Livestock and Burrowing Mammals Have Contrasting Impacts on Soil Infiltration of Grasslands

The role of the increasing rodent population in grassland degradation on the Qinghai–Tibet Plateau (QTP) is the subject of continuing debate. Rodenticides are used to control the population, but this measure threatens ecosystem biodiversity. We conducted a five-year grazing experiment to investigate the response of soil permeability to livestock grazing and subterranean plateau zokor ( Myospalax baileyi ) in grasslands. Using a meta-analysis approach, we generalized the effects of livestock grazing and others burrowing mammals on soil permeability in global grasslands. The objective was to test the hypothesis that underground soil disturbance by burrowing mammals helps to improve the permeability of soil that has been compacted by trampling from grazing livestock. We found that soil saturated hydraulic conductivity (Ks) in the upper 10 cm layer under livestock grazing was one half of that under no grazing in zokor-excluded plots. The Ks value on zokor mounds (> two years old) was eight times greater than that of inter-mound areas in livestock-grazed plots. These contrasting effects on soil permeability of livestock grazing and subterranean zokor disturbance were ascribed to their opposite effects on soil macroporosity. Meta-analysis confirmed a global generality of decreased Ks and steady infiltration rate in grazed compared with non-grazed grasslands. However, we did not find any studies on the effect of mound-making and underground foraging by subterranean mammals such as zokors (which spend their whole life underground) on soil permeability in global grasslands. Our results provide a new perspective for understanding the ecological function of subterranean mammals in pastures. In the management of subterranean mammals in grazed grasslands, their beneficial effects on promoting soil permeability must be considered