UNIT V
ECOSYSTEM STABILITY AND ECOLOGICAL
MANAGEMENT
Structure
5.1
5.2
5.3
5.4
5.5
5.6
Introduction
Objectives
Ecosystem stability
5.3.1 Diversity and Stability
5.3.2 Functional diversity
5.3.3 Concepts of Stability
Ecology of Plant Invasion
5.4.1 Definitions
5.4.2 Conditions that lead to invasion
5.4.3 Ecology of invasion
5.4.4 Impact of invasion
5.4.5 Threat to global biodiversity
Environmental Impact Assessment
5.5.1 Assessment of Environment in India - Background
5.5.2 Environmental Impact Assessment : A Process
5.5.3 Environmental Impact Statement : The Documentation
5.5.4 Purpose of EIA
Ecosystem Restoration
5.6.1 Ecosystem health
5.6.2 How healthy ecosystems become pathological
5.6.3 Ecosystem health and human health
5.6.4 Ecosystem restoration
5.6.5 Problems with restoration
5.7
5.8
5.6.6 Prevention of ecosystem disruptions
Ecological Management
5.7.1 Ecological management
5.7.2 Current status and threats
5.7.3 Biologically achievable management goals
5.7.4 Societal factors
5.7.5 Establishing management goals
5.7.6 Adaptive management
5.7.7 A critique of ecological management
Sustainable development
5.8.1 Background
4
5.9
5.10
5.11
5.12
5.8.2 Definitions
5.8.3 Goals
5.8.4 Indicators
5.8.5 Values
5.8.6 Practice
5.8.7 So, What Is Sustainable Development?
Lets sum up
Check your progress : the key
Assignments/ Activities
References/ Further Readings
5
5.1
INTRODUCTION
Man has always inhabited two worlds. One is the ‘natural-world’ of plants,
animals, air, water, and soil of which man himself is a part; while other is the
‘built-world’ of social and cultural institutions and artifacts which he created for
himself by using science and technology, and political organization. Both the
natural and socio-cultural worlds constitute an important part of the
environment.
Thus, Environment is a quite comprehensive term that includes not only the
areas of air, water, plants, and animals, but also other natural and manmodified features like transportation systems, land use characteristics,
community structures, as well as economic stability. In other words, the
environment is made up of both biophysical and socio-economic elements. As
a result of environmental degradation due to unrestrained industrial and
technological progresses and over-exploitation of natural resources; there has
been increasing awareness in environmental issues in sustainability and the
better management of development in harmony with the environment, in
recent decades. Associated with this environmental awareness has been the
introduction of new legislation, emanating from national and international
agencies, that seeks to influence the relationship between development and
the environment.
5.2
OBJECTIVES
The foregoing unit approaches the study of ecology at individual, population,
and community levels, mainly being a descriptive approach. The main
objectives of this unit are to know the structures, function, management, and
sustainable use of ecosystem. The major objectives of present study are :

To understand the structure and function of ecosystem ;

To study the diversity and stability of an ecosystem;

To understand invasive species and their ecology;

To identify thrust areas of ecosystem and their managment;

The study the environmental impact assessment process and understand
its role on the development of country
6

5.3
To explain the sustainable use of nature and natural resources and their
development.
ECOSYSTEM STABILITY
We are at that point in the course where we are switching gears. In last four
units, we have focusing on the biological diversity, environmental pollution
and their control measures, and conservation strategies for biological wealth.
In this unit, we are going to be reading about ecosystem stability and function,
perturbation and restoration, invasive plant species and their ecology, and
ecological management. We will be reading about environmental impact
assessment and sustainable development.
Every ecosystem is subject to perturbations such as climate, nutrient
fluctuation, loss of biodiversity, and introduction of exotic species, that can
alter ecosystem structure and function. The degree to which ecosystems
respond to perturbations depends their ability to withstand perturbation and
maintain normal function (resistance) and/ or recover from disturbance
(resilience).
It is commonly believed that the more diverse an ecosystem is, the more
stable it will be. These two components of stability, in essence, address how a
system responds to disturbances and knowledge about them is key to
developing ecosystem recovery and restoration efforts. Before we can read
about this relationship, however, we need to decide just what diversity really
is.
Whittaker [1972] distinguished three types of diversity.
1. Alpha diversity—diversity within a particular area or ecosystem
2. Beta diversity—the change in diversity between ecosystems
3. Gamma diversity—the overall diversity in a landscape comprised of
several ecosystems
Rosenberg et al. [2002] studied microsatellite variation in human beings at
several hundred loci. They were able to distinguish five major geographical
groupings of populations: Africa, Eurasia, East Asia, America, and Oceania.
7
Of the total diversity in human populations, roughly 10% of the diversity is a
result of differences among the different geographical groupings. Diversity
within each geographical grouping corresponds to alpha diversity, the total
diversity within human beings corresponds to gamma diversity, and the
proportion of diversity due to differences among geographical populations
(10%) corresponds to beta diversity.
Most analyses for conservation purposes have focused only on species
diversity attempting to identify regions with a large number of species. You all
probably realize, however, that there are several aspects to diversity :

Number of different species

Relative abundance of different species

Ecological distinctiveness
differentiation

Evolutionary distinctiveness of different species
of
different
species,
e.g.,
functional
We also won’t discuss formal definitions of ecological diversity, which are
primarily definitions of alpha diversity although they can be generalized to
allow partitioning of gamma diversity into its alpha and beta components.
These definitions treat all species as equivalent, ignoring aspects of
ecological and evolutionary distinctiveness. Until relatively recently, many
experimental evaluations of the diversity-stability hypothesis did the same.
5.3.1 DIVERSITY AND STABILITY
Over the past few decades, it has been commonplace for conservationists to
appeal to the diversity-stability hypothesis as a component of their arguments
for the importance of conserving biological diversity.
Consider, for example, the following passage from Barry Commoner’s book,
The Closing Circle : The amount of stress which an ecosystem can absorb
before it is driven to collapse is also a result of its various interconnections
and their relative speeds of response. The more complex the ecosystem, the
more successfully it can resist a stress. Like a net, in which each knot is
connected to others by several strands, such a fabric can resist collapse
better than a simple, unbranched circle of threads – which if cut anywhere
breaks down as a whole. Environmental pollution is often a sign that
8
ecological links have been cut and that the ecosystem has been artificially
simplified
Principles
Robert MacArthur [2002] proposed measuring the stability of an ecosystem by
measuring the number of alternative pathways it contains through which
energy can flow. He justified this measure by arguing that an ecosystem with
many pathways, representing an abundance of species organized in a
complex food web, tends to equilibrate fluctuations in population as predators
will switch from less abundant to more abundant prey species, lowering
population densities of the more common and allowing the density of the less
common to increase.
There are six reasons for thinking the hypothesis to be true:
1. Evidence from mathematical models suggests that those with few species
are inherently unstable.
2. Laboratory experiments are consistent with the mathematical models.
3. Habitats on small islands are more susceptible to invasion than are those
on continents.
4. Less diverse habitats of cultivated or planted land are more susceptible to
invasion than undisturbed habitat.
5. Highly diverse tropical forest ecosystems are relatively resistant to pest
invasion.
6. Orchard spraying, which simplifies ecological relationships, tends to
increase the likelihood of severe oscillations in pest populations.
In 1975, Daniel Goodman summarized the mounting evidence against the
diversity stability hypothesis by responding to each of Elton’s arguments for it.
1,2 Models of more complex communities showed just the opposite of what
Elton asserted. The more species that interact the less likely the system is
to be stable.
3 The data suggesting vulnerability of islands to invasions by pest species
may result from accidents of distribution or other special characteristics of
islands.
9
4,6 Crops and orchard tree planted in pure stands do not represent
equilibrium low diversity systems. It is difficult to find evidence that
naturally low diversity communities are more susceptible to invasion than
naturally high diversity communities.
5 The tropical biota is so diverse and complex that large fluctuations might
go unnoticed. Furthermore, there is evidence that even highly diverse
systems can be dramatically altered by invaders, e.g., the impact of the
crown-of-thorns starfish on coral reefs.
Empirical results
Tilman and Downing [14] suggest that primary productivity in more diverse
plant communities is more resistant to, and recovers more fully from, a major
drought.

207 plots of prairie grasslands differing in species richness from 1 to 26.

Measured resistance as relative rate of community biomass change from
1986, the year before a drought, to 1988, the peak of the drought.

Drought resistance is an increasing function of community diversity.

Saturates at about 10–15 species.

More diverse communities are more resistant than less diverse
communities, but they don’t have to be very diverse.

Recent results on the relationship between bacterial species diversity and
community respiration (a measure of total microbial activity) show that
there are diminishing returns as the number of species in the bacterial
community increases [1]. The strong diminishing returns associated with
increases in species diversity are likely to be a general feature of
relationships between ecosystem processes and species richness.
In a similar experiment Tilman et al. [1996] found that plant cover is an
increasing function of species richness and lower concentrations of inorganic
soil nitrogen, presumably because of greater nitrogen uptake in more diverse
communities.
10
Experiments of van der Heijden et al., (1998) on mycorrhizal diversity suggest
that plant species composition and community structure are more sensitive to
the present or absence of particular mycorrhizal associates when the diversity
of mycorrhizal fungi is low. Similarly, plant species diversity, nutrient capture,
and productivity are increasing functions of mycorrhizal diversity.
But there are two possible explanations for patterns like these:
1. More diverse communities could increase the chances that at least one
species within them is highly productive.
2. More diverse communities may be able to tap resources more effectively
because the differ in strategies for resource acquisition.
Cardinale et al. [2006] perform a meta-analysis of 111 field, greenhouse, and
laboratory studies that manipulated species diversity to determine its effect on
abundance and biomass. They found that

Decreasing diversity is, on average,
abundance, decreased biomass, or both.

The standing biomass of the richest polyculture tends to be no different
from that of the most productive monoculture.
associated
with
decreased
“Collectively [their] analyses suggest that the average species loss does
indeed affect the functioning of a wide variety of organisms and ecosystems,
but the magnitude of these effects is ultimately determined by the identity of
species that are going extinct”. Using a somewhat different approach Grace et
al. reach a similar conclusion: “[T]he influence of small-scale diversity on
productivity in natural systems is a weak force, both in absolute terms and
relative to the effects of other controls on productivity”.
5.3.2 FUNCTIONAL DIVERSITY
Diaz and Cabido [2001] point out that experiment like those just described
focus only on the number of species present, not on the functions, they play in
an ecosystem. They summarize evidence from a variety of studies suggesting
that ecosystem processes depend on functional diversity far more strongly
than on species diversity per se. They suggest two plausible explanations:
11
Functional redundancy
Two or more species in a particular ecosystem may play essentially the same
role in ecosystem processes. It may for example, make relatively little
difference to the nitrogen dynamics which particular species of legumes are
present, only that there are some nitrogen-fixing plants present. The loss of
species with similar functional effects should have relatively little effect on
ecosystem processes.
Functional insurance
The more divergent species in an ecosystem are with respect to their
influence on ecosystem processes, the smaller the number required to buffer
an ecosystem against change. Species with similar functional effects that
differ in functional response may buffer ecosystems against externally
imposed change because the species that influence each ecosystem
response may respond differently.
5.3.3 CONCEPTS OF STABILITY
Part of the problem here is that it’s not entirely clear what we mean by
stability, nor what aspect of diversity we are considering.

Are we concerned only with the number of species in the community and
its relation to stability, are we concerned with how evenness relates to
stability, or are we concerned with some combination of both? Work I am
aware of that considers the problem focuses only on species diversity, i.e.,
the number of species present, and only recently has begun to consider
the degree of functional diversity represented.
–
In one sense this may be legitimate. After all, part of the reason
conservationists have invoked the diversity-stability hypothesis is to
justify concern about the loss of individual species.
–
We may also be missing something important. If other aspects
diversity play an important role in the structure and function
ecosystems, a focus on the number of species alone may blind us
the role that evenness plays in the ability of ecosystems to respond
changes in energy and nutrient inputs.
of
of
to
to
12

Various meanings depending on context. There are at least three ways in
which stability might be defined.
1. Lack of change
2. Ability to return quickly to a previous state
3. Not going extinct
Some ecologists use more specific terms :
1. Constancy
“Tendency of an ecosystem to maintain homeostasis (i.e. remain constant
over time)” Homeostasis = equilibrium. This is the definition most people
use when talking about ecological “stability” i.e. remains at equilibrium.
What remains at equilibrium? Examples: No long-term loss of:

Biomass production

Species composition

Population structure

Resources: organic matter, moisture, nutrients, soil characteristics
–
The ability of a community to resist changes in composition and
abundance in response to disturbance. Not a particularly useful
concept of stability for conservationists because.
–
Few, if any, ecosystems could be described as constant.
–
Even
those
that
have
powerful
mechanisms for
reacting
to
environmental fluctuations do so through internal changes that return
the system as quickly as possible to a stable state. But these involve
responses and changes. It seems better to regard them as examples of
resiliency than of constancy.
2. Resilience
The ability of a community to return to a prior state (equilibrium) after
disturbance.

