A large, contiguous geographic area in which the biological and physical components have similar structure and function. For example: the Klamath Ecoregion (or Bioregion).
The natural complex of plant and animal populations and the physical conditions that link them with a place. EXAMPLE: A river ecosystem would include the entire food chain linked to that riverŅalgae, insects, fish, fish-eating mammals, birds, and vegetationŅalong with the water, soil and air.
A species whose well-being (or lack thereof) can be projected over groups of animals who have similar life requisites. EXAMPLE: The decline of the northern spotted owl (considered an indicator for species that depend on old-growth forests) is a sign that the entire old-growth ecosystem is in trouble.
The decrease in total living space and the division of the remaining area into ever more isolated pieces. EXAMPLE: In many areas wildlife populations are trapped within "biological ghettos" and cut off from their migratory routes by roads, fences, fields, dams, urban sprawl, clear-cuts, aqueducts, etc.
An area drained by a river system, or a body of water into which many streams drain. EXAMPLES: Eel River watershed, Lake Tahoe basin.
Copyright Mendocino Environmental Center 1999
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