Biogeographic patterns of abundant and rare bacterial and microeukaryotic subcommunities in connected freshwater lake zones subjected to different levels of nutrient loading.

Abstract

To reveal whether the patterns of abundant and rare subcommunity composition of both bacteria and microeukaryotes vary between connected regions with different levels of nutrient loading in freshwater lakes. We investigated the abundant and rare subcommunity composition of both bacteria and microeukaryotes in two connected zones (Meiliang Bay (MLB) and Xukou Bay (XKB)) of a large shallow freshwater Lake Taihu via the high-throughput sequencing of bacterial 16S rRNA and microeukaryotic 18S rRNA genes. Even though these two lake zones are connected and share a species bank, they diverge in community composition. Significantly higher alpha diversity was observed for the abundant bacterial subcommunity in the MLB. However, no significant difference in alpha diversity between the rare bacterial subcommunities, as well as both rare and abundant microeukaryotic subcommunities were observed between MLB and XKB. It is demonstrated that both environmental factors and geographic distance play central roles in controlling the rare and abundant microbial subcommunities in the two connected lake zones. The abundant subcommunity composition of bacteria and microeukaryotes vary between connected regions with different levels of nutrient loading. Dispersal limitation plays a vital role in shaping microbial communities even in connected zones of freshwater lakes. Leading to a comprehensive understanding of the characteristics of microbial community in connected lake regions with different levels of nutrient loading.