Elasticity : how quickly community returns to equilibrium after
disturbance

Amplitude : how much disturbance community can tolerate and still
return to equilibrium
13

Resistance : the force needed to change the community
–
The ability of a community to return to its pre-disturbance
characteristics after changes induced by a disturbance. Resiliency
corresponds to stability the way it is studied in mathematical models.
Are deviations from equilibrium reduced with time (stable) or amplified
with time (unstable)? Still, it has little applicability to actual ecosystems.
It measures a system’s tendency to return to a single stable point, but
–
Many ecological systems appear to have multiple stable points. If
disturbance remains below a particular threshold, it will return to its
predisturbance configuration. If it exceeds that threshold, it may move
to a new configuration.
–
Furthermore, most ecological systems change not only in response to
disturbance but also in response to natural, successional change.
–
There is little evidence that ecological communities ever represent an
equilibrium configuration from which it would make sense to study
perturbations.
Constancy and resiliency have this in common: both focus on species
persistence and abundance as measures of stability.
3. Persistence
Not going extinct. Usually refers to populations of endangered species, as
in “the population is stable”.
4. Dynamic stability
–
A system is dynamically stable if its future states are determined
largely by its own current state, with little or no reference to outside
influences. In many ways this seems to correspond with our intuitive
notions of stability and to make sense of the relationship between
diversity and stability.
–
Recall the quote from Commoner: “The more complex the ecosystem,
the more successfully it can resist a stress.”
–
A system that is dynamically stable is one that is relatively immune to
disturbance. A rapidly spinning gyroscope is dynamically stable
14
because the gyroscopic forces that it generates resist external forces
that would alter is plane of rotation.
–
It reflects our hope that stable systems should be able to maintain
themselves without human intervention.
–
A diverse biological system is more likely to be dynamically stable than
one that is not diverse because in diverse communities biotic
interactions may often play a larger role in a species’ success than its
interactions with the physical environment. To the extent that changes
in the system are driven by biotic interactions, it is dynamically stable,
since characteristics of the system itself are determining its future
state.
Ives and Carpenter (2007) suggest a different approach to understanding
community stability (Figure 5.1).
–
Alternative stable states
–
Non-point attractors
–
Pulse perturbations
–
Press perturbations
–
Extinctions
–
Invasions
15
Figure 5.1: Types of stability, perturbations, and community responses.
[From Ives and Carpenter (2007)].
Their approach strikes as quite useful, first because it emphasizes that
systems move to a region different from the one from which they were
perturbed and second because it reminds us that things other than diversity,
like the frequency and character of perturbation, may affect the stability of
ecosystems.
Biological integrity
Biological integrity refers to a system’s wholeness, including presence of all
appropriate elements and occurrence of all processes at appropriate rates.
16
1. What are “appropriate elements”?
2. What are “appropriate rates” of processes?
By definition, naturally evolved assemblages possess integrity but random
assemblages do not. Therefore, provides justification for management
focusing on native species rather than introduced ones. This seems like the
logical fallacy of affirming the consequent, but
5.4
–
Species composition of lakes exposed to nutrient enrichment or
acidification responds more quickly and recovers more slowly than
processes like primary production, respiration, and nutrient cycling.
–
Shifts in biotic composition do not necessarily lead to changes in process
rates.
–
Angermeier and Karr suggest that these observations means a focus on
integrity rather than diversity makes sense. To me it makes more sense to
conclude that species changes are a more sensitive indicator of what is
going on than process changes.
–
Loss of native species from a system is truly “a canary in the mine,” a
warning of process changes that may have consequences much larger
than we suspect.
ECOLOGY OF PLANT INVASION
With increased trade and travel, invasions by introduced vascular plants are
becoming commonplace and are widely recognized as one of the most
serious threats to biodiversity and to economies. Introduced plants can have
wide-ranging negative effects on ecosystems. These include alterations to the
physical structure of habitats, nutrient cycling, fertility and productivity,
hydrological regimes, and food webs. All of these alterations would likely
negatively impact local subsistence economies greatly. However, not all
introduced plants are serious threats. Roughly 1% of species that become
established in natural areas become a serious problem. Therefore,
understanding of patterns of species richness is important to predict and limit
plant invasions.
5.4.1 DEFINITIONS
17
Invasive species is a phrase with several definitions. The first definition
expresses the phrase in terms of non-indigenous species (e.g. plants or
animals) that adversely affect the habitats they invade economically,
environmentally or ecologically. It has been used in this sense by government
organizations as well as conservation groups such as the IUCN (International
Union for Conservation of Nature).
The second definition broadens the boundaries to include both native and
non-native species that heavily colonize a particular habitat. The third
definition is an expansion of the first and defines an invasive species as a
widespread non-indigenous species. This last definition is arguably too broad
as not all non-indigenous species necessarily have an adverse effect on their
adopted environment. An example of this broader use would include the claim
that the common goldfish (Carassius auratus) is invasive. Although it is
common outside its range globally, it almost never appears in harmful
densities.
Because of the ambiguity of its definition, the phrase invasive species is often
criticized as an imprecise term within the field of ecology. This article
concerns the first two definitions; for the third, see introduced species.
Stages : In an attempt to avoid the ambiguous, subjective, and pejorative
vocabulary that so often accompanies discussion of invasive species even in
scientific papers, Colautti and MacIsaac have proposed a new nomenclature
system based on biogeography rather than on taxa.
Stage
Characteristic
0
Propagules residing in a donor region
I
Traveling
II
Introduced
III
Localized and numerically rare
IVa
Widespread but rare
IVb
Localized but dominant
V
Widespread and dominant
18
By removing taxonomy, human health, and economic factors from
consideration, this model focuses only on ecological factors. The model
evaluates individual populations, and not entire species. This model does not
attribute detrimentally to invasive species and beneficially to native species. It
merely classifies a species in a particular location based on its growth
patterns in that particular microenvironment. This model could be applied
equally to indigenous and to non-native species.
5.4.2 CONDITIONS THAT LEAD TO INVASION
Scientists propose several mechanisms to explain invasive species, including
species-based mechanisms and ecosystem-based mechanisms. It is most
likely a combination of several mechanisms that cause an invasive situation to
occur, since most introduced plants and animals do not become invasive.
Species-based mechanisms
Species-based characteristics focus on competition. While all species
compete to survive, invasive species appear to have specific traits or
combinations of specific traits that allow them to outcompete native species.
Sometimes they just have the ability to grow and reproduce more rapidly than
native species; other times it's more complex, involving a multiplex of traits
and interactions.
Studies seem to indicate that certain traits mark a species as potentially
invasive. One study found that of a list of invasive and noninvasive species,
86% of the invasive species could be identified from the traits alone. Another
study found that invasive species tended only to have a small subset of the
invasive traits and that many of these invasive traits were found in noninvasive species as well indicating that invasiveness involves complex
interaction not easily categorized. Common invasive species traits include:

The ability to reproduce both asexually as well as sexually

Fast growth

Rapid reproduction

High dispersal ability
19

Phenotypic plasticity (the ability to alter one’s growth form to suit current
conditions)

Tolerance of a wide range of environmental conditions (generalist)

Ability to live off of a wide range of food types (generalist)

