| Urbanization and agriculture alter expressively the physical and chemical variables of lotic habitats, especially streams, causing negative effects to the biota of these environments. This study aimed to (i) evaluate the spatial and seasonal variations in the structure of periphytic diatom assemblage in a stream under urban influence in its headwaters, and rural influence, in the rest of its course, and (ii) select diatom species as bioindicators of urban and rural stretches. Three sampling sites were set along the stream according to its longitudinal gradient. The structure of the periphytic diatom assemblage presented differences in spatial scale, differing substantially between the urban and rural habitats. There was a higher influence of nutrients... |
