Office of Environment and Heritage, c/o School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, 2052, Australia.
Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, 2052, Australia.
Ecology. 2017 Jul;98(7):1922-1931. doi: 10.1002/ecy.1879. Epub 2017 Jun 12.
Scientists have largely neglected the effects of grazing on soil microbial communities despite their importance as drivers of ecosystem functions and services. We hypothesized that changes in soil properties resulting from grazing regulate the diversity of soil microbes by releasing/suppressing subordinate microbial taxa via competition. To test this, we examined how intensity of vertebrate herbivores influences the diversity and composition of soil bacteria and fungi at 216 soil samples from 54 sites across four microsites. Increasing grazing intensity reduced soil carbon, suppressing the dominant bacterial phylum Actinobacteria (indirectly promoting bacterial diversity) and increasing the dominant fungal phylum Ascomycetes (indirectly reducing fungal diversity). Our data provide novel evidence that grazing modulates the diversity and composition of soil microbes via increases or reductions in competition by dominant taxa. Our results suggest that grazing can potentially alter soil function by altering microbial community composition, providing a clear link between grazing management, carbon availability and ecosystem functions.
尽管食草作用对生态系统功能和服务具有重要意义，但科学家们在很大程度上忽视了其对土壤微生物群落的影响。我们假设，放牧导致的土壤性质变化通过竞争释放/抑制次要微生物类群来调节土壤微生物的多样性。为了验证这一点，我们在四个微生境的 54 个地点的 216 个土壤样本中，研究了脊椎动物食草动物的强度如何影响土壤细菌和真菌的多样性和组成。放牧强度的增加降低了土壤碳，抑制了优势细菌门放线菌（间接促进细菌多样性），并增加了优势真菌门子囊菌门（间接降低真菌多样性）。我们的数据提供了新的证据，表明放牧通过增加或减少优势类群的竞争来调节土壤微生物的多样性和组成。我们的结果表明，放牧可以通过改变微生物群落组成来改变土壤功能，为放牧管理、碳供应和生态系统功能之间提供了明确的联系。
