Much remains to be learned about biological diversity, which constitutes a valuable natural resource. Due to the pressure that human activity has put on natural resources, biodiversity has been reduced, often unbeknownst to those responsible for that activity. Therefore, we aimed to perform a quantitative and qualitative analysis of periphytic algae in the Itupararanga reservoir, correlating the results with the physical and chemical characteristics of the water, as well as with climatic conditions. To that end, five samples were collected at four sampling stations in the Itupararanga reservoir during the year 2010. Aquatic macrophytes were collected with a 156-cm 2 frame, and the periphytic algae were scraped free of the macrophytes with a brush. Samples were fixed in formaldehyde and Lugol's solution for the qualitative and quantitative analyses, respectively. We identified 156 taxa belonging to eight classes, and the overall density was 10,200-171,800 individuals/mm 2 . The taxonomic composition and abundance of periphyton were found to be dependent on spatial and temporal factors, such as the type of substrate and the characteristics of the sampling site, as well as seasonal variations in the chemical and physical properties of the water.

Biomass and elemental composition (C, N, H) of the periphytic community attached to Polygonum punctatum Ell. in a subtropical reservoir and its relationship to environmental factorsThe periphytic communities in Brazilian reservoirs have been studied widely due to their importance for the assimilation of nutrients and their role at the base of the food chain. The objective of the present work was to analyse the environmental variables that influence the development of periphytic communities attached to stalks of the aquatic macrophyte Polygonum punctatum Ell. Five sample collections were made during 2010 at two sites in the Itupararanga reservoir (Ibiúna, São Paulo, Brazil). The macrophyte was collected, and the periphytic community attached to its stalks was scraped off with a brush and jets of distilled water. Using a PLS analysis, we observed that 94.3 % of the variation in periphyton biomass could be explained by concentrations of nitrate, conductivity, dissolved oxygen, water clarity and dissolved inorganic phosphorous. According to the indices applied, in 2010 the biomass of the periphytic community in the reservoir was low and predominantly heterotrophic, and the concentration of carbon in the periphyton was lower than that found in previous studies of this community.

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O campus da Universidade Federal de São Carlos do município de Sorocaba é composto por um remanescente florestal caracterizado por vegetação de mata estacional semidecidual e cerrado. Foram encontradas 96 espécies de briófitas na área: 56 musgos (sendo Fissidentaceae a família mais rica, com 11 spp.) e 40 hepáticas (sendo Lejeuneaceae a mais representativa, com 21 spp.). Oito espécies são endêmicas do Brasil e duas foram citadas pela primeira vez no Estado de São Paulo (Fissidens allionii Broth. e Lejeunea subsessilis Spruce). O predomínio de espécies corticícolas e da forma de vida em tapete indicam a forte relação com as condições microclimáticas do ambiente, assim como a disponibilidade de substrato. A presença simultânea de espécies da Mata Atlântica e do Cerrado indica uma área de transição, ao mesmo tempo que espécies de ampla distribuição, subcosmopolitas e ruderais expressam o caráter secundário do remanescente florestal.

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