Association with humans

Other successful invasions
Typically an introduced species must survive at low population densities
before it becomes invasive in a new location. At low population densities, it
can be difficult for the introduced species to reproduce and maintain itself in a
new location, so a species might be transported to a location a number of
times before it become established. Repeated patterns of human movement
from one location to another, such as ships sailing to and from ports or cars
driving up and down highways, allow for species to have multiple
opportunities for establishment (also known as a high propagule pressure).
An introduced species might become invasive if it can out-compete native
species for resources such as nutrients, light, physical space, water or food. If
these species evolved under great competition or predation, the new
environment may allow them to proliferate quickly. Ecosystems in which all
available resources are being used to their fullest capacity by native species
can be modeled as zero-sum systems, where any gain for the invader is a
loss for the native. However, such unilateral competitive superiority (and
extinction of native species with increased populations of the invader) is not
the rule. Invasive species often coexist with native species for an extended
time, and gradually the superior competitive ability of an invasive species
becomes apparent as its population grows larger and denser and it adapts to
its new location.
An invasive species might be able to use resources previously unavailable to
native species, such as deep water sources accessed by a long taproot, or an
ability to live on previously uninhabited soil types. For example, Barbed
Goatgrass (Aegilops triuncialis) was introduced to California on serpentine
soils, which have low water-retention, low nutrient levels, a high Mg/Ca ratio,
and possible heavy metal toxicity. Plant populations on these soils tend to
show low density, but goatgrass can form dense stands on these soils
crowding out native species that have not adapted well to growing on
serpentine soils.
20
Facilitation is the mechanism by which some species can alter their
environment using chemicals or manipulating abiotic factors, allowing the
species to thrive while making the environment less favorable to other species
with which it competes. One such facilitative mechanism is allelopathy, also
known as chemical competition or interference competition. In allelopathy a
plant will secrete chemicals which make the surrounding soil uninhabitable, or
at least inhibitory, to competing species.
One example of this is the knapweed Centaurea diffusa. This Eastern
European weed has spread its way through the western United States.
Experiments show that 8-Hydroxyquinoline, a chemical produced at the root
of C. diffusa, has a negative effect only on plants that have not co-evolved
with C. diffusa. Such co-evolved native plants have also evolved defenses,
and C. diffusa does not appear in its native habitat to be an overwhelmingly
successful competitor. This shows how difficult it can be to predict if a species
will be invasive just from looking at its behavior in its native habitat, and
demonstrates the potential for novel weapons to aid in invasiveness.
Changes in fire regimes are another form of facilitation. Bromus tectorum,
originally from Eurasia, is highly fire-adapted. It not only spreads rapidly after
burning, but actually increases the frequency and intensity (heat) of fires, by
providing large amounts of dry detritus during the dry fire season in western
North America. In areas where it is widespread, it has altered the local fire
regime so much that native plants cannot survive the frequent fires, allowing
B. tectorum to further extend and maintain dominance in its introduced range.
Facilitation also occurs when one species physically modifies a habitat and
that modification is advantageous to other species. For example, zebra
mussels increase habitat complexity on lake floors providing crevases in
which invertebrates live. This increase in complexity, together with the
nutrition provided by the waste products of mussel filter-feeding increases the
density and diversity of benthic invertebrate communities.
Ecosystem-based mechanisms
In ecosystems, the amount of available resources and the extent to which
those resources are utilized by organisms determines the effects of additional
species on the ecosystem. In stable ecosystems, equilibrium exists in the
21
utilization of available resources. These mechanisms describe a situation in
which the ecosystem has suffered a disturbance which changes the
fundamental nature of the ecosystem. When changes occur in an ecosystem,
like forest fires in an area, normal succession would favor certain native
grasses and forbs. With the introduction of a species that can multiply and
spread faster than the native species, the balance is changed and the
resources that would have been used by the native species are now utilized
by an invader. This impacts the ecosystem and changes its composition of
organisms and their use of available resources. Nitrogen and phosphorus are
often the limiting factors in these situations.
Every species has a role to play in its native ecosystem; some species fill
large and varied roles while others are highly specialized. These roles are
known as niches. Some invading species are able to fill niches that are not
utilized by native species, and they also can create niches that did not exist.
When changes occur to ecosystems, conditions change that impact the
dynamics of species interaction and niche development. This can cause once
rare species to replace other species, because they now can utilize greater
available resources that did not exist before, an example would be the edge
effect. The changes can favor the expansion of a species that would not have
been able to colonize areas and niches that did not exist before.
5.4.3 ECOLOGY OF INVASION
Although an invasive species is often defined as an introduced species that
has spread widely and causes harm, some species native to a particular area
can, under the influence of natural events such as long-term rainfall changes
or human modifications to the habitat, increase in numbers and become
invasive.
All species go through changes in population numbers, in many cases
accompanied by expansion or contraction of range. Human landscape
alterations are especially significant. This anthropogenic alteration of an
environment may enable the expansion of a species into a geographical area
where it had not been seen before and thus that species could be described
as invasive. In essence, one must define "native" with care, as it refers to
some natural geographic range of a species, and is not coincident with human
political boundaries. Whether noticed increases in population numbers and
22
expanding geographical ranges is sufficient reason to regard a native species
as "invasive" requires a broad definition of the term but some native species in
disrupted ecosystems can spread widely and cause harm and in that sense
become invasive. For example, the Monterey Cypress is an endangered
endemic naturally occurring only in two small stands in California. They are
being exterminated as exotic invasive species less than 50 miles (80 km) from
their native home.
Traits of invaded ecosystems
In 1958, Charles S. Elton argued that ecosystems with higher species
diversity were less subject to invasive species because of fewer available
niches. Since then, other ecologists have pointed to highly diverse, but heavily
invaded ecosystems and have argued that ecosystems with high species
diversity seem to be more susceptible to invasion. This debate seems largely
to hinge on the spatial scale at which invasion studies are performed, and the
issue of how diversity affects community susceptibility to invasion remains
unresolved. Small-scale studies tend to show a negative relationship between
diversity and invasion, while large-scale studies tend to show a positive
relationship. The latter result may be an artifact of invasive or non-native
species capitalizing on increased resource availability and weaker overall
species interactions that are more common when larger samples are
considered.
Invasion is more likely if an ecosystem is similar to the one in which the
potential invader evolved. Island ecosystems may be prone to invasion
because their species are “naïve” and have faced few strong competitors and
predators throughout their existence, or because their distance from
colonizing species populations makes them more likely to have “open” niches.
An example of this phenomenon is the decimation of the native bird
populations on Guam by the invasive brown tree snake. Alternately, invaded
ecosystems may lack the natural competitors and predators that keep
introduced species in check in their native ecosystems, a point that is also
seen in the Guam example. Lastly, invaded ecosystems have often
experienced disturbance, usually human-induced. This disturbance may give
invasive species, which are not otherwise co-evolved with the ecosystem, a
chance to establish themselves with less competition from more adapted
species.
23
Vectors
Non-native species have many vectors, including many biogenic ones, but
most species considered "invasive" are associated with human activity.
Natural range extensions are common in many species, but the rate and
magnitude of human-mediated extensions in these species tend to be much
larger than natural extensions, and the distances that species can travel to
colonize are also often much greater with human agency.
One of the earliest human influenced introductions involves prehistoric
humans introducing the Pacific rat (Rattus exulans) to Polynesia. Today, nonnative species come from horticultural plants either in the form of the plants
themselves or animals and seeds carried with them, and from animals and
plants released through the pet trade. Invasive species also come from
organisms stowed away on every type of transport vehicle. For example,
ballast water taken up at sea and released in port is a major source of exotic
marine life. The invasive freshwater zebra mussels, native to the Black,
Caspian and Azov seas, were probably transported to the Great Lakes via
ballast water from a transoceanic vessel. The arrival of invasive propagules to
a new site is a function of the site's invasibility.
Species have also been introduced intentionally. For example, to feel more "at
home", American colonists formed "Acclimation Societies" that repeatedly
released birds that were native to Europe until they finally established along
the east coast of North America.
Economics play a major role in exotic species introduction. The scarcity and
demand for the valuable Chinese mitten crab is one explanation for the
possible intentional release of the species in foreign waters.
5.4.4 IMPACT OF INVASION
Ecological impacts
Biological species invasions alter ecosystems in a multitude of ways.
Worldwide, an estimated 80% of endangered species could suffer losses by
competition with, or predation by, invasive species. Pimentel also reports that
introduced species, such as corn, wheat, rice, cattle, and poultry, provide
more than 98% of the U.S. food system at a value of approximately
24
$800 billion per year. As highly adaptable and generalized species are
introduced to environments already impacted by human activities, some
native species may be put at a disadvantage to survive while other species
survival is enhanced.
Land clearing and human habitation put significant pressure on local species.
This disturbed habitat is prone to invasions that can have adverse effects on
local ecosystems, changing ecosystem functions. A species of wetland plant
known as ʻaeae in Hawaii (the indigenous Bacopa monnieri) is regarded as a
pest species in artificially manipulated water bird refuges because it quickly
covers shallow mudflats established for endangered Hawaiian stilt
(Himantopus mexicanus knudseni), making these undesirable feeding areas
for the birds.
Multiple successive introductions of different nonnative species can have
interactive effects; the introduction of a second non-native species can enable
the first invasive species to flourish. Examples of this are the introductions of
the amethyst gem clam (Gemma gemma) and the European green crab
(Carcinus maenas). The gem clam was introduced into California's Bodega
Harbor from the East Coast of the United States a century ago. It had been
found in small quantities in the harbor but had never displaced the native clam
species (Nutricola spp.). In the mid 1990s, the introduction of the European
green crab, found to prey preferentially on the native clams, resulted in a
decline of the native clams and an increase of the introduced clam
populations.
In the Waterberg region of South Africa, cattle grazing over the past six
centuries has allowed invasive scrub and small trees to displace much of the
original grassland, resulting in a massive reduction in forage for native bovids
and other grazers. Since the 1970s large scale efforts have been underway to
reduce invasive species; partial success has led to re-establishment of many
species that had dwindled or left the region. Examples of these species are
giraffe, Blue Wildebeest, impala, kudu and White Rhino.
Invasive species can change the functions of ecosystems. For example
invasive plants can alter the fire regime (cheatgrass, Bromus tectorum),
nutrient cycling (smooth cordgrass Spartina alterniflora), and hydrology
(Tamarix) in native ecosystems. Invasive species that are closely related with
rare native species have the potential to hybridize with the native species.
25
Harmful effects of hybridization have led to a decline and even extinction of
native species. For example, hybridization with introduced cordgrass, Spartina
alterniflora, threatens the existence of California cordgrass (Spartina foliosa)
in San Francisco Bay.
Genetic pollution
Natural, wild species can be threatened with extinction through the process of
genetic pollution. Genetic pollution is uncontrolled hybridization and
introgression which leads to homogenization or replacement of local
genotypes as a result of either a numerical or fitness advantage of the
introduced species. Genetic pollution can bring about a form of extinction
either through purposeful introduction or through habitat modification, bringing
previously isolated species into contact. These phenomena can be especially
detrimental for rare species coming into contact with more abundant ones
where the abundant ones can interbreed with them, creating hybrids and
swamping the entire rarer gene pool, thus driving the native species to
extinction. Attention has to be focused on the extent of this problem, it is not
always apparent from morphological observations alone. Some degree of
gene flow may be a normal, evolutionarily constructive process, and all
constellations of genes and genotypes cannot be preserved. However,
hybridization with or without introgression may, nevertheless, threaten a rare
species' existence.
Economic impacts
Benefits
Often overlooked, economic benefits from so-called "invasive" species should
also be accounted. The wide range of benefits from many "invasives" is both
well-documented and under-reported. Asian oysters, for example, are better
at filtering out water pollutants than native oysters. They also grow faster and
withstand disease better than natives. Biologists are currently considering
releasing the mollusk in the Chesapeake Bay to help restore oyster stocks
and clean up the bay's pollution. A recent study by the Johns Hopkins School
of Public Health found the Asian oyster could significantly benefit the bay's
deteriorating water quality.
26
Non-native species can become such a common part of an environment,
culture, and even diet that little thought is given to their geographic origin. For
example, soybeans, kiwi fruit, wheat and all livestock except the llama and the
turkey are non-native species to North America. Collectively, non-native crops
and livestock comprise 98% of US food. These and other benefits from nonnatives are so vast that, according to the Congressional Research Service,
they probably exceed the costs.
Costs
Economic costs from invasive species can be separated into direct costs
through production loss in agriculture and forestry, and management costs of
invasive species. Estimated damage and control cost of invasive species in
the U.S. alone amount to more than $138 billion annually. In addition to these
costs, economic losses can occur through loss of recreational and tourism
revenues. Economic costs of invasions, when calculated as production loss
and management costs, are low because they do not usually consider
environmental damages. If monetary values could be assigned to the
extinction of species, loss in biodiversity, and loss of ecosystem services,
costs from impacts of invasive species would drastically increase. The
following examples from different sectors of the economy demonstrate the
impact of biological invasions.
Agriculture
Weeds cause an overall reduction in yield, though they often provide essential
nutrients for subsistence farmers. Weeds can have other useful purposes:
some deep-rooted weeds can "mine" nutrients from the subsoil and bring
them to the topsoil, while others provide habitat for beneficial insects and/or
provide alternative foods for pest species. Many weed species are accidental
introductions with crop seeds and imported plant material. Many introduced
weeds in pastures compete with native forage plants, are toxic (e.g., Leafy
Spurge, Euphorbia esula) to young cattle (older animals will avoid them) or
non-palatable because of thorns and spines (e.g., Yellow Starthistle,
Centaurea solstitialis). Forage loss from invasive weeds on pastures amounts
to nearly $1 billion in the U.S. alone. A decline in pollinator services and loss
of fruit production has been observed to cause the infection of honey bees
(Apis mellifera another invasive species to the Americas) by the invasive
27
varroa mite. Introduced rodents (rats, Rattus rattus and R. norvegicus) have
become serious pests on farms destroying stored grains.
In many cases, one could consider the over-abundant invasive plant species
as a ready source of biomass in the perspective of biogas production.
Forestry
The unintentional introduction of forest pest species and plant pathogens can
change forest ecology and negatively impact timber industry. The Asian longhorned beetle (Anoplophora glabripennis) was first introduced into the U.S. in
