Effects of different management practices on soil microbial community structure and function in alpine grassland

Area of Science:

• Ecology
• Soil Science
• Microbiology

Background:

• Grassland degradation is a significant environmental issue.
• Management practices like grazing exclusion and reseeding are used to mitigate degradation.
• The impact of these practices on soil microbial communities in the Qinghai Tibetan Plateau (QTP) is not well understood.

Purpose of the Study:

• To evaluate the effects of various grassland management practices on soil microbial community structure and function in the QTP.
• To provide a reference for assessing and improving ecosystem functions under different management strategies.

Main Methods:

• Investigated impacts of grazing (exclusion, seasonal, traditional), reseeding (annual oat, perennial artificial), and integrated restoration (weed control, no-tillage reseeding).
• Analyzed soil microbial community structure (e.g., Shannon-Wiener diversity, relative abundance of specific phyla) and function (e.g., pathotrophs, saprotrophs).
• Correlated microbial changes with soil properties (water content, plant biomass, C:N ratio).

Main Results:

• Annual oat reseeding (RO) showed highest prokaryotic diversity; integrated restoration showed highest fungal diversity.
• Seasonal grazing increased Actinobacteria abundance but also plant pathogens.
• Integrated restoration had higher Betaproteobacteria, Alphaproteobacteria, and Deltaproteobacteria, and lower Thermoleophilia.
• Grazing management influenced pathotroph and saprotroph proportions, while integrated restoration significantly increased pathotrophs compared to grazing exclusion.

Conclusions:

• Management practices significantly alter soil microbial community structure and function in the QTP, primarily by modifying soil nutrient profiles.
• Specific grazing types can attract certain microbes (pathotrophs, saprotrophs) while repelling others (plant pathogens).
• Consideration of soil microbial community modulations is crucial for effective grassland degradation management planning.