Sustainability has been a key concern in land-management and planning
circles for a long time. With ecosystem management, however, focus has
shifted from just maintaining "productivity of soil" to "sustaining the
integrity of the systems that support life and provide for a quality
existence." Zane Cornett and I worked up a definition for sustainability
A Definition of Sustainability for Ecosystem Management
Sustainability is at the heart of many current, and sometimes contentious,
discussions relating to all aspects of natural resource management. Part
of the struggle has been the search for a definition suitable for an
ecosystem management context. A definition is important whether developing
a framework or processes for ecosystem management. In defining
sustainability, our underlying premise is that ecosystem health is tightly
linked to the sustenance of humans, and the quality of their lives.
by David C. Iverson and Zane J Cornett
Our definition of sustainability builds upon a foundation of ecosystem
health and integrity, similar to that proposed by Bryan Norton (1992)
recently supported by James Kay (1993)2.
Maintaining the health and
integrity of ecosystems is necessary, because science is showing us that
the consequences of doing otherwise could disrupt ecosystem functions to
the point where human existence would no longer be one that we would
desire, nor one we would wish to leave to future generations.
We advocate the following definition for the purposes of ecosystem
Sustainability is a relationship between dynamic cultural, economic, and
biophysical systems associated across the landscape such that quality of
life for humans continues -- both for individuals and cultures. It is a
relationship in which the effects of human activities do not threaten the
integrity of the self-organizing systems that provide the context for
To further clarify this definition of sustainability, we need a
complementary definition for integrity. The philosophy of ecosystem
management integrates biophysical, cultural, and economic systems into the
single concept of "ecosystems".
An ecosystem has integrity if it retains its complexity and capacity for
self-organization (arguably its health) and sufficient diversity, within
its structures and functions, to maintain the ecosystem's self-organizing
complexity through time.
The definition for integrity is applicable to each of the economic,
cultural, and biophysical subsystems, as well as to the integrated
ecosystem. When trying to implement this definition, the issue of scale or
context is unavoidable. The integrity of biophysical systems, in
particular, are dependent upon their context, both spatially (across
landscapes) and temporally (multi-generational). Thus, a landscape would
have integrity if its ecosystems retain their complexity and capacity for
self-organization, and sufficient diversity, within their structures and
functions, to maintain the systems' self-organizing complexity through
These concepts are fundamentally linked to and driven by the reality of
five axioms of ecosystem management proposed by Norton:
- The Axiom of Dynamism: Nature is more profoundly a set of processes
than a collection of objects; all is in flux.
- The Axiom of Relatedness: All processes are related to all other
- The Axiom of Hierarchy: Processes are not related equally but unfold
in systems within systems, which differ mainly regarding the temporal
and spatial scale on which they are organized.
- The Axiom of Creativity: The processes of nature are self-organizing,
and all other forms of creativity depend on them. The vehicle of that
creativity is energy flowing through the systems that generates
complexity of organization through repetition and duplication.
- The Axiom of Differential Fragility: Ecological systems, which form
the context of all human activities, vary in the extent to which they
can absorb and equilibrate human-caused disruptions in their creative
1 Norton, Bryan G. 1992. "A New Paradigm for Environmental Management," in
Ecosystem Health: New Goals for Environmental Management, Robert Constanza,
Bryan G. Norton, and Benjamin D. Haskell, eds., Island Press.
2 Kay, James J. 1993. "On the Nature of Ecological Integrity: Some Closing
Comments," in Ecological Integrity and the Management of Ecosystems,
Stephen Woodley, James Kay, and George Francis, eds., St. Lucie Press.