1996 and is expected to infect and damage millions of acres of hardwood
trees. Thirty million dollars have already been spent in attempts to eradicate
this pest and protect millions of trees in the affected regions.
The woolly adelgid inflicts damage on old growth spruce fir forests and
negatively impacts the Christmas tree industry. The chestnut blight fungus
(Cryphonectria parasitica) and Dutch elm disease (Ophiostoma novo-ulmi) are
two plant pathogens with serious impacts on forest health.
Tourism and recreation
Invasive species can have impacts on recreational activities such as fishing,
hunting, hiking, wildlife viewing, and water-based recreation. They negatively
affect a wide array of environmental attributes that are important to support
recreation, including but not limited to water quality and quantity, plant and
animal diversity, and species abundance. Eiswerth goes on to say that "very
little research has been performed to estimate the corresponding economic
losses at spatial scales such as regions, states, and watersheds." Eurasian
Watermilfoil (Myriophyllum spicatum) in parts of the US, fill lakes with plants
making fishing and boating difficult.
Health impacts
An increasing threat of exotic diseases exists because of increased
transportation and encroachment of humans into previously remote
ecosystems. This can lead to new associations between a disease and a
human host (e.g., AIDS virus). Introduced birds (e.g. pigeons), rodents and
insects (e.g. mosquitoes, fleas, lice and tsetse fly) can serve as vectors and
28
reservoirs of human diseases. The introduced Chinese mitten crabs are
carriers of the Asian lung fluke. Throughout recorded history epidemics of
human diseases such as malaria, yellow fever, typhus, and bubonic plague
have been associated with these vectors. A recent example of an introduced
disease is the spread of the West Nile virus across North America resulting in
the deaths of humans, birds, mammals, and reptiles. Waterborne disease
agents, such as Cholera bacteria (Vibrio cholerae), and causative agents of
harmful algal blooms are often transported via ballast water. The full range of
impacts of invasive species and their control goes beyond immediate effects
and can have long term public health implications. For instance, pesticides
applied to treat a particular pest species could pollute soil and surface water.
5.4.5 THREAT TO GLOBAL BIODIVERSITY
Biotic invasion is one of the five top drivers for global biodiversity loss and is
increasing because of tourism and globalization. It poses a particular risk to
inadequately regulated fresh water systems, though quarantines and ballast
water rules have improved the situation.
5.5
ENVIRONMENTAL IMPACT ASSESSMENT
Environmental Impact Assessment (EIA) is an important management tool for
ensuring optimal use of natural resources for sustainable development. A
beginning in this direction was made in our country with the impact
assessment of river valley projects in 1978-79 and the scope has
subsequently been enhanced to cover other developmental sectors such as
industries, thermal power projects, mining schemes etc. To facilitate collection
of environmental data and preparation of management plans, guidelines have
been evolved and circulated to the concerned Central and State Government
Departments. EIA has now been made mandatory under the Environmental
(Protection Act, 1986 for 29 categories of developmental activities involving
investments of Rs. 50 crores and above.
Environmental Impact Assessment (EIA) is a relatively new planning and
decision making tool first enshrined in the United States in the National
Environmental Policy Act of 1969. It is a formal study process used to predict
the environmental consequences of any development project. EIA thus
29
ensures that the potential problems are foreseen and addressed at an early
stage in project planning and design.
Environmental Assessment is taken up in this exercise as a rapid assessment
technique for determining the current status of the environment and identifying
impact of critical activities on environmental parameters. Based on this
analysis we can draw up an Environmental Management Plan that would
ensure impact monitoring and mitigation planning.
Environmental Assessment enables us in carrying out Environmental CostBenefit Analysis of projects at an initial stage. It is thus a pre-cursor to
detailed analysis of environmental impacts, which are taken up only if a need
for the same is established. It gives a view of the actors involved in the
`development-environment linkages. This is required in view of the fact that
the community at large is always at a loss in terms of deterioration of living
environment that accompanies industrial development. Based on
Environmental Assessment, the regulatory measures can be identified and
the roles of concerned agencies defined for achieving more efficient
environmental management.
In view of the fact that development is an ever growing process, its impact on
the environment is also ever increasing, leading to rapid deterioration in
environmental conditions. As such Environmental Assessment provides a
rational approach to sustainable development.
Extensively developed rapid assessment techniques often avoid carrying out
of detailed studies which need more resources in terms of time and money.
This exercise is an attempt in developing an approach to Environmental
Assessment technique, primarily for industrial townships.
5.5.1 ASSESSMENT OF ENVIRONMENT IN INDIA - BACKGROUND
Environmental Impact Assessment (EIA) may be defined as a formal process
used to predict the environmental consequences of any development project.
EIA thus ensures that the potential problems are foreseen and addressed at
an early stage in the projects planning and design.
The phrase `Environmental Impact Assessment comes from Sec. 102 (2) of
the National Environmental Policy Act (NEPA), 1969, USA. Some rudiments
30
of EIA are implicit even in early examples of environmental legislation.
Napoleon in 1910 issued a decree which divided noxious occupations into
categories: those which must be far removed from habitations, those which
may be permitted on the outskirts of towns, and those which can be tolerated
even close to habitations, having regard to the importance of the work and the
importance of the surrounding dwellings.
In India, the environmental action formally started with the participation of late
Smt. Indira Gandhi in the UN Conference on Human Environment in
Stockholm in 1972. A National Committee on Environmental Planning &
Coordination (NCEPC) was established to be the apex body in the
Department of Science and Technology. The term `Environment figured for
the first time in the Fourth Five Year Plan (1969-74) which recorded that
`harmonious development is possible only on the basis of a comprehensive
appraisal of environmental issues. The Tiwari Committee (Committee on
Review of Legislative Measures and Administrative Measures), in its report in
1980, recommended creation of a Department of Environment as a nodal
agency to ensure environmental protection, to carry out environmental impact
studies of proposed development projects, and to have administrative
responsibility for pollution monitoring and control. The department came into
being in 1980 within the Ministry of Science and Technology under the charge
of the then Prime Minister. In 1989 the subjects of wildlife and forestry were
added to the list and a new Ministry of Environment and Forests was created
with the Prime Minister holding its charge. Since its inception the Department
(under the Ministry) has issued various guidelines on EIA for various projects.
EIA, in brief, extrapolates from scientific knowledge to assess the problem
consequences of some human interventions on nature. Although EIA uses the
techniques of science, it differs from ordinary scientific inquiry, because it is
dealing with events which have not yet occurred, may not occur, and whose
chances of occurrence may be changed by the very statement that they may
occur.
Some measures are required to be taken in the future to reduce the
anticipated environmental degradation. Before starting a major project, it is
essential to assess the present environment without the project, and the likely
impact of the project on the environment, when it is completed. Therefore, an
Environment Impact Assessment has to be made before starting a project.
For analysis of environmental impacts, many professions and disciplines have
31
to be involved. Like economic and engineering feasibility studies,
Environmental Impact Assessment is a management tool for officials and
managers who make important decisions about major development projects.
The Environmental Impact Assessment should have the following objectives:
i.
ii.
iii.
iv.
Predict environmental impact of projects
Find ways and means to reduce adverse impacts
Shape project to suit local environment
Present the predictions and options to the decision-makers
The EIA statement should cover brief description of project, brief description
of existing environment, likely impact of project, the mitigation and protection
measures, consideration of alternatives, and summary with conclusions.
5.5.2 ENVIRONMENTAL IMPACT ASSESSMENT : A PROCESS
In essence, EIA is a process, a systematic process that examines the
environmental consequences – positive or negative – of development actions
in advance. Unlike other mechanisms for environmental protection; here, in
EIA, the emphasis is on prevention. After an EIA analysis, the precautionary
and polluter pays principles is to be applied to prevent, limit or require strict
liability or insurance coverage to a project, based on its likely harms. No doubt
planners have traditionally assessed the impacts of developments on the
environment, but invariably not in the systematic, holistic and multidisciplinary
way as required by EIA. The EIA process (or methodology) involves a number
of steps which are briefly described as under :
 Project screening : It narrows the application of EIA to those projects that
may have significant environmental impacts. It is the stage when planners
through a preliminary study decide whether to conduct a comprehensive
environmental impact assessment study or not. As an aid, the World Bank
has placed all the projects in four different categories on the basis of the
potential environmental impacts. Large water resources developmental
projects, highway projects, thermal power projects, petrochemical and
fertilizer projects, mining projects and residential construction projects are
some of the examples for which comprehensive EIA studies have to be
conducted for identifying the significant environmental impacts, particularly
the negative ones. Such projects are screened off right in the beginning of
EIA studies.
32
 Scoping : It is focused primarily on determining/ identifying, at an early
stage, a project’s specific, significant issues and impacts which are to be
addressed/ assessed.
 Consideration of Alternatives : This stage seeks to ensure that the
proponent (or promoter) has also considered other feasible approaches,
including alternative projects locations, scales, processes, layouts,
operating conditions, and the “no action” option.
 Description of the Projects/ Development Action : it seeks a
clarification of the purpose and rationale of the projects, and an
understanding of its various characteristics, such as stages of
development, location and processes.
 Description of the Environmental Baseline : it includes the
establishment of both the present and future state of the environment, in
the absence of the projects, taking into account the changes resulting from
natural events and from other human activities.
 Identification of key Impacts : This step bring together the previous
steps with the aims of ensuring that all the potentially significant
environmental impacts (positive and negative) are identified and taken into
account in the process.
 The prediction of Impacts : this step aims to identify the magnitude and
other dimensions of identified change in the environment with a projects/
activity, by comparison with the situation without that project/ activity.
 Evaluation and Assessment of Significance : this seeks to assess the
relative significance of the predicted impacts to allow a focus on key
adverse impacts.
 Mitigation : it involves the introduction of measures to avoid, reduce,
remedy or compensate for any significant adverse impacts.
 Public Consultation and Participation : it aims to assure the quality,
comprehensiveness and effectiveness of the EIA, as well as to ensure that
the public’s views are adequately taken into consideration in the decisionmaking process.
33
 EIS Presentation : the environmental impact statement (EIS) presentation
is a vital step in the process. If done badly, much good work in the EIA
may be negated.
 Review : it involves a systematic appraisal of the quality of the EIS, as a
contribution to the decision-making process.
 Decision-Making : decision-making on the projects involves a
consideration by the relevant authority of the EIS (including consultation
response) together with other material considerations.
 Post-decision Monitoring : it involves the recording of outcomes
associated with development impacts, after a decision to proceed. It can
contribute to effective projects management.
 Auditing : it follows from monitoring. It can involve comparing actual
outcomes and the effectiveness of mitigation. It provides a vital step in the
EIA learning process.
It is important to note here that, although the steps are outlined in linear
fashion but EIA should be cyclic activity, with feedback and interaction
between various steps/ stages. Further, the steps can and does vary
considerably from country to country depending on the EIA legislation in a
country. Therefore, the order of steps in the EIA process may also vary.
5.5.3 ENVIRONMENTAL
DOCUMENTATION
IMPACT
STATEMENT
:
THE
The environmental impact statement (EIS) is the documentation of the
information and estimates of impacts derived from the various steps/ stages in
the EIA process. An example of the content of an EIS for a project are
provided in Table 5.1 and are discussed as under :
 Non-technical Summary : It is an important element in the
documentation. Since EIA can be complex, therefore the non-technical
summary can help in communication with the various parties involved in
the process.
 Methods Statement : Reflecting the potential complexity of the process, a
methods statement, at the beginning, is provided in the first part of EIS. It
provides an opportunity to clarify some basic information. It may include
34
information, such as who is the project developer, who has produced the
EIS, who has been consulted and how, what methods have been used,
what difficulties have been encountered and what are the limitations of the
EIA?
 Summery Statement of Key Issues : It is provided up-front so as to help
in improving communication as well.
 Monitoring Programme : The details of monitoring programme is either
included along with summery statement of key issues in Part 1 : Methods
and key issues or at the end of the document.
 Background to the Proposed Development : It forms the second part of
the EIS. It covers the early steps/ stages of EIA process, including clear
descriptions of the projects and baseline conditions including the relevant
planning policies and plans.
 Topic Areas of EIA : The Part 3 comprises of the EIS on various topic
areas. Within each of the topic areas of the EIS, there would normally be
discussion of existing conditions, predicted impacts, scope for migration
and residual impacts.
EIA and EIS practice vary from study to study, from country to country, and
best practices are constantly evolving. Currently, several countries are in the
favour of greater emphasis to the socio-economic dimension, public
participation and after-the-decision activity (like monitoring).
Table 5.1 : Example of contents of an EIS for a project.
Content
Page No.
Non Technical Summery
Part I.
Methods and issues
1.
Methods statement
2.
Summary of key issues
3.
Monitoring programme statement
Part II.
Background to the proposed development
4.
Preliminary studies : need, planning, alternatives, site
selection.
5.
Site description/ baseline conditions
6.
Description of proposed development
35
7.
Part III.
Construction activities and programme
Environmental impact assessment – topic area
8.
Land use, landscapes and visual quality
9.
Geology, topography and soils
10.
Hydrology and water quality
11.
Air quality and climate
12.
Ecology : terrestrial and aquatic
13.
Noise
14.
Transportation
15.
Socio-economic
16.
Inter-relationship between effects
5.5.4 PURPOSE OF EIA
EIA is an intrinsic link between economic growth and environment. If a
detailed EIA precedes all developmental activities/ projects, then it will greatly
help in averting subsequent adverse impacts on environment. EIA is a
process with several important purposes, such as – an aid to decisionmaking, an aid to the formulation of development actions, an instrument for
sustainable development and many more. These purposes of EIA are briefly
elaborated as under.
1. An Aid to Decision-Making : for the decision-maker (e.g. local, state or
national authority), EIA provides a systematic examination of the
environmental implications of a proposed activity (policy, plan, program, or
project) and sometimes alternatives, before than other techniques, like
cost-benefit analysis. It is not a substitute associated with a proposed
development action, which should lead to more rational and structured
decision-making. Above all, the most important aspect of EIA process is
that it has the potential to be a basis for negotiation between the project
developer, public interest groups and the planning regulator. This, if taken
up, can lead to an outcome that balances the interests of the development
action and the environment, which is the spirit of EIA.
2. An Aid to the Formulation of Development Actions : No doubt, many
developers see EIA as a costly and time-consuming hurdle in their
activities. But it is not so, EIA can be of great benefit to them because it
can provide them a framework for considering location and design issues
36
and environmental issues in parallel. It can be an aid to the formulation of
development actions, indicating the areas where the project can be
modified to minimize or eliminate altogether the adverse impacts on the
environment. The consideration of the environmental impacts early in the
planning phase of development is beneficial on many counts. It can lead :

