures reduces biodiversity. Where losses
to biodiversity are not desirable, increased management is necessary. Establishing a
sedentary life strategy centered on cultivated land attempts to exclude all nomadic and
mobile life strategies, however, it is not always successful. Migratory birds often use
cultivated fields as food resources, and because of this resource, birds may find
opportunities to exist in this area where life for them was not historically possible.
Soils. Overburden from excavation likely killed the microorganisms in the soil
and allowed the influx of some weeds. The percentage of land area covered by
overburden was never great at any one time and if microorganisms quickly recover, no
lasting effects are probable. Introduction of weeds in some areas may be problematic,
however, generally native grasslands have been able to thrive. Some weeds may have
been common among native vegetation and are unlikely to have appreciably changed
the native conditions.

Planting. Historically trees in the grasslands were primarily restricted to the
riparian corridors where varieties of Poplar trees dominated. Because the grasslands
were dry much of the time, germination and survival of trees on the grassland plain was
restricted, however, the grassland plains were probably also maintained as grassland by
animals that kept trees and bushes in check. Since settlement by non-indigenous
peoples, trees have been introduced for windbreaks, shade, and aesthetics. Introduced
exotic trees have provided opportunities for non-native mammals and birds that have
preyed on native species and utilized resources native species depended upon.
Generally socio-physical development in all forms in any grassland environment alters
the opportunities for native and non-native species. At the scale of a complete natural
ecosystem, there does not seem to be any way that socio-physical development and
native grassland ecosystems can co-exist. At the smaller scale of individual species, open
space surrounding buildings and non-native vegetation may be able to contribute to the
function of fully functioning ecosystems by providing habitat that may function as
sources or sinks. If so, it is useful to restore grasslands adjacent to and among socio-
physical developed areas. Because the size and character of these areas can be
determined, it is possible to deduce which species may be able to utilize these restored
Restoration is technically incomplete until all of the native components exist in their
native trajectories. However, this study area is too small to accommodate minimum
viable populations of some of the native species and at best could only contribute to the
total land area needed to support some species, e.g. bison. Although sizes of remaining
grassland habitat is potentially sufficient to support all of the native Emberizidae,
Columbidae, Corvidae, Picidae, Strigidae, some of the native Falconiformes, all
Chiroptera, Rodentia, Lepidosauris, Anura, canids, and deer, if this area represented a
cohesive natural environment and excluded non-native landscape features that favor
generalist non-native competitors and predators. The addition of socio-physical features
to this grassland, e.g. buildings and building characteristics such as eaves, trees, paved
clearings, utility poles, lawns, gardens, and fences not only eliminate native grassland,
they also create barriers to movement of native species, habitat for non-native
competitors, and increase edge area as it reduces interior area. If the remaining native
and restored grassland is to function as habitat for native species, it can do so only by
supporting other more cohesive native and restored grassland that is beyond the effects
of non-native generalist species. Because so many animal families could still exist in this
area, it is essential that the remaining grassland be connected to function as cohesively
as possible.

