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The effects of different intensities of long-term grazing on the direction and strength of plant–soil feedback in a semiarid grassland of Northwest China

Chen, Tao, Christensen, Michael, Nan, Zhibiao, Hou, Fujiang
Plant and soil 2017 v.413 no.1-2 pp. 303-317
Artemisia capillaris, Fusarium tricinctum, Lespedeza daurica, Stipa bungeana, arid lands, fungal communities, grasslands, grazing intensity, mycorrhizal fungi, nitrogen, nutrient availability, nutrient content, perennials, phytomass, soil, soil nutrients, soil sterilization, soil-plant interactions, China
AIMS: Plant–soil feedbacks (PSFs) and grazing drive community dynamics in grasslands. We examined how the intensity of grazing and PSF interact to affect plant growth and explored what drives the observed feedback effects. METHODS: Three dominant perennial plant species; Artemisia capillaris, Lespedeza davurica, and Stipa bungeana were grown in field-conditioned soil (sterilized or unsterilized) collected from four grazing intensities in a semiarid grassland of northwest China. Soil nutrient concentrations and root fungal communities were determined. RESULTS: Plant biomass increased with grazing intensity for the three plant species. Within each grazing intensity, plant growth in sterilized soil relative to unsterilized soil differed markedly among species. Soil inorganic nitrogen (N) concentration tended to increase with increasing grazing intensity. Arbuscular mycorrhizal fungi (AMF) colonization was high for all grazing intensities for L. davurica. Fusarium tricinctum, the most common pathogenic Fusarium species, had the highest frequency from the control for A. capillaris and tended to increase with increasing grazing intensity for S. bungeana. CONCLUSIONS: Our results suggest that in grasslands plant growth can be modified by the intensity of grazing via grazing-induced changes in soil nutrient availability and fungal communities. Additional studies are needed to determine how grazing intensity affects species co-existence through PSFs to mixed communities.