Mi Jia, Wang Qianju, Ou Jun, Shi Jing, Pang Haiyan, Feng Ziheng, Bai Yongfei
Shanxi Key Laboratory for Ecological Restoration of Loess Plateau, Institute of Loess Plateau, Shanxi University, Taiyuan, China.
Field Scientific Observation and Research Station of the Ministry of Education for Subalpine Grassland Ecosystem in Shanxi, Ningwu, China.
Front Plant Sci. 2025 Jul 8;16:1597590. doi: 10.3389/fpls.2025.1597590. eCollection 2025.
Grazing and enclosure are two major grassland management techniques, which are used to preserve plant variety, productivity, and ecosystem function.
In order to compare plant diversity and ecosystem function under grazing and enclosure conditions, this study observed three typical grassland locations in southeast of Inner Mongolia via medium-scale line transect surveys.
Our results showed that soil nutrients in enclosed grasslands control the diversity of plant species and aboveground biomass (AGB), which in turn regulates the amount of belowground biomass (BGB) by allocation. Enclosure consistently enhanced AGB and plant height compared to grazing, while increasing the relative contribution of perennial grasses and forbs to productivity through functional group reorganization. However, biodiversity responses were site-specific, enclosure increased plant diversity at two sites but reduced it at another, revealing landscape-dependent results.
The grazing reshaped ecosystem regulation through three key changes: (1) the relationship between soil nutrients and AGB was inverted, and demonstrated a negative correlation between diversity and AGB, (2) established the trade-off of the effects of BGB on AGB driven by soil properties (soil nutrients and pH), (3) microbial community restructuring from dual nutrient-pH regulation to pH-dominated control and (4) grazing strengthened plant biomass-diversity linkages, while enclosure prioritized soil nutrient-plant diversity correlations. Crucially, grazing reversed the functional role of soil pH, from positive microbial community regulation in the enclosure area to negative effects, through soil microenvironment alteration. These results provided a framework in which management practices reorganize ecological networks. Enclosure strengthened soil nutrient-mediated plant-soil feedbacks, while grazing promoted pH-driven microbial selection and change of biomass allocation strategy. Meanwhile, the spatial variability of enclosure effects highlighted the importance of local environmental backgrounds for consequences of grassland management.
放牧和围栏封育是两种主要的草地管理技术，用于保护植物多样性、生产力和生态系统功能。
为了比较放牧和围栏封育条件下的植物多样性和生态系统功能，本研究通过中尺度样线调查对内蒙古东南部的三个典型草地位置进行了观测。
我们的结果表明，围栏封育草地中的土壤养分控制着植物物种多样性和地上生物量（AGB），而地上生物量又通过分配调节地下生物量（BGB）的数量。与放牧相比，围栏封育始终提高了地上生物量和植物高度，同时通过功能群重组增加了多年生禾本科植物和杂类草对生产力的相对贡献。然而，生物多样性响应具有地点特异性，围栏封育在两个地点增加了植物多样性，但在另一个地点降低了植物多样性，揭示了依赖景观的结果。
放牧通过三个关键变化重塑了生态系统调节：（1）土壤养分与地上生物量之间的关系发生反转，并表明多样性与地上生物量之间呈负相关，（2）建立了由土壤性质（土壤养分和pH值）驱动的地下生物量对地上生物量影响的权衡，（3）微生物群落从双养分-pH调节转变为以pH为主导的控制，以及（4）放牧加强了植物生物量-多样性联系，而围栏封育则优先考虑土壤养分-植物多样性相关性。至关重要的是，放牧通过改变土壤微环境，逆转了土壤pH值的功能作用，从围栏封育区对微生物群落的正向调节变为负面影响。这些结果提供了一个管理实践重组生态网络的框架。围栏封育加强了土壤养分介导的植物-土壤反馈，而放牧促进了pH值驱动的微生物选择和生物量分配策略的变化。同时，围栏封育效果的空间变异性突出了当地环境背景对草地管理后果的重要性。
