Efeito do aquecimento e uso da terra sobre a biomassa e composição de algas e cianobactérias perifíticas.

Abstract

Aquatic environments are impacted by global changes, primarily driven by human activities such as temperature increases, land use changes, and eutrophication. Periphyton, mainly composed of algae and cyanobacteria, plays a crucial role in the structure and functioning of aquatic ecosystems by contributing to primary production, nutrient cycling, and serving as a bioindicator of water quality. This study experimentally investigated, using mesocosms and artificial substrates, the effects of warming and land use (nutrient input and reduced detritus input) on the biomass (GLMM) and composition (PERMANOVA and IndVal) of the periphytic community. A total of 61 taxa were recorded. As expected, warming and land use affected the periphytic composition and biomass. The isolated and combined effects of temperature, eutrophication, and reduced detritus input were observed. Filamentous green algae and cyanobacteria showed higher biomass. Thus, warming and land use drive changes in the structure of the periphytic community, favoring more tolerant forms and taxonomic groups. The periphyton proved to be sensitive to the effects of temperature and land use, reinforcing its role as a bioindicator of climate change and eutrophication in aquatic environments.