To environmentally sensitive development;

To harmonious relations between the developer, the planning authority
and the local community;

To a smoother planning permission process; and

Sometimes, as argued by the developers, to a worthwhile financial
return on the extra expenditure incurred.
O’Riordan (1990) links such concepts of negotiation and redesign to the
current dominant environmental themes of “Green Consumerism” and
“Green Capitalism”. The emergence of a growing demand by consumers
for “Green Goods” that do no harm to environment, plus a growing market
of “Green technologies”, is generating a developer response. In such a
scenario, EIA can be the early indicator to the developer of potential
conflicts. Taking a leaf out of it, the wise developers may use the EIA
process to negotiate “Green Gains” solutions that may eliminate or offset
adverse environmental impacts, reduce local community’s opposition and
avoid costly public inquiries.
3. An Instrument for Sustainable Development : The central role of EIA is that
of a key instrument that can be used to achieve the goal of sustainable
development : “development that ensures that the use of resources and the
environment today does not restrict their use by future generations”. It refers
to economic development that meets the needs of all without leaving future
generations with fewer natural resources than those we enjoy today. The
essence of this form of development is a stable relationship between human
activities and the natural world, which does not diminish the prospects for
future generations to enjoy a quality of life at least as good as our own.
It is widely accepted that achieving sustainable development requires balance
between the economic development, social development and environmental
protection. Therefore, the existing environmentally harmful developments
37
have to be managed as best as they can be. In extreme cases, they may be
closed down, but they can still leave behind residual environmental problems
for decades to come. Is it not better to mitigate the harmful effects in advance,
at the planning stage, or in some cases to avoid the particular development
altogether? There is an old and trusted saying – Prevention is better than
cure. This is what EIA aims at. Therefore, EIA could form a major instrument
to achieve sustainable development, provided the conceptual framework is
extended to the cumulative assessment of developmental policies, plans and
projects on a regional basis.
Check your progress 1
Notes :
a)
Write your answer in the space given below.
b)
Compare your answer with key, given at the end of the unit.
1.
What is environmental impact assessment? Discuss its importance in
Que.
relation with development plans of the country.
2.
What are the main impacts of invasion on environment? How the
environmental status may be evaluated?
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4. Changing perspective on EIA roles : Environmental impact analysis is
sometimes seems to be controversial. The arguments for EIA vary in time,
space and according to the perspective of those involved. From a minimalist
defensive perspective, developers (and possibly some government officials)
might see EIA as obligatory evil, an administrative futile exercise, sometimes
38
to be gone through that might result in some minor, often cosmetic, alterations
to a development that would probably have happened anyway. Even for the
“Deep Ecologists” or “Deep Greens”, EIA cannot provide the 100 % certainty
about the environmental consequences of development proposals; but they
feel that any projects carried out under uncertainty or risky-circumstances
should be abandoned. EIA and its method must straddle such perspectives.
Today, EIA is often seen as a positive process that seeks a harmonious
relationship between development and the environment. But that was not the
case a few decades back. Earlier, in 1970s, EIA was seen as a defensive tool;
however, in 1990s it evolved as a potentially exciting environmental and social
betterment technique. Now, if one sees EIA not so much as a technique,
rather as a process that is constantly changing in the face of changing
environmental politics and managerial capabilities, one can visualize EIA as a
sensitive barometer of environmental values in a complex environmental
society. The nature and use of EIA is bound for further change as the relative
values and perspectives also change.
5.6
ECOSYSTEM RESTORATION
Humans depend greatly on an ecosystem services. An eco /or ecological
systems or services may be defined as a community of plants and animals
interacting with each other and their abiotic, or natural, environment. Typically,
ecosystems are differentiated on the basis of dominant vegetation,
topography, climate, or some other criteria. Boreal forests, for example, are
characterized by the predominance of coniferous trees; prairies are
characterized by the predominance of grasses; the Arctic tundra is
determined partly by the harsh climatic zone. In most areas of the world, the
human community is an important and often dominant component of the
ecosystem.
Ecosystems include not only natural areas (e.g., forests, lakes, marine coastal
systems) but also human-constructed systems (e.g., urban ecosystems, agroecosystems, impoundments). Human populations are increasingly
concentrated in urban ecosystems, and it is estimated that, by the year 2010,
50 percent of the world's population will be living in urban areas.
These ecosystem services vary greatly and include such things as erosion
control, water and air purification, food, recreation, a list that could go on
39
endlessly. To put things into a sharper perspective, at this point in time, we
need ecosystems for our continued survival. There are many reasons to
restore ecosystems, some include :
1. Restoring natural capital (i.e. goods and services);
2. Mitigating climate change (e.g. through carbon sequestration);
3. Helping threatened or endangered species recover, and
4. Aesthetic reason.
There are also moral reasons to restore ecosystems. Some would say that we
have degraded, and in some cases destroyed, many ecosystems so it falls on
us to ‘fix’ them.
There is also the dissenting opinion that ecosystem restoration is not a
valuable use of our time. Reasons for this opinion can include :
1.
2.
3.
4.
Restorations are not economically feasible;
They don’t always work;
They are expensive (money could be put to better uses); and that
Ecosystems naturally change over time and can recover by themselves.
The problem is that we cannot restore an ecosystem to the exact same state
it was in before we disturbed it. This is because, as Anthony Bradshaw
claims, “ecosystems are not static, but in a state of dynamic equilibrium….
[with restoration] we aim [for a] moving target.”
Even though an ecosystem may not be in its original state, the functions of the
ecosystem (especially ones that provide services to us) may be more valuable
than its configuration. One reason to consider ecosystem restoration is to
mitigate climate change through activities such as afforestation. Afforestation
involves replanting forests, which remove carbon dioxide from the air. Carbon
dioxide is a leading cause of global warming and capturing it would help
alleviate climate change.
5.6.1 ECOSYSTEM HEALTH
40
It is important to recognize the inherent difficulties in defining "health," whether
at the level of the individual, population, or ecosystem. The concept of health
is somewhat of an enigma, being easier to define in its absence (sickness)
than in its presence. Perhaps partially for that reason, ecologists have
resisted applying the notion of "health" to ecosystems. Yet, ecosystems can
become dysfunctional, particularly under chronic stress from human activity.
For example, the discharge of nutrients from sewage, industrial waste, or
agricultural runoff into lakes or rivers affects the normal functioning of the
ecosystem, and can result in severe impairment. Unfortunately, degraded
ecosystems are becoming more the rule than the exception.
The study of the features of degraded systems, and comparisons with
systems that have not been altered by human activity, makes it possible to
identify the characteristics of healthy ecosystems. Healthy ecosystems may
be characterized not only by the absence of signs of pathology, but also by
signs of health, including measures of vigor (productivity), organization, and
resilience.
Vigor can be assessed in terms of the metabolism (activity and productivity) of
the system. Ecosystems differ greatly in their normal ranges of productivity.
Estuaries are far more productive than open oceans, and marshes have
higher productivity than deserts. Health is not evaluated by applying one
standard to all systems. Organization can be assessed by the structure of the
biotic community that forms an ecosystem and by the nature of the
interactions between the species (both plants and animals). Invariably,
healthy ecosystems have more diversity of biota than ecologically
compromised systems. Resilience is the capacity of an ecosystem to maintain
its structure and functions in the face of natural disturbances. Systems with a
history of chronic stress are less likely to recover from normal perturbations
such as drought than those systems that have been relatively less stressed.
]
Healthy ecosystems can also be characterized in economic, social, and
human health terms. Healthy ecosystems support a certain level of economic
activity. This is not to say that the ecosystem is necessarily self-sufficient, but
rather that it supports economic productivity to enable the human community
to meet reasonable needs. Inevitably, ecosystem degradation impinges on the
long-term sustainability of the human economy that is associated with it,
although in the short-term this may not be evident, as natural capital (e.g.,
soils, renewable resources) may be overexploited and temporarily enhance
41
economic returns. Similarly, with respect to social well-being, healthy
ecosystems provide a basis for and encourage community integration.
Historically, for example, native Hawaiian groups managed their ecosystem
through a well-developed social cohesiveness that provided a high degree of
cooperation in fishing and farming activity.
Another reflection of ecosystem health lies directly in the public health
domain. In spring 2000, a deadly strain of the bacterium E-coli (0157:H7)
entered the public water supply in Walkerton, Ontario, Canada, causing seven
deaths and making thousands sick. This small town, with a population of five
thousand, is in a farming community. Inadequate manure management from
cattle operations was the likely source of this tragedy.
5.6.2 HOW HEALTHY ECOSYSTEMS BECOME PATHOLOGICAL
Stress from human activity is a major factor in transforming healthy
ecosystems to sick ecosystems. Chronic stress from human activity differs
from natural disturbances. Natural disturbances (fires, floods, periodic insect
infestations) are part of the dynamics of most ecosystems. These processes
help to "reset" ecosystems by recycling nutrients and clearing space for
recolonization by biota that may be better adapted to changing environments.
Thus, natural perturbations help keep ecosystems healthy. In contrast,
chronic and acute stress on ecosystems resulting from human activity (e.g.,
construction of large dams, release of nutrients and toxic substances into the
air, water, and land) generally results in long-term ecological dysfunction.
Five major sources of human-induced (anthropogenic) stresses have been
identified by D. J. Rapport and A. M. Friend (1979):
1. Physical restructuring,
2. Over harvesting,
3. Waste residuals,
4. Introduction of exotic species, and
5. Global change.
42
1. Physical Restructuring : Activities such as wetland drainage, removal of
shoals in lakes, damming of rivers, and road construction fragment the
landscape and alter and damage critical habitat. These activities also
disrupt nutrient cycling, and cause the loss of biodiversity.
2. Over harvesting : Overexploitation is commonplace when it comes to
harvesting of wildlife, fisheries, and forests. Over long periods of time,
stocks of preferred species are reduced. For example, the giant redwoods
that once thrived along the California coast now exist only in remnant
patches because of overharvesting. When dominant species like the giant
redwoods (arguably the world's tallest tree—one specimen was recorded
at 110 meters tall with a circumference of 13.4 meters) are lost, the entire
ecosystem becomes transformed. Overharvesting often results in reduced
biodiversity of endemic species, while facilitating the invasion of
opportunistic species.
3. Waste Residuals : Discharges from municipal, industrial, and agricultural
sources into the air, water, and land have severely compromised many of
the earth's ecosystems. The effects are particularly apparent in aquatic
ecosystems. In some lakes that lack a natural buffering capacity, acid
precipitation has eliminated most of the fish and other organisms. While
the visual effect appears beneficial (water clarity goes up) the impact on
ecosystem health is devastating. Systems that once contained a variety of
organisms and were highly productive (biologically) become devoid of
most lifeforms except for a few acid-tolerant bacteria and sedimentdwelling organisms.
4. Introduction of Exotic Species : The spread of exotics has become a
problem in almost every ecosystem of the world. Transporting species
from their native habitat to entirely new ecosystems can wreck havoc, as
the new environments are often without natural checks and balances for
the new species. In the Great Lakes Basin, the accidental introduction of
two small pelagic fishes, the alewife and the rainbow smelt, combined with
the simultaneous over harvesting of natural predators, such as the lake
trout, led to a significant decline in native fish species. The introduction of
the sea lamprey, an eel-like predacious fish that attacks larger fish, into
Lake Erie and the upper Great Lakes further destabilized the native fish
community. The sea lamprey contributed to the demise of the deepwater
benthic fish community by preying on lake trout, whitefish, and burbot. This
contributed to a shift in the fish community from one that had been
43
dominated by large benthic to one dominated by small pelagic (fish found
in the upper layers of the lake profile). This shift from bottom-dwelling fish
(benthic) to surface-dwelling fish (pelagic) has now been partially reversed
by yet another accidental introduction of an exotic: the zebra mussel. As
the zebra mussel is a highly efficient filter of both phytoplankton and
zooplankton, its presence has reduced the available food in the surface
waters for pelagic fish.
However, while the benthic fish community has gained back its
dominance, the preferred benthic fish species have not yet recovered
owing to the degree of initial degradation. Overall, the increasing
dominance by exotics not only altered the ecology, but also reduced
significantly the commercial value of the fisheries.
5. Global Change : Rapid climate change (or climate warming) is an
emerging potential global stress on all of the earth's ecosystems. In
evolutionary time, there have of course been large fluctuations in climate.
However, for the most part these fluctuations have occurred gradually over
long periods of time. Rapid climate change is an entirely different matter.
By altering both averages and extremes in precipitation, temperature, and
storm events, and by destabilizing the El Niño Southern Oscillation
(ENSO), which controls weather patterns over much of the southern
Pacific region, many ecosystem processes can become significantly
altered. Excessive periods of drought or unusually heavy rains and
flooding will exceed the tolerance for many species, thus changing the
biotic composition. Flooding and unusually high winds contribute to soil
erosion, and at the same time add to nutrient load in rivers and coastal
waters.
These anthropogenic stresses have compromised ecosystem function in most
regions of the world, resulting in ecosystem distress syndrome (EDS). EDS is
characterized by a group of signs, including abnormalities in nutrient cycling,
productivity, species diversity and richness, biotic structure, disease
prevalence, soil fertility, and so on. The consequences of these changes for
human health are not inconsiderable. Impoverished biotic communities are
natural harbors for pathogens that affect humans and other species.
5.6.3 ECOSYSTEM HEALTH AND HUMAN HEALTH
44
An important aspect of ecosystem degradation is the associated increased
risk to human health. Traditionally, the concern has been with contaminants,
particularly industrial chemicals that can have adverse impacts on human
development, neurological functions, reproductive functions, and that appear
to be causative agents in a variety of carcinomas. In addition to these serious
environmental concerns (where the remedies are often technological,
including engineering solutions to reduce the release of contaminants), there
are a large number of other risks to human health stemming from ecological
imbalance.
Ecosystem distress syndrome results in the loss of valued ecosystem
services, including flood control, water quality, air quality, fish and wildlife
diversity, and recreation. One of the major signs of EDS is increased disease
incidence, both in humans and other species. Human population health
should thus be viewed within an ecological context as an expression of the
integrity and health of the life-supporting capacity of the environment.
Ecological imbalances triggered by global climate change and other causes
are responsible for increased human health risks.
Climate Change and Vector-Borne Diseases. The global infectious disease
burden is on the order of several hundred million cases per year. Many
vector-borne diseases are climate sensitive. Malaria, dengue fever, hantavirus
pulmonary syndrome, and various forms of viral encephalitis are all in this
category. All these diseases are the result of arthropod-borne viruses
(arboviruses) which are transmitted to humans as a result of bites from bloodsucking arthropods.
Global climate change—particularly as it impacts both temperatures and
precipitation—is highly correlated with the prevalence of vector-borne
diseases. For example, viruses carried by mosquitoes, ticks, and other bloodsucking arthropods generally have increased transmission rates with rising
temperatures. St. Louis encephalitis (SLE) serves as an example. The
mosquito Culex tarsalis carries this virus. The percentage of bites that results
in transmission of SLE is dependent on temperature, with greater
transmission at higher temperatures.
The temperature dependence of vector-borne diseases is also well illustrated
with malaria. Malaria is endemic throughout the tropics, with a high
45
prevalence in Africa, the Indian subcontinent, Southeast Asia, and parts of
South and Central America and Mexico. Approximately 2.4 billion people live
in areas of risk, with some 350 million new infections occurring annually,
resulting in approximately 2 million deaths, predominantly in young children.
Untreated malaria can become a life-long affliction—general symptoms
include fever, headache, and malaise.
The climate sensitivity of malaria arises owing to the nature of the interactions
of parasites, vectors, and hosts, all of which impact the ultimate transmission
rates to humans. The gestation time required for the parasite to become fully
developed within the mosquito host (a process termed sporogony) is from
eight to thirty-five days. When temperatures are in the range of 20°C to 27°C,
the gestation time is reduced. Rainfall and humidity also have an influence.
Both drought and heavy rains tend to reduce the population of mosquitoes
that serve as vectors for malaria. In drier regions of the tropics, low rainfall
and humidity restricts the survival of mosquitoes. Severe flooding can result in
scouring of rivers and destruction of the breeding habitats for the mosquito
vector, while intermediate rainfall enhances vector production.
Ecological Imbalances. Cholera is a serious and potentially fatal disease
that is caused by the bacterium Vibrio cholerae. While not nearly so prevalent
as malaria, cases are nonetheless numerous. In 1993, there were 296,206
new cases of cholera reported in South America; 9,280 cases were reported
in Mexico; 62,964 cases in Africa; and 64,599 cases in Asia. Most outbreaks
in Asia, Africa, and South America have originated in coastal areas.
Symptoms of cholera include explosive watery diarrhea, vomiting, and
abdominal pain. The most recent pandemic of cholera involved more regions
than at any previous time in the twentieth century. The disease remains
endemic in India, Bangladesh, and Africa. Vibrio cholerae has also been
found in the United States—in the Gulf Coast region of Texas, Louisiana, and
Florida; the Chesapeake Bay area; and the California coast.
The increase in prevalence of V. cholerae has been strongly linked to
degraded coastal marine environments. Nutrient-enriched warmer coastal
waters, resulting from a combination of climate change and the use of
fertilizers, provides an ideal environment for reproduction and dissemination
of V. cholerae. Recent outbreaks of cholera in Bangladesh, for example, are
closely correlated with higher sea surface temperatures. V. cholerae attach to
the surface of both freshwater and marine copepods (crustaceans), as well as
46
to roots and exposed surfaces of macrophytes (aquatic plants) such as the
water hyacinth, the most abundant aquatic plant in Bangladesh. Nutrient
enrichment and warmer temperatures give rise to algae blooms and an
abundance of macrophytes. The algae blooms provide abundant food for
copepods, and the increasing copepod and macrophyte populations provide
V. cholerae with habitat. Subsequent dispersal of V. cholerae into estuaries
and fresh water bodies allows contact with humans who use these waters for
drinking and bathing. Global distribution of marine pathogens such as V.
cholerae is further facilitated by ballast water discharged from vessels. Ballast
water contains a virtual cocktail of pathogens, including V. cholerae.
Antibiotic Resistance and Agricultural Practice Antibiotic resistance is a
growing threat to public health. Antibiotic resistant strains of Streptococcus
pneumoniae, a common bacterial pathogen in humans and a leading cause of
