Environmental factors influencing the phyllosphere eukaryotic algal community

(1) Phyllosphere algae are common in tropical rainforests, forming visible biofilms or spots on plant leaves surface. Classical morphological approach can hardly provide a detailed inventory of phyllosphere eukaryotic algal diversity. Our knowledge of these communities and their impact factors is also limited. So we investigated the phyllosphere eukaryotic algal diversity and did the first exploration of environmental factors influencing the phyllosphere eukaryotic algal community in XiShuangBanNa Tropical Botanical Garden, Yunnan, China.(2) Forty-eight samples were collected from three areas, four host trees from each area in four months during 2018 to 2019. Single Molecule Real-Time sequencing was used to obtain the environmental 18S full-length sequences.(3) There were 304 algal OTUs obtained in total, with 94% unknown OTUs. Watanabeales and Trentepohliales dominate in almost all samples. Species richness and biomass of artificial forest were lower than primeval and reserve rainforest. Community composition of artificial forest and primeval rainforest were significantly different. Host tree species, SRP, TN and NH4+-N also affected the algal community to some extent.(4) The eukaryotic algal community structures were significantly related with forest types and host species. It allowed of no delay to protect tropical rainforests to protect biodiversity.