These levels were linked with the emergence of previously inconspicuous Daphnia species (Edmondson and Litt, 1982) and provide evidence of how changes in a lake's food web can have a strong influence on its water clarity. Edmondson (1991) reviews the details of the Lake Washington story and illustrates the sometimes complex interplay between basic science and lake management issues.

This program illustrates how a single leader with long-term support for research can do a very effective job of fostering fundamental ecosystem understanding. It also illustrates the precarious nature of such programs; since Edmondson's retirement in the mid-1980s, the University of Washington has chosen not to continue its important history of limnological research and has hired no replacement for him.

Coweeta Experimental Forest

Like the program at HBEF, research at Coweeta Experimental Forest illustrates how a research center can generate important general information about both aquatic and terrestrial ecosystem processes (Swank and Crossley, 1988). In addition to providing fundamental information on the control of forest type over the amount of water exiting a watershed, work at Coweeta has documented how forest conditions influence the amount of organic materials transported by streams (Wallace et al., 1982; Tate and Meyer, 1983). Other research has shown how watershed conditions affect the basic chemistry and biology of streams (Webster and Patten, 1979; Meyer and Tate, 1983) and how the organisms occurring within streams influence the processing of organic matter (Meyer et al., 1988; Perlmutter and Meyer, 1991). The removal of all aquatic insects produced substantial changes in the transport of materials by streams, demonstrating the importance of insects in fundamental stream processes and further illustrating the usefulness of a large-scale experimental approach (Cuffney et al., 1984).

H. J. Andrews Experimental Forest

One of the major synthetic perspectives in river ecology, the River Continuum Concept, concerns how the proportions of fundamental ecosystem processes change systematically with distance downstream from headwaters to the ocean. This model can be traced in part to interactions arising at the H. J. Andrews Experimental Forest (HJAEF) along with the Stroud Water Research Center (Vannote et al., 1980). Multidisciplinary perspectives at HJAEF have helped develop an understanding of how geomorphology exerts a fundamental influence on basic ecosystem processes (Swanson et al., 1988). Additionally, work at HJAEF has indicated how coarse woody debris can influence stream processes, such as the rates at which water is transported, the decomposition of organic materials, and

The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement