Assessment of the Effects of Land Use Changes on Lower St. Johns River Basin Watershed Detrital Input. Final Report

摘要

The research described in this report provides a basis for a predictive understanding of how historical changes in land use have affected the role of terrestrial leaf litter in aquatic food webs of the Lower St. Johns River Basin (LSJRB). Like much of the eastern United State, development of this watershed has resulted in large quantitative and qualitative changes to riparian plant communities. These changes, in concert with increases in nutrient loading, are likely to have had a great effect on the structure and function of aquatic food webs due to the close relationship between terrestrial leaf detritus and invertebrate communities of forested headwater streams. The study streams selected represented a gradient of urban-rural land-use from the lowest to highest intensity of urban land-cover. Twenty catchments with streams will similar discharge, catchment area, geomorphology were selected with help from SJWMD personnel. Four catchments with similar channel forms and representing the breadth of the urban-rural gradient were designated as locations for intensive study ('focus' catchments).