Temporal and Spatial Scales
نویسنده
چکیده
H uman activities have degraded substantial portions of the nation’s ecological resources, including physical and biological aquatic systems. The effects are continuing and cumulative, and few high-quality aquatic ecosystems remain in the United States. Concern about these diminishing resources has resulted in numerous restoration programs. Some are well conceived and address complex ecosystem interactions. However, most restoration begins with a broad ecosystem issue and quickly narrows because of jurisdictional politics, land ownership, user interest, funding, or time. Too often, this narrowed view leads to restoration that is well designed and well intentioned but irrelevant and ineffective. In some cases, expensive projects are conducted where they will have little effect. In other cases, a restoration project is completed only to be destroyed by the next moderate storm. In still other cases, restoration designed to benefit one component of the ecosystem severely damages other components. A common thread through such failed restoration is that the plans consider only a particular site or problem and ignore the greater context of geography, time, and ecology. For example, restoration to address a dwindling run of anadromous salmonids (salmon or trout that live in salt water but migrate to spawn in freshwater) must not only discern the complex reasons why the run is dwindling, but how local projects might contribute to the solution. In some cases, a proposed local project may be ineffective because it covers too small an
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تاریخ انتشار 1999