Divergent Effects of Grazing Intensity on Soil Nutrient Fractions in Alpine Meadows

作者：Tserang Donko Mipam, Ao Jiang, Luhuai Jing, Sihu Zhang, Yi Wei, Chen Zhao, Yi Ai, Liming Tian · 发表于：Land Degradation and Development · 年份：2024 · DOI：10.1002/ldr.5289 · 被引用次数：9 · 研究领域：Soil Carbon and Nitrogen Dynamics、Rangeland Management and Livestock Ecology、Peatlands and Wetlands Ecology

ABSTRACT Large herbivore grazing plays a key role in regulating ecosystem functioning and nutrient cycling in terrestrial ecosystems. However, the effects and mechanisms of large herbivore grazing intensity on soil nutrient fractions remain largely unclear in alpine grasslands. Here, we determine 20 indicator variables associated with soil nutrient fractions (e.g., particulate organic carbon, POC; mineral‐associated organic carbon, MAOC) to investigate how grazing intensity on labile fractions through a well‐controlled grazing experiment in an alpine meadow on the eastern Tibetan Plateau. Our results show that microbial biomass carbon, dissolved organic carbon, light fraction organic carbon, microbial biomass nitrogen and phosphorus, total potassium, and available potassium significantly decrease with increased grazing intensity, whereas other fractions (e.g., POC, MAOC, dissolved organic nitrogen, ammonium nitrogen, nitrate nitrogen, available nitrogen, etc.) have marginal or non‐significant responses to grazing intensity. Further analysis reveals that above‐and below‐ground biomass, soil moisture, and soil pH jointly determine the grazing effects on soil nutrient fractions, without the impact of species richness. Moreover, correlation analyses indicate that grazing intensity decouples carbon and nitrogen from phosphorus and potassium in alpine meadows. Collectively, our results emphasize the importance of grazing intensity effects on nutrient cycling in alpine grasslands an...