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1. Epiphytic communities offer an original framework to disentangle the contributions of environmental filters, biotic interactions and dispersal limitations to community structure at fine spatial scales. We determine here whether variations in light, microclimatic conditions and host tree size affect the variation in species composition and phylogenetic structure of epiphytic bryophyte communities, and hence, assess the contribution of environmental filtering, phylogenetic constraints and competition to community assembly.2. A canopy crane giving access to 1.1 ha of tropical rainforest in Yunnan (China) was employed to record hourly light and microclimatic conditions from 54 dataloggers and epiphytic bryophyte communities from 408 plots. Generalized Dissimilarity Modelling was implemented to analyse the relationship between taxonomic and phylogenetic turnover among epiphytic communities, host-tree characteristics and microclimatic variation.3. Within-tree vertical turnover of bryophyte communities was significantly about 30% higher than horizontal turnover among-trees. Thus, the sharp vertical variations in microclimatic conditions from tree base to canopy are more important than differences in age, reflecting the likelihood of colonization, area, and

As a better understanding of Beijing surface water ecosystems can provide clues for environmental management and public health, here, we report a study of the bacterial communities of five Beijing surface waters conducted using 454 pyrosequencing of 16S ribosomal RNA (rRNA) genes. We expected to observe a core bacterial community among the surface waters and differences in bacterial community abundance over the different locations of sampling. In this study, we obtained a total of 60,810 trimmed reads from the five samples after the removal of unqualified reads. Bacterial sequences from the five samples were classified into taxonomic classes using the default settings of the mothur platform. Our results provided insight into the bacterial community composition of surface waters and revealed that there was a core microbial community in the microbial populations of surface samples at different geographic locations, with 13 phyla and 40 genera in common. Our findings also revealed the differences in bacterial communities among five surface water samples obtained at different locations.