Reply on RC1

Abstract

The diversity, co-occurrence patterns, and assembly processes of microeukaryotes in Antarctic freshwater lakes are not well understood, despite its wide distribution and ecological importance. This study used Illumina high-throughput sequencing to explore five freshwater lakes' microeukaryotic communities on the Fildes Peninsula during three summer seasons. A total of 33 phyla were detected, with the phytoplankton occupying the highest percentage of sequences (accounting for up to 98 %). Meanwhile, the main dominant taxa were Chrysophyta, Chlorophyta, and Cryptophyta. Alpha diversity varied among lakes, with Changhu (CH), Kitec (KT) lake having higher values, and Yue Ya (YY) lake having the lowest value. There were significant differences in microeukaryotic communities between lakes, with spatial and temporal variation in the relative abundance of dominant taxa (P<0.05). Environmental variables only explained about 30 % of the variation in community structure. In the co-occurrence network, microeukaryotes tended to be more symbiotic than competitive with each other (positive correlation 82 % vs. negative correlation 18 %), with only 8 % of OTUs significantly associated with environmental factors. The neutral community model found that neutral processes explained more than 56 % of the community variation. The stochastic processes (e.g., homogenizing dispersal and undominated process) predominated in community assembly than the deterministic processes. These findings revealed the diversity of the microeukaryotic community and have important implications for understanding the community assembly in the freshwater lakes of the Fildes Peninsula (Antarctica).