[Contents]

Definitions

As the Service implements an ecosystem approach to fish and wildlife conservation, we need a common language. The following definitions have been adopted; others will be added as needed. The definitions reflect a synthesis of the many definitions that can be found in ecology literature. Some are followed by additional definitions taken from the literature.

Adaptive Management: Management that acknowledges uncertainty and the value of experimentation and learning from experience.

Biodiversity: The variety of life and its processes, including the variety of living organisms, the genetic differences among them, and the communities and ecosystems in which they occur.

The variety of organisms considered at all levels, from genetic variants belonging to the same species through arrays of species to arrays of genera, families, and still higher taxonomic levels; includes the variety of ecosystems, which comprise both the communities of organisms within particular habitats and the physical conditions under which they live [Wilson, 1993].

Cross-program: Communication and cooperation between multiple programs.

The Service is organized into programs such as Refuges, Migratory Birds, Law Enforcement, Fisheries, International Affairs, Endangered Species, and Environmental Contaminants.

Ecosystem: Dynamic and interrelating complex of plant and animal communities and their associated non-living environment.

The interacting populations of plants, animals, and microorganisms occupying an area, plus their physical environment. The living organisms in an ecosystem are collectively called a community, sometimes natural community or biotic community [Hunter, 1990].

A biological community is defined by the species that occupy a particular locality and the interactions between those species. A biological community together with its associated physical environment is termed an ecosystem [Primack, 1993].

Ecosystem Approach: Protecting or restoring the natural function, structure, and species composition of an ecosystem, recognizing that all components are interrelated.

Management of natural resources using systemwide concepts to ensure that all plants and animals in ecosystems are maintained at viable levels in native habitats and that basic ecosystem processes are perpetuated indefinitely [Clark and Zaunbrecher, 1987].

Ecosystem Unit: An area delineated on the Service's watershed-based map.

Focus Area: Within an ecosystem unit, an area where more local and concentrated effort is appropriate.

Natural: Substantially unaffected by human activities.

Sustainability: The ability to maintain ecological processes and functions, biological diversity, and productivity over time.

Watershed: The area drained by a river or stream and its tributaries.

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