Grazing intensity significantly changes the C:N:P stoichiometry in grassland ecosystems

 

Aim: Livestock grazing can alter carbon (C), nitrogen (N) and phosphorus (P) cycles, thereby affecting the C:N:P stoichiometry in grasslands. In this study, we aimed to examine the underlying mechanisms for the impacts of grazing intensity on grassland C:N:P stoichiometry, especially for the belowground processes and their linkages with aboveground vegetation properties.
Location: Global.
Time period: 1900-2018.
Major taxa studied: Grassland ecosystems.
Methods: Here, we conducted a meta-analysis based on 129 published studies to synthesize the effects of grazing on the C:N:P stoichiometry of leaves, stems, litter, roots, microbial biomass, and soil in grassland ecosystems.
Results: Grazing significantly affected the C, N and P pools, and then the C:N:P stoichiometry in grassland ecosystems. Grazing effects on C:N:P stoichiometry varied strongly with grazing intensity. Specifically, heavy grazing decreased all C:N:P stoichiometry except litter N:P and root C:N ratios, while li...

研究目的：家畜放牧可改变碳（C）、氮（N）与磷（P）循环过程，进而影响草地生态系统的碳氮磷化学计量比（stoichiometry）。本研究旨在解析放牧强度对草地碳氮磷化学计量比产生影响的潜在机制，重点关注地下过程及其与地上植被特征的关联。
研究区域：全球范围。
时间跨度：1900-2018年。
研究对象类群：草地生态系统（Grassland ecosystems）。
研究方法：本研究基于129项已发表的研究开展荟萃分析（meta-analysis），综合分析放牧对草地生态系统中叶片、茎秆、枯落物、根系、微生物生物量以及土壤的碳氮磷化学计量比的影响。
研究结果：放牧显著影响了草地生态系统中的碳、氮、磷库，进而改变其碳氮磷化学计量比。放牧对碳氮磷化学计量比的影响随放牧强度差异呈现显著分化。具体而言，重度放牧会降低除枯落物氮磷比（litter N:P）与根系碳氮比（root C:N）之外的所有碳氮磷化学计量比指标，而li...