Seasonal and Spatial Variability of Nutrients in Tropical Streams Due to Anthropogenic Activities A case study in a Brazilian rain forest reserve (original) (raw)

The Parque Estadual Turistico do Alto Ribeira (PETAR) is an Atlantic rain forest reserve in South-eastern Brazil. A few small villages are located inside the watersheds of the three main rivers that cross the park, Betari, Iporanga and Piloes. Untreated domestic sewage from households is often discharged directly into the watercourses. Subsistence agriculture is practiced by most of those families, which adds nutrients to the stream due to increased soil erosion. Additionally, larger farms located near the headwater of PETAR rivers use fertilizers to improve soil condition. The main goal of this study is to investigate seasonal and spatial variability in nutrient concentration in PETAR watercourses due to inputs from human settlements and agricultural areas within or near the park. Twenty-one sites located in fifteen streams were surveyed during field campaigns carried on in June and November 1998. Nitrogen and phosphorus concentration, as well as other physical and chemical water p...