many infections, including chronic bronchitis, pneumonia, and meningitis,
have greatly increased in prevalence since the mid-1970s. In some regions of
the world, up to 70 percent of bacterial isolates taken from patients proved
resistant to penicillin and other b-lactam antibiotics. The use of large
quantities of antibiotics in agriculture and aquaculture appears to have been a
key factor in the development of antibiotic resistance by pathogens in farm
animals that subsequently may also infect humans. One of the most serious
risks to human health from such practices is vancomycin-resistant
enterococci. The use of avoparcin, an animal growth promoter, appears to
have compromised the utility of vancomycin, the last antibiotic effective
against multi-drug-resistant bacteria. In areas where avoparcin has been
used, such as on farms in Denmark and Germany, vancomycin-resistant
bacteria have been detected in meat sold in supermarkets. Avoparcin was
subsequently banned by the European Union. Another example is the use of
ofloxacin to protect chickens from infection and thereby enhance their growth.
This drug is closely related to ciprofloxacin, one of the most widely used
antibiotics in the year 2000. There have been cases of resistance to
ciprofloxacin directly related to its veterinary use. In the United Kingdom,
ciprofloxacin resistance developed in strains of campylobacter, a common
cause of diarrhea. Multi-drug-resistant strains of salmonella have been traced
to European egg production.
Food and Water Security. Agricultural practices are also responsible for a
growing number of threats to public health. Some of these are related to
inadequate waste management, which has resulted in parasites and bacteria
47
entering water supplies. Others are of entirely different origins and involve
apparent transfer across species of pathogens that affect both animals and
humans. The most recent and spectacular example is mad cow disease,
known as variant Creutzfeldt-Jakob disease in humans, a neuro-degenerative
condition that, in humans, is ultimately fatal. The first case of Bovine
Spongiform Encephalopathy (BSE), the animal form of the disease, was
identified in Southern England in November 1981. By the fall of 2000, an
outbreak had also occurred in France, and isolated cases appeared in
Germany, Switzerland, and Spain. More than one hundred deaths in Europe
were attributed to what has come to be commonly called mad cow disease.
Improper manure management was the likely source of the outbreak of E. coli
0157:H7 in Walkerton, Ontario, Canada. Other health risks associated with
malfunctioning
agroecosystems
include
periodic
outbreaks
of
cryptosporidiosis, a parasitic disease that is spread by surface runoff
contaminated by feces of infected cattle. This parasite causes fever and
diarrhea in immunocompetent individuals and severe diarrhea and even death
in immunocompromised individuals.
5.6.4 ECOSYSTEM RESTORATION
Ecosystem pathology in some cases can be reversed simply by removing the
source of stress. In cases, for example, where ecosystem degradation is the
result of point-source additions of nutrients or toxic chemicals, removal of
these stresses may result in considerable recovery of ecosystem health. A
classic case is Lake Washington (near Seattle, Washington). This lake had
become highly anoxic (oxygen-depleted) owing to a sewage outfall entering
the lake. Redirecting the sewage outfall away from the lake reversed many of
the signs of pathology.
In cases where it is not feasible to remove the source of stress, more
innovative engineering solutions have been tried. For example, in the
Kyrönjoki and Lestijoki Rivers in western Finland, spring and fall runoff leads
to sharp pulses of acidity. Spring runoff from snowmelt, which releases acid
from tilled or dug soils, has been particularly damaging to fish, during the
critical time of year for spawning. Fish reproduction is severely curtailed, if not
all together eliminated in highly acidic water. Further there have been massive
fish kills resulting from the highly acidic waters. One possible remedy is to
replace the original drains which take runoff from the land to the rivers with
48
new limed drains that can neutralize the acidity. This solution has been
implemented on an experimental basis and appears to substantially reduce
acidic runoff.
More radical treatments for damaged ecosystems involve "ecosystem
surgery." In some cases, invading exotic vegetation (such as mangroves in
Hawaii) have been removed from regions, and native vegetation has been
replanted. In areas of North America where wetlands have been severely
depleted owing to farming, urbanization, and industrial activity, efforts have
been made to establish new wetlands.
More often than not, however, reversing ecosystem pathology is not possible.
Efforts to restore the indigenous grasslands in the Jornada Experimental
Range in the southwestern United States provide an example. Overgrazing by
cattle has severely degraded the landscape and has lead to replacement of
the native grasses by largely inedible shrubs, dominated by mesquite. Erosion
by wind and episodic heavy rains have left areas between shrubs largely
bare, and subsequently underlying sands have developed in dune-like fashion
over a large part of the area. The resulting mesquite dunes have proven
highly resistant to efforts to restore the native grasslands, although almost
every intervention has been tried, including highly toxic defoliants (Agent
Orange), fire, and bulldozing.
Even where it has been possible to restore some of the ecological functions of
degraded ecosystems, and thus improve ecosystem health, the restoration
seldom results in reestablishment of the pristine biotic community. The best
that can be achieved in most cases is reestablishment of the key ecological
functions that provide the required ecosystem services, such as the regulation
of water, primary and secondary productivity, nutrient cycling, and pollination.
In all such efforts, key indicators of ecosystem health (vigor, productivity, and
resilience) are essential to monitor progress. Standard ecological indicators
can be used for this purpose (e.g., measures of productivity, species
composition, nutrient flows, soil fertility) along with socioeconomic and human
health indicators.
Experience in efforts to restore highly damaged ecosystems suggests that
ecosystem-health prevention is far more effective than restoration. For marine
ecosystems, setting aside protective zones that afford a sanctuary for fish and
wildlife has considerable promise. Many countries are adopting policies to
49
establish such areas with the prospect that these healthy regions can serve
as a reservoir for biota that have become depleted in the unprotected areas.
Yet this remedy is not without its limits. Restoring ecosystem health is not
simply a matter of replenishing lost or damaged biota. It is also a matter of
reestablishing the complex interactions among ecosystem lifeforms. Having a
ready source of healthy biota that could potentially recolonize damaged
ecosystems is important, but it is only part of the solution.
5.6.5 PROBLEMS WITH RESTORATION
Many people take the view that ecosystem restoration is impractical. One
reason for this view is that restoration of ecosystems does not always work.
There are many reasons for restoration failure. Hilderbrand et al. (2005) point
out that many times uncertainty (about ecosystem functions, species
relationships, and such) is not addressed, and that the time-scales set out for
‘complete’ restoration are unreasonably short. Other times an ecosystem may
be so degraded that abandonment (allowing an injured ecosystem to recover
on its own) may be the wisest option. Other negative impacts of ecosystem
restoration can include the introduction of large predators, which may inspire
doubts in people’s safety, and plants, some requiring disturbance regimes
such as regular fires. High economic costs can also be a perceived as a
negative impact of the restoration process. Public opinion is very important in
the feasibility of a restoration; if the public believes that the costs of
restoration outweigh the benefits, then support for that project is unlikely to be
big, especially in small towns. In these cases people might be ready to follow
the abandonment route and let the ecosystem recover on its own, which can
sometimes occur relatively quickly.
Many failures have occurred in past restoration projects, many times because
clear goals were not set out as the aim of the restoration. This may be
because, as Peter Alpert says, “people may not [always] know how to
manage natural systems effectively”. Also many assumptions are made about
myths of restoration such as the carbon copy, where a restoration plan, which
worked in one area, is applied to another with the same results expected, but
not realized.
5.6.6 PREVENTION OF ECOSYSTEM DISRUPTIONS
50
Given the difficulties in reversing ecosystem degradation, and the many
associated risks that arise with the loss of ecosystem health, the most
effective approach is simply the prevention of ecosystem disruption. However,
like many common-sense approaches, this is easier said than done. In both
developed and developing countries there is a strong inclination to continue
economic growth, even at the cost of severe environmental damage. Apart
from selfish motivations, the argument is made that economic growth has
many obvious health benefits, such as providing more efficient means of
distributing food supplies, providing more plentiful food, and providing better
health services and funding for research to improve standards of living. These
are indeed benefits of economic development, and have led to substantial
increases in health status worldwide.
However, at the dawn of the twenty-first century, the past is not necessarily
the best guide to the future. The human population is at an alltime high, and
associated pressures of human activity have led to increasing degradation of
the earth's ecosystems. As ultimately healthy ecosystems are essential for life
of all biota, including humans, current global and regional trends are ominous.
Under these circumstances, a tradeoff between immediate material gains and
long-term sustainability of humans on the planet may be the only option. If so,
the solution to sustaining human health and ecosystem health becomes one
of devising a new politic that places sustaining life-support systems as a
precondition for betterment of the human condition.
5.7
Ecological Management
5.7.1 ECOLOGICAL MANAGEMENT
The enormous scale of the extinction crisis we are now facing poses daunting
challenges. The number of species threatened with extinction is so vast that it
is virtually impossible to imagine that more than a few of the most important
individual species will receive detailed study. It would seem that our most
realistic hope for preventing extinction on a massive scale is to manage entire
systems to conserve their biodiversity. The idea is that we should manage an
ecosystem and its processes in a way that will protect its structure. Our hope
is that by doing so we will also protect the populations of most or all species
that are part of that ecosystem.
51
In the last ten or fifteen years “ecological management” or “large-scale
conservation” has become the mantra of many conservation organizations,
both public and private. In broad outline the objectives of ecological
management seem clear and unobjectionable:
To maintain hierarchical patterns of biological diversity as well as the
processes and functions supporting the phenomena that spawned them.
Grumbine (1994) suggests that ecological management is based on three
observations:
1. To protect biological diversity the processes that produced it must be
protected as well.
2. Species richness alone is not a good measure of management success.
3. Management must be planned for the long-term, possibly even for the
indefinite future, i.e., ecological management is intended to result in both a
sustainable system and a set of sustainable management activities.
Groom et al. (2005) suggest a slightly different definition, one that explicitly
recognizes the role of social, economic, and institutional factors in ecological
management projects:
An approach to maintaining or restoring the composition, structure, and
function of natural and modified ecologicals for the goal of long-term
ecological and human sustainability. It is based on a collaboratively developed
vision of desired future conditions that integrates ecological, socioeconomic,
and institutional perspectives, applied within a geographic framework defined
primarily by natural ecological boundaries (Figure 5.2).
Before discussing concerns that have been raised about ecological
management, let’s outline the steps in the process that might be followed in
developing an ecological management plan. According to Harwell (1997), the
development of the ecological management plan falls naturally into four
distinct phases:
1. Determining the current status and threats,
2. Identifying the biologically achievable management goals,
3. Characterizing societal factors that influence the choice of management
goals, and
4. Establishing management goals.
52
Figure 5.2 : One way of envisioning the conceptual basis of
ecological management.
5.7.2 CURRENT STATUS AND THREATS
Before you can manage a system you have to know what its characteristics
are. In the case of an ecosystem that means knowing its current status and
the threats it may be facing. That means doing at least two things:
1. Determining the boundaries of the ecosystem to be managed and the
types of habitat within it that are to be managed and
2. Developing a conceptual model of human influences on the ecosystem.
The threats are manifold, and nearly all are related to human pressures.
5.7.3 BIOLOGICALLY ACHIEVABLE MANAGEMENT GOALS
Once you’ve figured out what the system is that you’re trying to protect and
you’ve identified the threats to the system, you have to figure out what
endpoints are biologically achievable. To identify what things are possible it is
necessary to select appropriate measures for the “health” of various
ecological components.
An implicit part of defining biological achievable management goals is that the
goals are sustainable for the indefinite future.
53
5.7.4 SOCIETAL FACTORS
Human and societal influences except to the extent, pose a direct threat to the
species. Conservation initiatives may sometimes be needed at a very broad
scale, and at that very broad scale humans are almost always part of the
system. That means if the system is to be managed sustainably, attention
must be given not only to the needs of non-human organisms in the system
but to those of humans as well.
There are three different ways in which it is necessary to assess societal
factors.
1. The human activities that lead to substantial influences on or domination of
ecosystems must be identified and understood.
2. The legal, economic, institutional, political, and other societal factors that
affect the frequency and scale of those activities must identified and
understood.
3. The values and preferences of relevant interest groups with an influence
on the ecosystem must be characterized.
The last of these items may be the most difficult for many environmentalists to
accept. The list of biologically achievable management goals is likely to
include a range of options from those where large portions of the ecosystem
are substantially free of human influence to those where large portions of the
ecosystem are human-dominated or human-influenced.
5.7.5 ESTABLISHING MANAGEMENT GOALS
With all of that in place, all that is necessary is to “establish ecological
sustainability goals in terms of ecological endpoints and human values.”
If you are a biologist participating in such a process, your expertise will be
particularly important in defining what endpoints are achievable. While
biological expertise is needed to define the range of the possible, choosing
among possible endpoints is a question of values.
54
Biologists have no special competence on this choosing among competing
values. We can describe the consequences of different choices, but we don’t
necessarily have any special standing to choose one set of consequences
over another. In a discussion about choosing among endpoints, what
biologists can do is to make sure that everyone discusses only scenarios that
can be achieved and that everyone understands the tradeoffs among them.
As Harwell et al. (1999) point out, decisions about design and implementation
of an ecological management program lie along a continuum:
1. Societal values will have a dominant role in determining the outcome of
those that are predominantly concerned with defining the management
goals.
2. Scientific expertise will have a dominant role in determining the outcome of
those that are predominantly concerned with measuring how the system
responds.
3.
Societal values and scientific expertise will have equal roles in determining
the system endpoints that will be measured to determine whether
management goals are being achieved.
5.7.6 ADAPTIVE MANAGEMENT
Adaptive management is simply the idea that management actions are like
experiments. They are tests of hypotheses about how the system works. So if
we monitor the results of those tests, we can confirm or reject our hypotheses
and improve our understanding of the system while we manage it. We do not
have to wait until all of the answers are in. We can gather some of them while
we proceed (Figure 5.3).
55
Figure 5.3 : A conceptual diagram of the process of adaptive
management.
5.7.7 A CRITIQUE OF ECOLOGICAL MANAGEMENT
Goldstein (1999) argues that the ecological management not only often fails
to honor those principles, but also that it is largely an attempt to bypass the
requirement for life history information on all species of concern. He goes on
to argue that this attempt is doomed to failure for three reasons:
1. Measures of local species richness can diminish the contribution of
threatened species to priority setting.
2. Good “indicator taxa” don’t exist, i.e., it’s not possible accurately to predict
community properties from the presence or absence of certain taxa.
3. Concepts like ecological integrity, ecosystem function, ecosystem
resilience, ecosystem health, and naturalness don’t provide concrete
guidelines for management.
His objection boils down to this:
56
For management strategies and techniques to be successful at preserving
anything other than perceived structures, functions, and processes of
landscapes, they must be evaluated against the performance of populations
and metapopulations in those managed landscapes, including but not limited
to the most sensitive and threatened species . . . ecological management will
be successful only if ecosystem is used in a sense that can be guaged with
precision and if the criteria used actually reflect the needs of natural entitites
we wish to protect rather than abstracted emergent properties, functions, and
processes of groups of organisms.
5.8
SUSTAINABLE DEVELOPMENT
Considering that the concept of sustainable development is now enshrined on
the masthead of Environment magazine, featured on 8,720,000 Web pages
and enmeshed in the aspirations of countless programs, places, and
institutions, it should be easy to complete the sentence.
The most widely accepted definition is creatively ambiguous : “Humanity has
the ability to make development sustainable—to ensure that it meets the
needs of the present without compromising the ability of future generations to
meet their own needs.”
This malleability allows programs of environment or development; places from
local to global; and institutions of government, civil society, business, and
industry to each project their interests, hopes and aspirations onto the banner
of sustainable development.
A brief history of the concept, along with the interpretive differences and the
common ground in definitions, goals, indicators, values, and practice follows.
Taken together, these help explain what is meant by sustainable
development.
5.8.1 BACKGROUND
In the last half of the twentieth century, four key themes emerged from the collective concerns and aspirations of the world’s peoples: peace, freedom,
development, and environment. The peace that was thought to be secured in
the postwar world of 1945 was immediately threatened by the nuclear arms
57
race. Throughout the Cold War, peace was sustained globally but fought
locally, often by proxies for the superpowers. While the number of wars has
diminished over the last decade, peace is still sought, primarily in Africa and
the Middle East.
Freedom was sought early in the post-war world in the struggle to end imperialism; to halt totalitarian oppression and later to extend democratic
governance, human rights, and the rights of women, indigenous peoples, and
minorities. The success of many former colonies in attaining national
independence was followed by a focus on economic development to provide
basic necessities for the poorest two-thirds of the world and higher standards
of living for the wealthy third. Finally, it is only in the past 40 years that the
environment (local to global) became a key focus of national and international
law and institutions.
Although reinterpreted over time, peace, freedom, development, and the
environment remain prominent issues and aspirations. In the 1970s and
1980s, world commissions of notables were created to study such
international concerns, producing major documents that were often followed
by global conferences. Characteristic of these international commissions was
the effort to link together the aspirations of humankind—demonstrating how
the pursuit of one great value required the others. Sustainable development,
with its dual emphasis on the most recent concerns—development and
environment—is typical of such efforts.
The World Commission on Environment and Development was initiated by the
General Assembly of the United Nations in 1982, and its report, Our Common
Future, was published in 1987. It was chaired by then–Prime Minister of
Norway Gro Harlem Brundtland, thus earning the name the “Brundtland Commission.” The commission’s membership was split between developed and
developing countries. Its roots were in the 1972 Stockholm Conference on the
Human Environment—where the conflicts between environment and development were first acknowledged—and in the 1980 World Conservation Strategy of the International Union for the Conservation of Nature, which argued
