Streamside Forests and the Physical, Chemical, and Trophic Characteristics of Piedmont Streams in Eastern North America

It is now clear that water and habitat quality in the coastal embayments of eastern North America are greatly affected by the quality of water and habitat in the thousands of feeder streams and rivers comprising their watershed. In this paper I suggest that the quality of streamside forests may be the single most important factor altered by humans that affects the structure and function, and ultimately water quality, of the streams providing water to the coastal embayments. I use comparative data from forested and deforested reaches of streams in a small Piedmont watershed (White Clay Creek) to illustrate the actual and/or potential effects of streamside forests on: (i) availability of habitat; (ii) the nutrient chemistry of the water; and (iii) the quantitative and qualitative nature of the primary food base (organic detritus and algae) supporting higher trophic levels in streams. Also discussed are the potential role of streamside forests in partially mitigating the flux of sediment and nutrients into aquatic ecosystems, the effects of global warming on stream temperatures, and the deleterious effects on stream organisms of the increased levels of UV radiation associated with global ozone depletion. Current methods and approaches for streamside forest restoration are presented.