Long-term regional evidence of the effects of livestock grazing on soil microbial community structure and functions in surface and deep soil layers

Grazing by livestock can affect plant biodiversity and topsoil functions. However, experimental evidence on whether these impacts are limited to the or penetrate into deep layers (via changes in soil environment resource locations) of is lacking, especially for microbial biomass diversity. Here, we used paired grazed ungrazed (fenced) plots at 10 locations across Mongolian Plateau investigate how long-term (>10 years) grazing affects biomass, diversity, composition, function communities surface (0–20 cm) (40–60 cm). Livestock increased bacterial diversity 5–9% both but fungal 10% only topsoil. also strongly altered community composition layers. decreased C mineralization rates 11–25% layers, N 16% 20% The grazing-induced increase was mainly explained C:N ratio rather than abiotic variables, layer. negative effects ecosystem functions (soil mineralization) were associated with variables together layer Overall, our regional field experiment provides first that strong arid semi-arid grasslands. This knowledge suggests models should consider dynamic interactions between land use depths global drylands. Conceptual diagram showing structure Mongolia Plateau. We investigated large herbivore diversities using Our results provide a findings suggest • soils. bacteria stronger fungi depths. microbes deeper