| Title: | Grazing simplifies soil micro-food webs and decouples their relationships with ecosystem functions in grasslands |
| Author(s): | Wang B; Wu L; Chen D; Wu Y; Hu S; Li L; Bai Y; |
| Address: | "State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China. University of Chinese Academy of Sciences, Beijing, China. College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot, China. College of Biological and Pharmaceutical Sciences, China Three Gorges University, Yichang, China. Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China. Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, NC, USA" |
| ISSN/ISBN: | 1365-2486 (Electronic) 1354-1013 (Linking) |
| Abstract: | "Livestock grazing often alters aboveground and belowground communities of grasslands and their mediated carbon (C) and nitrogen (N) cycling processes at the local scale. Yet, few have examined whether grazing-induced changes in soil food webs and their ecosystem functions can be extrapolated to a regional scale. We investigated how large herbivore grazing affects soil micro-food webs (microbes and nematodes) and ecosystem functions (soil C and N mineralization), using paired grazed and ungrazed plots at 10 locations across the Mongolian Plateau. Our results showed that grazing not only affected plant variables (e.g., biomass and C and N concentrations), but also altered soil substrates (e.g., C and N contents) and soil environment (e.g., soil pH and bulk density). Grazing had strong bottom-up effects on soil micro-food webs, leading to more pronounced decreases at higher trophic levels (nematodes) than at lower trophic levels (microbes). Structural equation modeling showed that changes in plant biomass and soil environment dominated grazing effects on microbes, while nematodes were mainly influenced by changes in plant biomass and soil C and N contents; the grazing effects, however, differed greatly among functional groups in the soil micro-food webs. Grazing reduced soil C and N mineralization rates via changes in plant biomass, soil C and N contents, and soil environment across grasslands on the Mongolian Plateau. Spearman's rank correlation analysis also showed that grazing reduced the correlations between functional groups in soil micro-food webs and then weakened the correlation between soil micro-food webs and soil C and N mineralization. These results suggest that changes in soil micro-food webs resulting from livestock grazing are poor predictors of soil C and N processes at regional scale, and that the relationships between soil food webs and ecosystem functions depend on spatial scales and land-use changes" |
| Keywords: | Animals Biomass *Ecosystem Food Chain Grassland Herbivory *Soil Mongolian Plateau functional groups livestock grazing soil carbon mineralization soil environment soil nitrogen mineralization soil substrates trophic levels; |
| Notes: | "MedlineWang, Bing Wu, Liji Chen, Dima Wu, Ying Hu, Shuijin Li, Linghao Bai, Yongfei eng 2015061/Youth Innovation Promotion Association of the Chinese Academy of Sciences/International 31570450/National Natural Science Foundation of China/International 31630010/National Natural Science Foundation of China/International 2016YFC0500804/Chinese National Key Development Program for Basic Research/International England 2019/09/19 Glob Chang Biol. 2020 Feb; 26(2):960-970. doi: 10.1111/gcb.14841. Epub 2019 Oct 1" |
