Distinct microbial communities in the active and permafrost layers on the Tibetan Plateau

Abstract

Permafrost represents an important understudied genetic resource. Soil microorganisms play important roles in regulating biogeochemical cycles and maintaining ecosystem function. However, our knowledge of patterns and drivers of permafrost microbial communities is limited over broad geographic scales. Using high-throughput Illumina sequencing, this study compared soil bacterial, archaeal and fungal communities between the active and permafrost layers on the Tibetan Plateau. Our results indicated that microbial alpha diversity was significantly higher in the active layer than in the permafrost layer with the exception of fungal Shannon-Wiener index and Simpson's diversity index, and microbial community structures were significantly different between the two layers. Our results also revealed that environmental factors such as soil fertility (soil organic carbon, dissolved organic carbon and total nitrogen contents) were the primary drivers of the beta diversity of bacterial, archaeal and fungal communities in the active layer. In contrast, environmental variables such as the mean annual precipitation and total phosphorus played dominant roles in driving the microbial beta diversity in the permafrost layer. Spatial distance was important for predicting the bacterial and archaeal beta diversity in both the active and permafrost layers, but not for fungal communities. Collectively, these results demonstrated different driving factors of microbial beta diversity between the active layer and permafrost layer, implying that the drivers of the microbial beta diversity observed in the active layer cannot be used to predict the biogeographic patterns of the microbial beta diversity in the permafrost layer.

Permafrost thawing exhibits a greater influence on bacterial richness and community structure than permafrost age in Arctic permafrost soils

“…Our results demonstrated that nitrogen and the C:N ratio explained a greater proportion of the bacterial community structure than TOC. This is consistent with the previous findings that nitrogen availability strongly regulates microbial community structure and function in the permafrost soils of Arctic and Tibetan Plateau (Chen et al, 2018;Chen et al, 2017;Yergeau et al, 2010). Significantly different soil carbon and nitrogen were observed among the various permafrost thawing statuses, but not among the different permafrost ages (Figs.…”

“…The bacteria richness was significantly higher in the active layer soil (Fig. 2a), and this is consistent with the previous findings that permafrost thawing significantly increases bacterial richness in soil in the Tibetan Plateau and the high Arctic (Chen et al, 2017;Schostag et al, 2019;Wu et al, 2018).…”

High soilpHenhances the network interactions among bacterial and archaeal microbiota in alpine grasslands of the Tibetan Plateau

“…Soil microorganisms play an indispensable role in mediating the biogeochemical cycles of nutrient elements, such as C, N, S and P, and in maintaining ecosystem functions and services (Falkowski et al ., 2008; Wagg et al ., 2014; Chen et al ., 2017). Microorganisms in complex soil matrices are generally structured and form complex interconnected microbial networks (Barberán et al ., 2012; Ma et al ., 2016; Shi et al ., 2016; Morriën et al ., 2017; de Vries et al ., 2018; Banerjee et al ., 2019), where microbes interact through multiple processes, including competition, facilitation and inhibition.…”

Revealing Fungal Communities in Alpine Wetlands through Species Diversity, Functional Diversity and Ecological Network Diversity

“…They are important components of material cycling and energy flow in the ecosystem. They are widely distributed in various terrestrial environments such as forests [2,3], grasslands [4,5], hot springs [6,7], permafrost [8,9] and marsh wetlands [10,11]. Fungi have different species composition and distribution patterns in diverse habitats, thus forming complex fungal communities [12][13][14][15][16].…”