Restoration efforts that contribute to more cohesive native grassland ecosystem can be
accomplished by the following efforts:
Hydrologic. True restoration would eliminate most reservoirs and irrigation
ditches, however, because human dependency on water is so great, it is unlikely that
they will be eliminated. If irrigation projects are to remain, the alternative is to designate
restored ecosystems and socio-physical development dependent upon standing bodies
of water to different areas, if standing bodies of water significantly change the native
ecology. It may be that standing bodies of water merely provide opportunities for non-
native species such as ducks and geese that are dependent upon such resources, that do
not significantly compete with native species that never had such resources and did not
adapt to them. If so, reservoirs have eliminated habitat for native species while
providing habitat for non-native species, but also do not compete with remaining native
species for resources.
Soil. Soils have probably suffered most from the loss of recycling of elements
and elimination of biodiversity because of introductions of monocultures in cultivation.
Cultivation is to some extent made possible by the use of herbicides, fungicides, and
pesticides. Nutrient recycling has been limited by the control of fire disturbances and
the elimination of large herds of artiodacylae. Restoration of fire and grazing can help,
and are possible with elimination of fencing, bridging of roads or other traffic control,
and creating architecture and landscaping capable of withstanding rapidly spreading
short duration grass fires.
Habitat. Restore grassland and remove non-native vegetation as much as
practical. Eliminate trees except as needed for shade and/or windbreaks. Eliminate
opportunities for non-native species nest and den sites by removing non-native bushes
and screening of culverts. Restore connectivity of this site with other adjacent
grasslands. Reconfigure the garden to allow wider connectivity between native
grasslands to north and south of this site and restore native vegetation through restored
linkages between native or near-native patches of vegetation. All mowing of grassland
should be stopped to provide habitat opportunities.
Landscape Relationships. Restoring this local landscape to grassland conditions
is essential to restoration of wide-ranging species, because no single habitat area will
accommodate minimum viable populations of bison, grizzly bear, wolves, etc. Each
local landscape must support a larger biotic system. Larger ecological areas are possible
by restoring cohesiveness to ranges and territories to form areas large enough to
function as habitat with large interior area and without too much edge area.

2-5 Large Patches Across the Landscape. For large ranging species, there is no
possibility for including 2-5 patches on this site. The local landscape scale would allow
distribution of patches beyond most stochastic disturbances. Based on range
requirements for larger ranging native species and keystone species, this area must be a
supporting element to the larger landscape.
Vegetated Corridors. Riparian corridors exist across the local landscape.
Corridor restoration to widths recommended by Neil Payne and Fred Bryant (Payne and
Bryant 1994:195) are shown on the overlay drawing in Figure 4.5.
Connectivity. Natural area remnants across the local landscape are extensive,
but they are not connected in several places. Connectivity is recommended by the use
of restored natural corridors. Connection widths should be as recommended by Neil
Payne and Fred Bryant (Payne and Bryant 1994), however, they recommend basing the
width on 'edge effect'. Grassland, however, does not have any edge effect as forest
does except along riparian corridors, so recommendations for riparian corridors is based
upon buffering requirements from human activities, i.e., 98 m. Because each side of a
stream needs to be buffered, approximately 100 meters on each side of a stream must
be provided which can function as connectivity. FHowever, because corridor needs are
little understood and for other reasons unstated, 100 meters is recommended for
corridors on each side of streams and 75 to 100 meters around lakes (Payne and Bryant
Obligate Areas. Sombrero marsh was one of two native salt marshes in Boulder
County. Because it was so unique to this region, it may have supported obligate species.
Fortunately, Sombrero Marsh is already being restored and is protected by being part of
City of Boulder open space.
Endemic Areas. Sombrero marsh was one of two native salt marshes in Boulder
County. Because it was so unique to this region, it may have supported endemic
species. Fortunately, Sombrero marsh is already being restored and is protected by
being part of City of Boulder open space. No comprehensive inventory of native species
has been accomplished for the marsh.
Appropriate Grain. Native grassland was entirely grassland had trees primarily
along streams. Grain, historically, was integrated with the grassland. Bare patches of
ground for example would constitute gaps within the grassland for some species, so
grassland would have to maintain some minimum grain. Native grassland at this site was
uniform with few spots with bare ground, but was easily damaged to reveal the ground.
Restoration of grain would be included in restoration of as much of the native grassland
matrix as possible.

Heterogenity. All grassland in restored area will include grasses and plants from
all native families.
The possibility for increasing the amount of habitat is good by de-fragmentation of
habitat and improving connectivity. In some cases, restoration of connectivity will
require removal of houses in corridors, but most of these are within the floodplain and
would be threatened and possibly damaged by flooding. Beyond the need to restore
corridors, every land-unit scale should support the greater landscape ecology. This
requirement is not critical in the grassland ecosystem because it is more important to
keep the native ecosystem separate from socio-physical development.