Outcall: Hotel and home visits
You must be logged in to view this content. Please click the button below to log in.Login
Seasonal variation of limnological features and trophic state index of two oligotrophic reservoirs of southeast Brazil. Oliveira a. Limnological features of two reservoirs were studied in dry August and rainy January periods to evaluate the water quality that supply the city of Guarulhos, southeast Brazil. Water samples were collected in three depths and the following characteristics were measured: alkalinity, dissolved O 2 , free and total CO 2 , HCO 3 , soluble reactive silica, dissolved and total nitrogen and phosphorus, and chlorophyll- a. Water transparency was also measured and temperature, pH and electric conductivity profiles were obtained. Great seasonal and low spatial variability of the water characteristics occurred in the reservoirs. High values of water transparency, free CO 2 availability, and low of pH, soluble reactive silica and total and dissolved nutrients values were recorded at the dry period, and different conditions were found at the rainy season. The two reservoirs were characterized by low nutrients, chlorophyll- a and turbidity, and high transparency, these features being typical of oligotrophic systems. The need for actions that will reduce the input of nutrients from the neighboring cities and the main tributaries of the hydrographic basin is emphasized to maintain the ecological quality of the reservoirs and their reference conditions among the SPRM reservoirs.
De Entre e o cerrado brasileiro, por exemplo, perdeu cerca de Panorama da Biodiversidade Global 3 , , p. In: Global Biodiversity Outlook 1 , In: Millennium Ecosystem Assessment Board. The Millennium Ecosystem Assessment Series.