This Special Issue of Water, Air, and Soil Pollution offers original contributions from BIOGEOMON, The Third International Symposium on Ecosystem Behavior, which was held on the campus ofVillanova University from June 21-25, 1997. Previous meetings were held in Prague in 1987 and again in 1993. The BIOGEOMON series was initiated in 1987 when a group of researchers from the Czech Geological Survey organized a conference called GEOMON, Geochemical Monitoring in Representative Basins. GEOMON was fairly narrowly focused on monitoring of element pools and fluxes on a small watershed scale. As...