Soil properties rather than plant production strongly impact soil bacterial community diversity along a desertification gradient on the Tibetan Plateau

Abstract

Grassland desertification is an important environmental issue that has detrimental impacts on the sustainable development of grasslands and human residential environments. Soil microbial community structure might dramatically change during desertification processes because microorganisms are one of the major drivers of ecological processes through their interactions with plants and soil. However, knowledge on the driving factors of microbial diversity changes during the desertification process in alpine grasslands is still lacking. Using a spatial sequence instead of a time successional sequence method, five desertification gradients in alpine steppe were chosen to investigate the changes in soil properties, plants and microbial communities during grassland desertification and to determine the factors that drive microbial community changes. Community coverage, species diversity indices and aboveground biomass gradually decreased from potential to severely heavy desertification gradients (HDs), while species richness and belowground biomass showed unimodal patterns (p < .05). Soil water content and total nitrogen showed gradual decreasing trends, while soil bulk density and gravel content showed opposite trends (p < .05). In addition, both the Shannon diversity index and the Chao1 richness index of soil bacteria increased gradually. The structural equation model showed that of the factors, soil total nitrogen (82.3% of total effect) and soil bulk density (41.4% of total effect) were the most important soil factors affecting soil bacterial diversity. However, community aboveground (43.4% of total effect) and belowground production (13.9% of total effect) were not the primary factors affecting soil microbial diversity. This result suggests that soil microbial diversity during grassland desertification is primarily driven by changes in soil properties, and the effects of vegetation composition and production are relatively small. These findings contribute to the mechanistic understanding of soil microbial diversity by linking changes in soil properties and plant production during desertification processes in alpine ecosystems.

Plant and Soil Microbial Diversity Co-Regulate Ecosystem Multifunctionality during Desertification in a Temperate Grassland

“…This finding was consistent with studies conducted in arid and semiarid grasslands, which have reported that desertification significantly reduced many ecosystem functions, including productivity and nutrient storage [16,31]. Firstly, the decrease in soil clay content in the desertified grasslands leads to a reduction in soil nutrients as soil organic matter is combined with soil fine fractions [41]. Secondly, desertification-induced loss of water and nutrients ultimately leads to limited plant productivity [42].…”

Variations in the diversity of the soil microbial community and structure under various categories of degraded wetland in Sanjiang Plain, northeastern China

“…During the process of SOM decomposition and nutrition cycling, Acidobacteria were higher in a degraded wetland than in a natural wetland (Eichorst et al, 2018), which corresponds to the results of the present study. This indicates that the relative abundance of Acidobacteria in PF, CL, and MW was higher than that in SW. Acidobacteria also contain a large number of oligotrophs (Zong & Shi, 2020). In degraded wetland soil with low organic matter content, the relative abundance of Acidobacteria was high (Peralta et al, 2013), which may be beneficial for the growth of oligotrophs.…”

Remediation Agents Drive Bacterial Community in a Cd-Contaminated Soil

“…Overall, planting sweet sorghum had weaker effects on soil bacterial community diversity and richness than SRAs. One possible reason may be that SRAs caused more significant changes in soil properties, which generally impact soil bacterial community diversity more strongly than plants [ 60 ].…”