for conservation as a means to assist development and specifically for the
sustainable development and utilization of species, ecosystems, and
resources. Drawing on these, the Brundtland Commission began its work
committed to the unity of environment and development.
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As Brundtland argued:
The environment does not exist as a sphere separate from human actions,
ambitions, and needs and attempts to defend it in isolation from human
concerns have given the very word “environment” a connotation of naivety in
some political circles. The word “development” has also been narrowed by
some into a very limited focus, along the lines of “what poor nations should do
to become richer,” and thus again is automatically dismissed by many in the
international arena as being a concern of specialists, of those involved in
questions of “development assistance.” But the “environment” is where we
live; and “development” is what we all do in attempting to improve our lot
within that abode. The two are inseparable.
As with previous efforts, major international meetings followed the report. The
United Nations Conference on Environment and Development (UNCED) in
Rio de Janeiro in 1992 (the so-called “Earth Summit”) issued a declaration of
principles, a detailed Agenda 21 of desired actions, international agreements
on climate change and biodiversity, and a statement of principles on forests.
Ten years later, in 2002, at the World Summit on Sustainable Development in
Johannesburg, South Africa, the commitment to sustainable development was
reaffirmed. In the interim, sustainable development as a concept, as a goal,
and as a movement spread rapidly and is now central to the mission of countless international organizations, national institutions, corporate enterprises,
“sustainable cities,” and locales.
5.8.2 DEFINITIONS
The Brundtland Commission’s brief definition of sustainable development is
the “ability to make development sustainable—to ensure that it meets the
needs of the present without compromising the ability of future generations to
meet their own needs” is surely the standard definition when judged by its
widespread use and frequency of citation. The use of this definition has led
many to see sustainable development as having a major focus on
intergenerational equity. Although the brief definition does not explicitly mention the environment or development, the subsequent paragraphs, while rarely
quoted, are clear. On development, the report states that human needs are
basic and essential; that economic growth—but also equity to share resources
with the poor—is required to sustain them; and that equity is encouraged by
effective citizen participation. On the environment, the text is also clear:
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The concept of sustainable development does imply limits—not absolute limits
but limitations imposed by the present state of technology and social
organization on environmental resources and by the ability of the biosphere to
absorb the effects of human activities.
In the years following the Brundtland Commission’s report, the creative ambiguity of the standard definition, while allowing a range of disparate groups to
assemble under the sustainable development tent, also created a veritable
industry of deciphering and advocating what sustainable development really
means. One important study—by the Board on Sustainable Development of
the U.S. National Academy of Sciences—sought to bring some order to the
broad literature its members reviewed. In its report, Our Common Journey: a
Transition toward Sustainability, the board focused on the seemingly inherent
distinction between what advocates and analysts sought to sustain and what
they sought to develop, the relationship between the two, and the time horizon
of the future.
Thus under the heading “what is to be sustained,” the board identified three
major categories—nature, life support systems, and community—as well as
intermediate categories for each, such as Earth, environment, and cultures.
Drawing from the surveyed literature, the board found that most commonly,
emphasis was placed on life support systems, which defined nature or environment as a source of services for the utilitarian life support of humankind.
The study of ecosystem services has strengthened this definition over time. In
contrast, some of the sustainable development literature valued nature for its
intrinsic value rather than its utility for human beings. There were also parallel
demands to sustain cultural diversity, including livelihoods, groups, and places
that constitute distinctive and threatened communities.
Similarly, there were three quite distinct ideas about what should be developed: people, economy, and society. Much of the early literature focused on
economic development, with productive sectors providing employment,
desired consumption, and wealth. More recently, attention has shifted to
human development, including an emphasis on values and goals, such as
increased life expectancy, education, equity, and opportunity. Finally, the
Board on Sustainable Development also identified calls to develop society
that emphasized the values of security and well-being of national states,
60
regions, and institutions as well as the social capital of relationships and
community ties.
There was ready agreement in the literature that sustainable development
implies linking what is to be sustained with what is to be developed, but here,
too, the emphasis has often differed from extremes of “sustain only” to
“develop mostly” to various forms of “and/or.” Similarly, the time period of
concern, ambiguously described in the standard definition as “now and in the
future,” has differed widely. It has been defined from as little as a
generation—when almost everything is sustainable—to forever—when surely
nothing is sustainable.
The 2002 World Summit on Sustainable Development marked a further
expansion of the standard definition with the widely used three pillars of
sustainable development: economic, social, and environmental. The Johannesburg Declaration created “a collective responsibility to advance and
strengthen the interdependent and mutually reinforcing pillars of sustainable
development—economic
development,
social
development
and
environmental protection—at local, national, regional and global levels.” In so
doing, the World Summit addressed a running concern over the limits of the
framework of environment and development, wherein development was
widely viewed solely as economic development. For many under the common
tent of sustainable development, such a narrow definition obscured their
concerns for human development, equity, and social justice.
Thus while the three pillars were rapidly adopted, there was no universal
agreement as to their details. A Web search of the phrase “three pillars of
sustainable development” finds a wide variety of environmental, economic,
and social pillars with differences most pronounced in characterizing the
social pillar. Three major variants of social development are found, each of
which seeks to compensate for elements missing in the narrow focus on
economic development. The first is simply a generic non-economic social
designation that uses terms such as “social,” “social development,” and
“social progress.” The second emphasizes human development as opposed
to economic development: “human development,” “human well-being,” or just
“people.” The third variant focuses on issues of justice and equity: “social
justice,’’ “equity,” and “poverty alleviation.”
61
5.8.3 GOALS
Another way to define sustainable development is in what it specifically seeks
to achieve. To illustrate, it is helpful to examine three sets of goals that use
different time-horizons: the short-term (2015) goals of the Millennium Declaration of the United Nations; the two-generation goals (2050) of the Sustainability Transition of the Board on Sustainable Development; and the long-term
(beyond 2050) goals of the Great Transition of the Global Scenario Group.
UN Millennium Declaration
To mark the millennium, heads of state gathered in New York at the United
Nations in September 2000. There, the UN General Assembly adopted some
60 goals regarding peace; development; environment; human rights; the
vulnerable, hungry, and poor; Africa; and the United Nations. Many of these
contained specific targets, such as cutting poverty in half or insuring universal
primary school education by 2015. For eight of the major goals, progress is
monitored by international agencies. In 2004, these agencies concluded that
at existing rates of progress, many countries will fall short of these goals,
particularly in Africa. Yet the goals still seemed attainable by collective action
by the world community and national governments. To do so, the Millenni-um
Project, commissioned by the UN secretary-general, recently estimated that
the additional financial resources that would be required to meet the
Millennium Development Goals are $135 billion in 2006, rising to $195 billion
in 2015. This roughly represents a doubling of official aid flows over current
levels and is still below the UN goal of aid flows from industrialized to
developing countries of 0.7 percent of the gross national product for industrialized countries.
Sustainability Transition of the Board on Sustainable Development
In 1995, the Board on Sustainable Development of the U.S. National
Academy of Sciences sought to make sustainable development more meaningful to scientific analysis and contributions. To do so, the board decided to
focus on a two-generation time horizon and to address the needs of a global
population with half as many more people as there are today—needs that, if
met successfully, are not likely to be repeated within the next century or two
because of the demographic transition. In that time period, the board
suggested that a minimal sustainability transition would be one in which the
62
world provides the energy, materials, and information to feed, nurture, house,
educate, and employ the many more people of 2050—while reducing hunger
and poverty and preserving the basic life support systems of the planet. To
identify more specific goals, of meeting human needs, reducing hunger and
poverty, and preserving the basic life support systems of the planet, the board
searched the text and statements from recent global conferences, world
summits, international environmental treaties, and assessments. In so doing,
the board in 1995 anticipated the 2000 Millennium Declaration goals, many of
which were incorporated into its analysis of goals and targets. Less sanguine
than the UN, the board determined it would take a generation to reach the
2015 goals of the Millennium Declaration and another generation to achieve
the board’s goals of meeting human needs for a 2050 population.
Great Transition of the Global Scenario Group
With the assistance of the Global Scenario Group, the Board on Sustainable
Development conducted a scenario analysis of a proposed “Sustainability
Transition,” focusing specifically on hunger and the emission of greenhouse
gasses. This initial analysis served as the subsequent basis of the Policy
Reform Scenario of the Global Scenario Group and concluded that a
sustainability transition is possible without positing either a social revolution or
a technological miracle. But it is “just” possible, and the technological and
social requirements to move from business as usual—without changing
lifestyles, values, or economic system—is daunting. Most daunting of all is the
governmental commitment required to achieve it and the political will to do so.
Finally, the Global Scenario Group also prepared a more idealistic Great
Transition Scenario that not only achieved the goals of the sustainability
transition outlined by the Board on Sustainable Development but went further
to achieve for all humankind “a rich quality of life, strong human ties and a
resonant connection to nature.” In such a world, it would be the quality of
human knowledge, creativity, and self-realization that represents
development, not the quantity of goods and services. A key to such a future is
the rejection of material consumption beyond what is needed for fulfillment or
for a “good life.” Beyond these goals, however, the details of this good life are
poorly described.
5.8.4 INDICATORS
63
Still another way to define sustainable development is in how it is measured.
Indeed, despite sustainable development’s creative ambiguity, the most serious efforts to define it, albeit implicit in many cases, come in the form of
indicators. Combining global, national, and local initiatives, there are literally
hundreds of efforts to define appropriate indicators and to measure them.
Recently, a dozen such efforts were reviewed. Half were global in coverage,
using country or regional data (the UN Commission on Sustainable Development, Consultative Group on Sustainable Development Indicators, Wellbeing Index, Environmental Sustainability Index, Global Scenario Group, and the
Ecological Footprint). Of the remaining efforts, three were country studies (in
the United States, the Genuine Progress Indicator and the Interagency
Working Group on Sustainable Development Indicators, and in Costa Rica,
the System of Indicators for Sustainable Development); one was a city study
(the Boston Indicators Project); one was global in scope but focused on
indicators of unsustainability (State Failure Task Force); and one focused on
corporate and nongovernmental entities (Global Reporting Initiative).
Table 5.2 lists each study with its source, the number of indicators used, and
the implicit or explicit definitions used to describe what is to be sustained,
what is to be developed, and for how long.
Two major observations emerge. The first is the extraordinarily broad list of
items to be sustained and to be developed. These reflect the inherent malleability of “sustainable development” as well as the internal politics of the
measurement efforts. In many of the cases, the initiative is undertaken by a
diverse set of stakeholders, and the resulting lists reflect their varied aspirations. For example, in the UN Commission on Sustainable Development,
the stakeholders are nations negotiating how to measure their relative
progress or lack of progress toward sustainable development. In the Boston
Indicators Project, the stakeholders are community members with varied
opinions about desirable goals, policies, and investment priorities for the
future. In the Global Reporting Initiative, the stakeholders are corporations,
investors, regulatory agencies, and civil society groups discussing how to
account for corporate actions affecting sustainable development. With many
stakeholders, each with different definitions, achieving consensus often takes
the form of long “laundry lists” of indicators, and definitional differences are
downplayed in favor of reaching a common set of indicators. Thus, to be
inclusive, the range of indicators becomes very broad. Half the examined
initiatives, however, represent less-inclusive research or advocacy groups
64
who share a more narrow and homogenous view of sustainable development.
While also assembling large numbers of indicators, these groups tend to
aggregate them to reflect their distinctive vision of sustainability.
A second observation is that few of the efforts are explicit about the time
period in which sustainable development should be considered. Despite the
emphasis in the standard definition on intergenerational equity, there seems
in most indicator efforts a focus on the present or the very short term. Three
exceptions, however, are worth noting: The UN Commission on Sustainable
Development uses some human development indicators defined in terms of a
single generation (15–25 years), the Global Scenario Group quantifies its
scenarios through 2050 (approximately two generations), and the Ecological
Footprint argues that in the long run an environmental footprint larger than
one Earth cannot be sustained. Overall, these diverse indicator efforts reflect
the ambiguous time horizon of the standard definition—“now and in the
future.”
Table 5.2 : Definitions of sustainable development implicitly or explicitly
adopted by selected indicator initiatives
Indicator
initiative
Number
of
indicator
s
Implicit or
explicit
definition
?
What is to be
sustained?
What is to be
developed?
For how
long?
Commission
on
Sustainable
Development
58
Implicit,
but
informed
by Agenda
21
Climate, clean air,
land productivity,
ocean productivity,
fresh water, and
biodiversity
Equity, health,
education,
housing, security,
stabilized
population
Sporadic
references
to 2015
Consultative
Group on
Sustainable
Development
Indicatorsb
46
Same as
above
Same as above
Same as above
Not stated;
uses data
for 1990
and 2000
Wellbeing
88
Explicit
“A condition in
which the
ecosystem
maintains its
diversity and
“A condition in
which all members
of society are able
to determine and
meet their needs
Not stated;
uses most
recent data
as of 2001
and
a
Indexc
65
Environment
al
Sustainability
Indexd
68
Explicit
quality—and thus
its capacity to
support people and
the rest of life—and
its potential to
adapt to change
and provide a wide
change of choices
and opportunities
for the future”
and have a large
range of choices
to meet their
potential”
includes
some
indicators
of recent
change
(such as
inflation
and
deforestati
on)
“Vital
environmental
systems are
maintained at
healthy levels, and
to the extent to
which levels are
improving rather
than deteriorating”
[and] “levels of
anthropogenic
stress are low
enough to
engender no
demonstrable harm
to its environmental
systems.”
Resilience to
environmental
disturbances
(“People and
social systems are
not vulnerable (in
the way of basic
needs such as
health and
nutrition) to
environmental
disturbances;
becoming less
vulnerable is a
sign that a society
is on a track to
greater
sustainability”);
“institutions and
underlying social
patterns of skills,
attitudes, and
networks that
foster effective
responses to
environmental
challenges”; and
cooperation
among countries
Not stated;
uses most
recent data
as of 2002
and
includes
some
indicators
of recent
change
(such as
deforestati
on) or
predicted
change
(such as
population
in 2025)
“to manage
common
environmental
66
problems”
Genuine
Progress
26
Explicit
Clean air, land, and
water
Economic
performance,
families, and
security
Not stated;
computed
annually
from
1950–2000
65
Explicit
“Preserving the
essential health,
services, and
beauties of the
earth requires
stabilizing the
climate at safe
levels, sustaining
energy, materials,
and water
resources, reducing
toxic emissions,
and maintaining the
world’s ecosystems
and habitats.”
Institutions to
“meet human
needs for food,
water, and health,
and provide
opportunities for
education,
employment and
participation”
Through
2050
6
Explicit
“The area of
biologically
productive land and
water required to
produce the
resources
consumed and to
assimilate the
wastes produced
by humanity”
Not explicitly stated; computed
annually from 1961–1999
Indicatore
Global
Scenario
Groupf
Ecological
Footprintg
67
U.S.
Interagency
Working
Group on
Sustainable
Developmen
t Indicatorsh
40
Explicit
Environment,
natural resources,
and ecosystem
services
Dignity, peace,
equity, economy,
employment,
safety, health, and
quality of life
Current
and future
generation
s
Costa Ricai
255
Implicit
Ecosystem
services, natural
resources, and
biodiversity
Economic and
social
development
Not stated;
includes
some time
series
dating
back to
1950
Boston
Indicator
159
Implicit
Open/green space,
clean air, clean
water, clean land,
valued ecosystems,
biodiversity, and
aesthetics
Civil society,
culture, economy,
education,
housing, health,
safety,
technology, and
transportation
Not stated;
uses most
recent data
as of 2000
and some
indicators
of recent
change
(such as
change in
poverty
rates)
75
Explicit
Intrastate
peace/security
Two years
97
Implicit
Reduced
consumption of raw
materials and
reduced emissions
of environmental
contaminants from
production or
product use
Profitability,
employment,
diversity of
workforce, dignity
of workforce,
health/safety of
workforce, and
health/safety/priva
cy of customers
Projectj
State Failure
Task Forcek
Global
Reporting
Initiativel
Current
reporting
year
5.8.5 VALUES
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Still another mode of defining sustainable development is through the values
that represent or support sustainable development. But values, like sustainable development, have many meanings. In general, values are expressions
of, or beliefs in, the worth of objects, qualities, or behaviors. They are typically
expressed in terms of goodness or desirability or, conversely, in terms of
badness or avoidance. They often invoke feelings, define or direct us to goals,
frame our attitudes, and provide standards against which the behaviors of
individuals and societies can be judged. As such, they often overlap with
sustainability goals and indicators. Indeed, the three pillars of sustainable
development; the benchmark goals of the Millennium Declaration, the
Sustainability Transition, and the Great Transition; and the many indicator
initiatives are all expressions of values.
But these values, as described in the previous sections, do not encompass
the full range of values supporting sustainable development. One explicit
statement of supporting values is found in the Millennium Declaration.
Underlying the 60 specific goals of the Millennium Declaration is an articulated
set of fundamental values seen as essential to international relations:
freedom, equality, solidarity, tolerance, respect for nature, and shared
responsibility (see the box on page 16).
The Millennium Declaration was adopted by the UN General Assembly, but
the origins of the declaration’s set of fundamental values are unclear. In
contrast, the origins of the Earth Charter Initiative—which defines the Earth
Charter as a “declaration of fundamental principles for building a just,
sustainable, and peaceful global society in the 21st century”- is well documented.
Check your progress 2.
Notes :
a)
Write your answer in the space given below.
b)
Compare your answer with key, given at the end of the unit.
Que.
3. What is sustainable development? Discuss its indicators, goals, and values.
4. What is environmental management?
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The initiative answers the call of the World Commission on Environment and
