Bryophyte flora in an Amazon island: structure of communities in areas of different levels of anthropization

Abstract

Abstract The present study is aimed to evaluate the richness, composition and spatial distribution of bryophytes occurring in Mosqueiro Island, in the Amazon forest. Forty-one 100-m² plots in 37 flooded and 4 non-flooded environments were selected for data collection, all substrate found were considered. The results were compared with surveys in other islands from the state of Pará and were analyzed according to frequency of populations, colonized substrates, light tolerance guilds, and distribution in Brazilian biomes. Ninety-seven species were recorded, distributed in 36 genera and 17 families, being 57 (58.7%) liverwort and 40 (41.2%) moss species. The rare species stood out with 53 species (54.08%). High similarity was observed between corticolous and epixylic communities, and between the terricolous community and the bryophytes found growing on charcoal, which is an artificial substrate. In relation to light tolerance guilds, generalist species prevailed (52 species, 53.6%). As for phytogeographic distribution, there was a predominance of taxa with occurrence in the Amazon and Atlantic rainforest (35 species, 37.11%). Ceratolejeunea ceratantha is reported for the first time for the state of Pará. The level of anthropization in the island was showed mainly by high richness and occurrence of generalist species underscores and well-adapted species to stressed conditions, evidencing changes in the bryophyte community structure.