Efeitos das características do uso e cobertura do solo da bacia de drenagem sobre a qualidade da água e biodiversidade de ecossistemas aquáticos

Abstract

Proportions of different types of land use in the vicinity of aquatic systems have been widely used as predictors of water quality. Our goal was to test whether: i. biodiversity and quality of water reservoirs and coastal lagoons are negatively affected by anthropogenic modifications to the land use of their surroundings ; ii. the effects of land use on biodiversity and water quality in aquatic ecosystems are stronger in relation to the proximity such transformations occur; iii. different land uses will have different effects over water quality of aquatic environments. For this, 100 aquatic environments distributed in two regions (humid and semiarid areas) were sampled. To define the types of land use, classifications were made at different scales (buffer 50, 100, 250, 500) around aquatic environments. Overall, the best models were found for the land use in the 500m around the lakes. We found a positive relationship between the types of land use resulting from anthropogenic activities (exposed soil, pasture and urban area) and chemical indicators nitrogen (R² = 0.225, p < 0,05 ), phosphorus (R² = 0.291 , p < 0,05 ) and biological (R² = 0.343 , p < 0,05 ) from the trophic state. In regions of higher rainfall, turbidity and depth of the environments are better, also influencing water quality. In lakes more populated by native vegetation (Caatinga and Atlantic Forest), greater zooplankton richness (p < 0.05 R² = 0,217) was found. Shallow water environments can be further affected by specific matrices that modify the landscape and also be a model system to help reveal the overall relationship between the species diversity with different land uses.