Soil Water Content Shapes Microbial Community Along Gradients of Wetland Degradation on the Tibetan Plateau.

Xiaoming Kang,Kerou Zhang,Zhongqing Yan,Liang Liu,Enze Kang,Meng Li

doi:10.3389/fmicb.2022.824267

Abstract

Soil microbes are important components in element cycling and nutrient supply for the development of alpine ecosystems. However, the development of microbial community compositions and networks in the context of alpine wetland degradation is unclear. We applied high-throughput 16S rRNA gene amplicon sequencing to track changes in microbial communities along degradation gradients from typical alpine wetland (W), to wet meadow (WM), to typical meadow (M), to grassland (G), and to desert (D) in the Zoige alpine wetland region on the Tibetan Plateau. Soil water content (SWC) decreased as wetland degradation progressed (79.4 and 9.3% in W and D soils, respectively). Total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP) increased in the soils of WM, and then decreased with alpine wetlands degradation from WM to the soils of M, G, and D, respectively. Wetland degradation did not affect microbial community richness and diversity from W soils to WM, M, and G soils, but did affect richness and diversity in D soils. Microbial community structure was strongly affected by wetland degradation, mainly due to changes in SWC, TOC, TN, and TP. SWC was the primary soil physicochemical property influencing microbial community compositions and networks. In wetland degradation areas, Actinobacteriota, Acidobacteriota, Cholorflexi, and Proteovacteria closely interacted in the microbial network. Compared to soils of W, WM, and M, Actinobacteriota played an important role in the microbial co-occurrence network of the G and D soils. This research contributes to our understanding of how microbial community composition and networks change with varied soil properties during degradation of different alpine wetlands.

Highlights

Soil microbes play a vital role in many ecological processes of wetlands and are essential for maintaining ecosystem functions and stability (Wu et al, 2021)
At the five sites in the study area Na Ruoqiao (NRQ), Neng Wa (NW), Ling Ga (LG1 and LG2), and Hua Hu (HH), sampling plots were selected with five gradients of wetland degradation at each site: typical wetland (W), wet meadow (WM), meadow (M), grassland (G), and desert (D) (Figure 1)
Soil water content (SWC) decreased along the wetland degradation from 79.4% on average in the W soils to 56.2% in the WM soils, 40.7% in the M soils, 29.4% in the G soils and 9.3% in the D soils (Table 1)

Summary

Introduction

Soil microbes play a vital role in many ecological processes of wetlands and are essential for maintaining ecosystem functions and stability (Wu et al, 2021). The microbial community is closely associated with ecological functioning of soil microbes, because of the diverse functions provided by the different microbial species (Crowther et al, 2019). Microbial Community Along Wetland Degradation of microbial communities has a positive impact on element cycling, nutrient uptake, organic matter decomposition, and toxin removal (Tang et al, 2011; Wu et al, 2015). The soil microbial community is sensitive to variation in soil physicochemical properties and can serves as an indicator of soil quality (Yu et al, 2012; Wu et al, 2021). Changes in microbial community can provide feedback to ecosystem functions and may offer an opportunity to mitigate the impact of ecosystem alterations induced by human disturbance and environmental variation (Huang et al, 2020)

Methods

Results

Conclusion