Development for creation of “a universal declaration” that would “consolidate
and extend relevant legal principles,” create “new norms . . . needed to
maintain livelihoods and life on our shared planet,” and “ guide state behavior
in the transition to sustainable development.” An effort to draft a charter at the
1992 Earth Summit was unsuccessful. In 1994 a new Earth Charter Initiative
was launched that involved “the most open and participatory consultation
process ever conducted in connection with an international document.
Thousands of individuals and hundreds of organizations from all regions of
the world, different cultures, and diverse sectors of society . . . participated.”
Released in the year 2000, the Earth Charter has been endorsed by more
than 14,000 individuals and organizations worldwide representing millions of
members, yet it has failed to attain its desired endorsement or adoption by the
2002 World Summit on Sustainable Development or the UN General
Assembly.
The values of the Earth Charter are derived from “contemporary science,
international law, the teachings of indigenous peoples, the wisdom of the
world’s great religions and philosophical traditions, the declarations and
reports of the seven UN summit conferences held during the 1990s, the global
ethics movement, numerous nongovernmental declarations and people’s
treaties issued over the past thirty years, and best practices for building
sustainable communities.” For example, in 1996, more than 50 international
law instruments were surveyed and summarized in Principles of
Environmental Conservation and Sustainable Development: Summary and
Survey. Four first-order principles were identified and expressed in the Earth
Charter as the community of life, ecological integrity, social and economic
justice, and democracy, nonviolence, and peace. Sixteen second-order
principles expand on these four, and 61 third-order principles elaborate on the
16. For example, the core principal of social and economic justice is
elaborated by principles of equitable economy, eradication of poverty, and the
70
securing of gender equality and the rights of indigenous peoples. In turn, each
of these principles is further explicated with three or four specific actions or
intentions.
5.8.6 PRACTICE
Finally—and in many ways, most importantly—sustainable development is
defined in practice. The practice includes the many efforts at defining the
concept, establishing goals, creating indicators, and asserting values. But
additionally, it includes developing social movements, organizing institutions,
crafting sustainability science and technology, and negotiating the grand
compromise among those who are principally concerned with nature and
environment, those who value economic development, and those who are
dedicated to improving the human condition.
A Social Movement
Sustainable development can be viewed as a social movement—“a group of
people with a common ideology who try together to achieve certain general
goals.” In an effort to encourage the creation of a broadly based social movement in support of sustainable development, UNCED was the first international, intergovernmental conference to provide full access to a wide range of
nongovernmental organizations (NGOs) and to encourage an independent
Earth Summit at a nearby venue. More than 1,400 NGOs and 8,000
journalists participated. One social movement launched from UNCED was the
effort described above to create an Earth Charter, to ratify it, and to act upon
its principles.
In 2002, 737 new NGOs and more than 8,046 representatives of major groups
(business, farmers, indigenous peoples, local authorities, NGOs, the scientific
and technological communities, trade unions, and women) attended the World
Summit on Sustainable Development in Johannesburg. These groups
organized themselves into approximately 40 geographical and issue-based
caucuses.
But underlying this participation in the formal international sustainable
development events are a host of social movements struggling to identify
what sustainable development means in the context of specific places and
peoples. One such movement is the effort of many communities, states,
71
provinces, or regions to engage in community exercises to define a desirable
sustainable future and the actions needed to attain it. Examples include
Sustainable Seattle, Durban’s Local Agenda 21 Programme, the Lancashire
County Council Local Agenda 21 Strategy, and the Minnesota Sustainable
Development Initiative.
Three related efforts are the sustainable livelihoods movement, the global
solidarity movement, and the corporate responsibility movement. The movement for sustainable livelihoods consists of local initiatives that seek to create
opportunities for work and sustenance that offer sustainable and credible
alternatives to current processes of development and modernization.
Consisting primarily of initiatives in developing countries, the movement has
counterparts in the developed world, as seen, for example, in local efforts in
the United States to mandate payment of a “living wage” rather than a
minimum wage.
The global solidarity movement seeks to support poor people in developing
countries in ways that go beyond the altruistic support for development funding. Their campaigns are expressed as antiglobalization or “globalization from
below” in critical appraisals of major international institutions, in the movement
for the cancellation of debt, and in critiques of developed-world policies—such
as agricultural subsidies—that significantly impact developing countries and
especially poor people.
The corporate responsibility movement has three dimensions: various campaigns by NGOs to change corporate environmental and social behavior;
efforts by corporations to contribute to sustainable development goals and to
reduce their negative environmental and social impacts; and international
initiatives such as the UN Global Compact or the World Business Council for
Sustainable Development that seek to harness the knowledge, energies, and
activities of corporations to better serve nature and society. For instance, in
the just-selected Global 100, the most sustainable corporations in the world,
the top three corporations were Toyota, selected for its leadership in
introducing hybrid vehicles; Alcoa, for management of materials and energy
efficiency; and British Petroleum, for leadership in greenhouse gas emissions
reduction, energy efficiency, renewables, and waste treatment and handling.
A related social movement focuses on excessive material consumption and its
impacts on the environment and society and seeks to foster voluntary
72
simplicity of one form or another. These advocates argue that beyond certain
thresholds, ever-increasing consumption does not increase subjective levels
of happiness, satisfaction, or health. Rather, it often has precisely the opposite effect. Thus, these efforts present a vision of “the good life” in which
people work and consume less than is prevalent in today’s consumer-driven
affluent societies.
As with any social movement, sustainable development encounters opposition. The opponents of sustainable development attack from two very different perspectives: At one end of the spectrum are those that view
sustainable development as a top-down attempt by the United Nations to
dictate how the people of the world should live their lives—and thus as a
threat to individual freedoms and property rights. At the other end are those
who view sustainable development as capitulation that implies development
as usual, driven by the interests of big business and multilateral institutions
and that pays only lip service to social justice and the protection of nature.
Institutions
The goals of sustainable development have been firmly embedded in a large
number of national, international, and nongovernmental institutions. At the
intergovernmental level, sustainable development is now found as a central
theme throughout the United Nations and its specialized agencies. Evidence
of this shift can be seen in the creation of the Division of Sustainable
Development within the United Nations Department of Economic and Social
Affairs, the establishment of a vice president for environmentally and socially
sustainable development at the World Bank, and the declaration of the United
Nations Decade of Education for Sustainable Development. Similarly,
numerous national and local governmental entities have been established to
create and monitor sustainable development strategies. According to a recent
survey by the International Council for Local Environment Initiatives, “6,416
local authorities in 113 countries have either made a formal commitment to
Local Agenda 21 or are actively undertaking the process,” and the number of
such processes has been growing dramatically. In addition to these governmental efforts, sustainable development has emerged in the organization
charts of businesses (such as Lafarge), consultancies (including CH2M Hill),
and investment indices (such as the Dow Jones Sustainability Index).
Sustainability Science and Technology
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Sustainable development is also becoming a scientific and technological
endeavor that, according to the Initiative on Science and Technology for
Sustainable Development, “seeks to enhance the contribution of knowledge to
environmentally sustainable human development around the world.” This
emerging enterprise is focused on deepening our understanding of socio-ecological systems in particular places while exploring innovative mechanisms
for producing knowledge so that it is relevant, credible, and legitimate to local
decision makers.
The efforts of the science and technology community to contribute to
sustainable development is exemplified in the actions of the major Academies
of Science and International Disciplinary Unions, in collaborative networks of
individual scientists and technologists, in emerging programs of
interdisciplinary education, and in many efforts to supply scientific support to
communities.
A Grand Compromise
One of the successes of sustainable development has been its ability to serve
as a grand compromise between those who are principally concerned with
nature and environment, those who value economic development, and those
who are dedicated to improving the human condition. At the core of this
compromise is the inseparability of environment and development described
by the World Commission on Environment and Development.
Thus, much of what is described as sustainable development in practice are
negotiations in which workable compromises are found that address the
environmental, economic, and human development objectives of competing
interest groups. Indeed, this is why so many definitions of sustainable
development include statements about open and democratic decisionmaking.
At the global scale, this compromise has engaged the wealthy and poor countries of the world in a common endeavor. Before this compromise was
formally adopted by UNCED, the poorer countries of the world often viewed
demands for greater environmental protection as a threat to their ability to
develop, while the rich countries viewed some of the development in poor
countries as a threat to valued environmental resources. The concept of
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sustainable development attempts to couple development aspirations with the
need to preserve the basic life support systems of the planet.
5.8.7 SO, WHAT IS SUSTAINABLE DEVELOPMENT?
Since the Brundtland Commission first defined sustainable development,
dozens, if not hundreds, of scholars and practitioners have articulated and
promoted their own alternative definition; yet a clear, fixed, and immutable
meaning remains elusive. This has led some observers to call sustainable
development an oxymoron: fundamentally contradictory and irreconcilable.
Further, if anyone can redefine and reapply the term to fit their purposes, it
becomes meaningless in practice, or worse, can be used to disguise or
greenwash socially or environmentally destructive activities.
Yet, despite these critiques, each definitional attempt is an important part of
an ongoing dialogue. In fact, sustainable development draws much of its
resonance, power, and creativity from its very ambiguity. The concrete
challenges of sustainable development are at least as heterogeneous and
complex as the diversity of human societies and natural ecosystems around
the world. As a concept, its malleability allows it to remain an open, dynamic,
and evolving idea that can be adapted to fit these very different situations and
contexts across space and time. Likewise, its openness to interpretation
enables participants at multiple levels, from local to global, within and across
activity sectors, and in institutions of governance, business, and civil society
to redefine and reinterpret its meaning to fit their own situation.
Thus, the concept of sustainability has been adapted to address very different
challenges, ranging from the planning of sustainable cities to sustainable
livelihoods, sustainable agriculture to sustainable fishing, and the efforts to
develop common corporate standards in the UN Global Compact and in the
World Business Council for Sustainable Development.
Despite this creative ambiguity and openness to interpretation, sustainable
development has evolved a core set of guiding principles and values, based
on the Brundtland Commission’s standard definition to meet the needs, now
and in the future, for human, economic, and social development within the
restraints of the life support systems of the planet. Further, the connotations of
both of the phrase’s root words, “sustainable” and “development” are
generally quite positive for most people, and their combination imbues this
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concept with inherent and near-universal agreement that sustainability is a
worthwhile value and goal—a powerful feature in diverse and conflicted social
contexts.
Importantly, however, these underlying principles are not fixed and immutable
but the evolving product of a global dialogue, now several decades old, about
what sustainability should mean. The original emphasis on economic development and environmental protection has been broadened and deepened to
include alternative notions of development (human and social) and alternative
views of nature (anthropocentric versus ecocentric). Thus, the concept
maintains a creative tension between a few core principles and openness to
reinterpretation and adaptation to different social and ecological contexts.
Sustainable development thus requires the participation of diverse
stakeholders and perspectives, with the ideal of reconciling different and
sometimes opposing values and goals toward a new synthesis and
subsequent coordination of mutual action to achieve multiple values
simultaneously and even synergistically.
As real-world experience has shown, however, achieving agreement on sustainability values, goals, and actions is often difficult and painful work, as
different stakeholder values are forced to the surface, compared and
contrasted, criticized and debated. Sometimes individual stakeholders find the
process too difficult or too threatening to their own values and either reject the
process entirely to pursue their own narrow goals or critique it ideologically,
without engaging in the hard work of negotiation and compromise.
Critique is nonetheless a vital part of the conscious evolution of sustainable
development—a concept that, in the end, represents diverse local to global
efforts to imagine and enact a positive vision of a world in which basic human
needs are met without destroying or irrevocably degrading the natural systems on which we all depend.
5.9
LETS SUM UP
Every ecosystem is subject to perturbations such as climate, nutrient
fluctuation, loss of biodiversity, and introduction of exotic species, that can
alter ecosystem structure and function.
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Whittaker (1972) distinguished three types of diversity viz alpha, beta and
gamma diversity.
Robert MacArthur [2002] proposed measuring the stability of an ecosystem. In
1975, Daniel Goodman summarized the mounting evidence against the
diversity stability hypothesis by responding to each of Elton’s arguments for it.
Invasive species are non-indigenous plants or animals species that adversely
affect the habitats they invade economically, environmentally or ecologically.
Biological species invasions alter ecosystems in a multitude of ways.
Worldwide, an estimated 80% of endangered species could suffer losses by
competition with, or predation by, invasive species.
Environmental Impact Assessment (EIA) is an important management tool for
ensuring optimal use of natural resources for sustainable development. EIA is
a relatively new planning and decision-making tool.
EIA
extrapolates from
scientific knowledge
to
assess the problem
consequences of some human interventions on nature.
Grumbine (1994) suggests the ecological management which is based on
three observations a. to protect biological diversity the processes that
produced it must be protected as well; b. species richness alone is not a good
measure of management success; and c. management must be planned for
the long-term, possibly even for the indefinite future, i.e., ecological
management is intended to result in both a sustainable system and a set of
sustainable management activities.
Goldstein (1999) argues that the ecological management not only often fails
to honor those principles, but also that it is largely an attempt to bypass the
requirement for life history information on all species of concern.
The concept of sustainable development is “Humanity has the ability to make
development sustainable—to ensure that it meets the needs of the present
without compromising the ability of future generations to meet their own
needs.”
The three pillars of sustainable development; the benchmark goals of the
Millennium Declaration, the Sustainability Transition, and the Great Transition;
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and the many indicator initiatives are all values of the sustainable
development.
Sustainable development thus requires the participation of diverse
stakeholders and perspectives, with the ideal of reconciling different and
sometimes opposing values and goals toward a new synthesis and
subsequent coordination of mutual action to achieve multiple values
simultaneously and even synergistically.
5.10 CHECK YOUR PROGRESS : THE KEY
1) Environmental Impact Assessment (EIA) is an important management tool
for ensuring optimal use of natural resources for sustainable development.
EIA is a relatively new planning and decision-making tool. Describe its
importance in Indian context.
2) There are two main impacts of invasion :
a. Ecological impacts
b. Genetic pollution
Give economic benefits in forestry, costs, agriculture, and tourism sector.
3) These are parameter of sustainability measurement. The measurements
used as the quantitative basis for the informed management of
sustainability. The metrics used for the measurement of sustainability
include indicators, benchmarks, audits, indexes, accounting and reporting
systems and more, and they can apply on all scales from global to local.
4) To protect biological diversity the processes that produced it must be
protected as well. Species richness alone is not a good measure of
management success.
5) Management must be planned for the long-term, possibly even for the
indefinite future, i.e., ecological management is intended to result in both a
sustainable system and a set of sustainable management activities.
5.11 ASSIGNMENTS/ ACTIVITIES
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It is compulsory for every student to complete an assignment/ activity/ project
work from any known prospects of present study. Explain the following (any
one):
a. Ecological diversity and stability
b. Invasive plant species and impact on ecosystem
c. Environmental management
d. Environmental priorities in India.
e. Environmental monitoring
f. Bioindicators
g. Sustainable development : goals, indicators, values, and practices
5.12 REFERENCES/ FURTHER READINGS
B. Walker. 1999. The ecosystem approach to conservation: Reply to Goldstein.
Conservation Biology, 13:436–437.
Cadotte, M. W., McMahon, S. M. & Fukami, T. (eds) 2005 Conceptual ecology and
invasions biology: reciprocal approaches to nature. Dordrecht, The Netherlands:
Springer.
Lehman, Clarence and Tilman, David. 2000. “Biodiversity, Stability, and Productivity
in Competitive Communities.” American Naturalist 156: 534-552.
M. A. Harwell, V. Myers, T. Young, A. Bartuska, N. Gassman, J. H. Gentile, C. C.
Harwell, S. Appelbaum, J. Barko, B. Causey, C. Johnson, A. McLean, R. Smola,
P. Templet, and S. Tosini. 1999. A framework for an ecosystem integrity report
card. Bio Science, 49:543–556.
M. G. Marshall and T. R. Gurr, Peace and Conflict 2003. College Park, MD: Center
for International Development and Conflict Management, University of Maryland.
M. Groom, G. K. Meffe, and C. R. Carroll. 2005. Principles of Conservation Biology.
Sinauer Associates, Sunderland, MA, 3rd edition.
May, Robert. 1974. Stability and Complexity in Model Ecosystems. 2nd Edition.
Princeton: Princeton University Press.
National Research Council, Policy Division, Board on Sustainable Development.
1999. Our Common Journey: A Transition toward Sustainability. National
Academy Press, Washington, DC.
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P. G. Risser. 1999. Examining relationships between ecosystem function and
biodiversity: Reply to Goldstein. Conservation Biology, 13:438–439.
P. Z. Goldstein. 1999. Functional ecosystems and biodiversity buzzwords.
Conservation Biology , 13:247–255.
R. E. Grumbine. 1994. What is ecosystem management? Conservation Biology,
11:41–47.
Shrader-Frechette, Kristin and McCoy, Earl. 1993. Method in Ecology. Cambridge,
UK: Cambridge University Press.
Tilman, D. 1989 Ecological experimentation: strengths and conceptual problems. In
Long-term studies in ecology: approaches and alternatives (ed. G. E. Likens),
pp. 136–157. New York: Springer-Verlag.
Whittaker, R. H. 1975 Communities and ecosystems, 2nd edn New York: MacMillan.
World Commission on Environment and Development (WCED), 1987. Our Common
Future, Oxford University Press, New York.
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