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Dominant plants play crucial roles in supporting the functioning of terrestrial ecosystems. Plants can influence the spatial heterogeneity of environmental factors, as well as the spatial turnover in the composition of soil communities (i.e. β‐diversity of soil communities). However, we still poorly understand how dominant plants drive the spatial turnover in multiple ecosystem functions (β‐multifunctionality hereafter), and to which extent the effects of dominant plants are mediated by changes in environmental heterogeneity and the β‐diversity of soil communities.Antarctica supports one of the most challenging environments on the planet including low temperature and water availability. Here, we collected soil samples under three dominant plants (lichen, moss and vascular plants) and bare ground. We measured carbon storage, nutrient availability, nutrient decomposition, microbial biomass and pathogen control to calculate β‐multifunctionality.Both non‐vascular and vascular plants were associated with increased β‐multifunctionality compared to bare ground. We further showed that lichen mainly affected β‐multifunctionality through soil temperature heterogeneity and β‐bacterial diversity. Similarly, moss mainly affected β‐multifunctionality through the spatial heterogeneity of soil water content and β‐bacterial diversity. However, vascular plants did not significantly affect environmental heterogeneity. Instead, the responses of β‐multifunctionality to vascular plants were mainly driven by the β‐diversity of soil communities. These results indicate that environmental heterogeneity is important for turnover in multiple ecosystem functions in early successional stages (dominated by non‐vascular plants), while the importance of soil communities' heterogeneity becomes more significant in late successional stages (dominated by vascular plants).Synthesis. Our findings highlight the fundamental role of dominant plants in controlling the spatial turnover in ecosystem functions, and suggest that accelerated succession under current climate warming may increase bacterial β‐diversity but decrease abiotic heterogeneity, thereby leading to both increases (e.g. regarding functions related to microbial biomass) and decreases (e.g. regarding functions related to nutrient availability) in β‐multifunctionality and hence the spatial turnover in levels of ecosystem functioning. [ABSTRACT FROM AUTHOR]

The diversity, co-occurrence patterns, and assembly processes of microbial eukaryotes (0.2–20 µ m) in Antarctic freshwater lakes are not well understood, despite their wide distribution and ecological importance. This study used Illumina high-throughput sequencing to investigate the microbial eukaryotic communities of five freshwater lakes on the Fildes Peninsula over three summer seasons. A total of 28 phyla were detected, with phytoplankton occupying 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 among the lakes, with higher values recorded in Lake Chang Hu and Lake Kitec and the lowest value obtained for Lake Yue Ya. There were significant differences between the microbial eukaryotic communities of the lakes, with spatial and temporal heterogeneity in the relative abundance of the dominant taxa (P<0.05). Environmental variables explained about 39 % of the variation in community structures, with water temperature and phosphate identified as the driving factors (P<0.05). Network analysis revealed comprehensive co-occurrence relationships (positive correlation 82 % vs. negative correlation 18 %). The neutral community model revealed that neutral processes explained more than 55 % of the community variation. Stochastic processes (e.g. homogenizing dispersal and undominated processes) predominated in community assembly over the deterministic processes. These findings demonstrate the diversity of the microbial eukaryotic communities in the freshwater lakes of the Fildes Peninsula and have important implications for understanding the community assembly in these ecosystems. [ABSTRACT FROM AUTHOR]

Snow in Antarctica is a vast terrestrial ecosystem and plays a key role that has likely been underestimated. Algae are the key primary producers on the coloured snow surface, and they support a microbial community that includes bacteria, fungi and/or invertebrates. We analysed microbial communities that co-exist in green and red snow samples from the Fildes Peninsula by Illumina sequencing, Antarctica, as well as the influence of snow physicochemical properties. We detected several species of green algae from Chlorophyta and Ochrophyta as well as fungi and cercozoans. The three red snow samples (RS1, RS2 and RS3) were represented by mixed eukaryotic microalgae from Sanguina, Chloromonas and Trebouxiophyceae. The green snow sample GS5 exhibited lake-to-snow colonisation composed of Trebouxiophyceae, Ulvophyceae and Chrysophyta representatives. The red snow RS4, predominantly by Chlainomonas sp. from slush layers, which presented a different microbial community from the other red snow samples, was sampled close to green snow sample GS5 near Lake Changhu. The environmental parameters were involved into descriptive differences among these coloured snow samples. The two snow algae Chlainomonas and Sanguina were firstly reported from Antarctica, which indicates distinguished snow algae colonisation that is closely connected with the melting snow at the lake ice-cover. Meanwhile, consistent with previous bacterial community profiles, Proteobacteria and Bacteroidetes were mostly represented in all the coloured snow samples. Polaromonas (Betaproteobacteria) was the most abundant genus, and its presence was reportedly essential for the sustained growth of snow algae. Flavobacterium from Bacteroidetes was the most frequently detected genera in GS5, but the Sphingobacteriia with only a few reads were an interestingly minority in GS5. The snow-algae-associated bacteria were closely related to psychrophilic strains or sequences from low-temperature environments. Many possible factors influence on the coloured snow microbial communities would require attentions, to help understand their occurrence mechanisms, their biogeographic distributions in polar regions. [ABSTRACT FROM AUTHOR]