Environmental Management: Principles and practice

How stable are ecosystems?
Ecosystems are subject to natural and anthropogenic changes, some catastrophic
and sudden, but often gradual and less marked. Ecologists, botanists and
geomorphologists have argued that ecosystems tend towards a steady state achieved
through adaption to changes (Hill, 1987; Stone et al., 1996). Some economists and
political studies specialists have suggested economics, politics and social development
follow a predictable evolutionary path to a steady-state. ‘Stability’ can have a number
of meanings, including: lack of change in structure of an ecosystem; resistance to
perturbations; or speedy return to steady-state after disturbance (Troumbis, 1992:
252). Mitchell (1997:51) felt that basic concepts of ecosystem diversity and stability
did not adequately describe complex reality: ecosystems were inherently complex,
there were unlikely to be simple answers, and environmental managers must accept
that they could not just manage ecosystems, but that they were managing human
interactions with them.

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The ecosystem concept and ecosystem management
The ecosystem concept became a widely used conceptual tool for research after
1945; for example, it has been adopted in the studies of the International Biological
Program (Myers and Shelton, 1980). Nowadays, ecologists often adopt an ecosystems
approach when seeking to understand and monitor a given situation. The approach
focuses on energy flows or nutrient transformations. Biotic activity within an
ecosystem can be divided into that of producers, consumers and decomposers, and
efforts to study these may focus on population dynamics and productivity, predator-
prey relations, parasitism, and so on. Study of non-biotic aspects of an ecosystem
may focus on estimation of biomass or micrometeorology. In the last three decades
there has been a shift from description of the structure of ecosystems to a focus on
trying to understand function, processes, mechanisms and systems behaviour. There
is a much better understanding of the structure and function of ecosystems than was
the case in the 1960s, but there are still gaps in knowledge, leading to strong criticisms
of lack of scientific rigour and vagueness (Armitage, 1995:470).
The ecosystem concept allows the environmental manager to look at portions
of complex nature as an integrated system (Van Dyne, 1969:78; Holling, 1987).
The concept may be applied to cities or agriculture (urban ecosystems and
agroecosystems respectively), although these are not actually true, discrete units
in terms of energy flows or function. An ecosystems approach allows a holistic
view of how components work together, i.e. it can incorporate human dimensions
into biosphere functioning. This requires interdisciplinary teamwork that includes
consideration of science and social science issues (Darling and Dasmann, 1969;
Roe, 1996; Yaffee, 1996). Environmental managers may treat an ecosystem rather
like a factory: they seek to improve and sustain output and reduce costs but, unlike
a factory, there are often several different ‘products’ (agricultural produce, tourism,
water supply, conservation, etc).
A precise, universal definition of ecosystem management is impossible, partly
because it depends on the stance and outlook of the definer, partly because it is still
evolving, and also because it involves a diversity of actors—scientists, policy makers,
commerce, citizens, etc. It is not a science, nor it is a simple extension of traditional
resource management; rather it seeks a synthesis of ecosystem science and ecosystem
approaches, to provide a framework that links biophysical and socioeconomic research
and practice in a region or ecosystem through a holistic ecological and participatory
methodology (although how it might achieve these goals is usually less than clearly
stated) (Grumbine, 1994; 1997). Many of the principles used by ecosystem
management are normative, i.e. moral and ethical rather than strictly scientific, which
has attracted criticism (Likens, 1992; Haeuber, 1996). Concern has been voiced at
the lack of satisfactory established principles for ecosystem management (Brunner
and Clark, 1997). It is not always clear how ecosystems management differs from
environmental management, although the former involves application of the
ecosystem concept and use of an ecosystem boundary.
Increasingly, the emphasis is on sustainable ecosystem management, the goal
of which is to maintain ecosystem integrity and, if possible, produce food and other

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commodities on a sustained basis. The ecosystem approach helps define the temporal
and spatial scale of management. This requires a multidisciplinary or, better, an
interdisciplinary approach in order to deal with complexities of ecosystem function
and usage. Mitchell (1997:62) voiced concern that ecosystem management may lead
to a broad and possibly superficial approach in the effort to break down an over-
sectoral treatment; therefore he suggested that ecosystem management should be
integrated with organizational structures that continue along sectoral lines. Other
problems of ecosystems management include: the need to address complex problems
(di Castri and Hadley, 1985); that experience gained in one ecosystem may be of
limited value for other, even similar, ecosystems; the character of natural ecosystems
may be difficult to establish where there has been disturbance, so it is difficult to
agree what conservation or land restoration should aim for.
O’Neil (Cairns and Crawford, 1991:39) suggested the ecosystem approach
could be seen as methodology (with models to simulate the ecosystem) and mindset
(with a focus on function and properties of ecosystems) the strength of the approach
being synthesis of the complexity of problems faced, enabling assessment of
consequences. In practice there has been a good deal of fragmentation, for example:
ecosystem studies of risk; ecosystem quality management; assessment of ecosystem
potential; ecosystem conservation, and so on.
It is not only ecologists and environmental managers who have adopted an
ecosystems approach: many other disciplines frequently do so, including human
ecology (perhaps the first to do so—see chapter 13), cultural anthropology (Moran,
1990), political science, planning, management and urban studies. These users
generally seek to define a workable ‘ecosystem’ for study, and then apply ecological
concepts. Slocombe (1993:294) pointed out that the ‘ecosystems’ that are selected
as management and planning units are often larger than true ecosystems, and may
have considerable human activity affecting them.
It has been argued that an ecosystems approach should consider humans as