As John Muir, the eminent American naturalist and founder of the Sierra Club wrote, “When we try to pick out anything by itself, we find it hitched to everything else in the universe.” Attempting to understand and predict the response of an ecosystem to large-scale stresses such as acid deposition, nonpoint source pollution, or climate change exemplifies this truth. This effort requires the integration of knowledge from a range of physical and biological sciences spanning hydrology and geochemistry to microbial and community ecology.
One approach to studying ecosystems is to divide the landscape into small watersheds, which enables input and output budgets for solutes to be constructed. Such budgets can constrain the the problem of comprehending and quantifying mechanisms operating in the ecosystem. The hydrochemistry and biogeochemistry of small watersheds are the subject of “Comparative Analyses of Small Watersheds,” session H-16 of the Fall Meeting.