Distinct strategies of the habitat generalists and specialists in sediment of Tibetan lakes

Abstract

Microbial metacommunities normally comprise generalists and specialists. Uncovering the mechanisms underlying the diversity patterns of these two subcommunities is crucial for aquatic biodiversity maintenance. However, little is known about the ecological assembly processes and co-occurrence patterns of the habitat generalists and specialists across large spatial scales in plateau lake sediments, particularly regarding their environmental adaptations. Here, we investigated assembly processes of the habitat generalists and specialists in sediment of Tibetan lakes and their role in the stability of metacommunity cooccurrence network. Our results showed that the habitat generalists exhibited broader environmental thresholds and closer phylogenetic clustering than specialist counterparts. In contrast, the specialists exhibited stronger phylogenetic signals of ecological preferences compared with the habitat generalists. Stochastic processes dominated the habitat generalist (63.2%) and specialist (81.3%) community assembly. Sediment pH was the major factor mediating the balance between stochastic and deterministic processes in the habitat generalists and specialists. In addition, as revealed by network analysis, the habitat specialists played a greater role in maintaining the stability of metacommunity co-occurrence network. The insights gained from this study can be helpful to understand the mechanisms underlying maintenance of sediment microbial diversity in plateau lakes.

Patterns of bacterial generalists and specialists in lakes and reservoirs along a latitudinal gradient

“…Interestingly, in both bacterial taxa, stochastic processes were more dominant than deterministic ones (Figures 4 and S7). Previously, this has been also found for bacterial generalists and specialists of sediment bacteria of various Tibetan lakes (Yan et al, 2022). However, in farmland soil, generalists were dominated by stochastic processes, while specialists were driven mainly by deterministic processes (Xu, Luo, et al, 2022; Xu, Vandenkoornhuyse, et al, 2022).…”

Soil organic carbon loss decreases biodiversity but stimulates multitrophic interactions that promote belowground metabolism

“…A decline in SOC could precipitate substantial decreases, or depletion in extreme cases, in various organic fractions, leading to a reduction in diversity and compositional complexity of SOC molecules (Figure S15; Lehmann et al., 2020). In this case, specialized species that are dependent upon these organic compounds might be susceptible to extinction (Martinović et al., 2022; Slatyer et al., 2013; Yan et al., 2022), as corroborated by the observed decrease in the proportion of specialists residing in LC soils as compared to HC soils (Table S9). In particular, proteinaceous compounds were identified as the major fraction impacting biodiversity loss and community compositional shifts (Table S10 and Figure S16).…”

Host signature as major driver of root and rhizosphere core microbiomes that differently affect plant functional traits

“…These suggested that the endosphere microbiota was more resistant than the rhizosphere and bulk soil microbiota to such changes. Furthermore, the larger network sizes and higher complexity were observed for specialists than for generalists, indicating that the former may interact more frequently with each other than do the latter [77]. Similarly, the significantly higher values of betweenness centrality and eigenvector centrality for specialists than for generalists may suggest that specialists are more often located in central positions within the network than generalists (Additional Figure S8 and S9), and thus had a higher likelihood of becoming ‘hub microorganisms’ [78].…”