Polypore communities and their substrate characteristics in Atlantic forest fragments in southeast Brazil

Abstract

Anthropogenic environmental changes have resulted in biodiversity crisis. Although tropical rainforests are one of the global biodiversity hotspots, their biodiversity is still poorly known. Especially fungi are poorly represented in national Red Lists and conservation plans, despite their important role in ecosystem functioning. We studied wood-inhabiting fungi (polypores) in four areas within two Atlantic rainforest fragments in Southeast Brazil. Our aim was to investigate fungal substrate characteristics and community composition. Deadwood amount ranged from 27 to 82 m3/ha among the four study areas and altogether we recorded 53 polypore species. More species were observed in intermediate and late decay stages than in early decay stages, but other deadwood variables did not explain the occurrence of polypores. Similarity in polypore community composition within and among the areas was low. Dissimilarity originated mostly from species turnover from a transect and area to another, and no nestedness in species occurrence pattern was detected. Hence, the observed dissimilarity in community composition was probably a result of heterogeneity in forest composition and structure, instead of environmental gradients or substrate limitations. These results corroborate previous polypore studies from the Atlantic forest in that tropical polypores are specialists toward particular decay stages. To develop ecologically effective conservation program for tropical polypores, more studies are needed on their distribution and abundance globally.