Diversity and assembly processes of microbial eukaryotic communities in Fildes Peninsula Lakes (West Antarctica)

[摘要] The diversity, co-occurrence patterns, and assembly processes of microbialeukaryotes (0.2–20  µ m) in Antarctic freshwater lakes are not wellunderstood, despite their wide distribution and ecological importance. Thisstudy used Illumina high-throughput sequencing to investigate the microbialeukaryotic communities of five freshwater lakes on the Fildes Peninsula overthree summer seasons. A total of 28 phyla were detected, with phytoplanktonoccupying the highest percentage of sequences (accounting for up to 98 %).The dominant taxa consisted of Chrysophyta, Chlorophyta, and Cryptophyta.The species richness (113–268) and Shannon index (1.70–3.50) varied amongthe lakes, with higher values recorded in Lake Chang Hu and Lake Kitec andthe lowest value obtained for Lake Yue Ya. There were significantdifferences between the microbial eukaryotic communities of the lakes, withspatial and temporal heterogeneity in the relative abundance of thedominant taxa ( P <0.05 ). Environmental variables explained about39 % of the variation in community structures, with water temperature andphosphate identified as the driving factors ( P <0.05 ). Networkanalysis revealed comprehensive co-occurrence relationships (positivecorrelation 82 % vs. negative correlation 18 %). The neutral communitymodel revealed that neutral processes explained more than 55 % of thecommunity variation. Stochastic processes (e.g. homogenizing dispersal andundominated processes) predominated in community assembly over thedeterministic processes. These findings demonstrate the diversity of themicrobial eukaryotic communities in the freshwater lakes of the FildesPeninsula and have important implications for understanding the communityassembly in these ecosystems.

[学科分类] 大气科学