Moderate grazing increased carbon, nitrogen and phosphorus storage in plants and soil in the Eurasian meadow steppe ecosystem

• Published in: The Science of the total environment Vol. 914; p. 169864
• Main Authors: Wang, Miao, Zhang, Chu, Chen, Sisi, Zhang, Yu, Yu, Tianqi, Xue, Xiaojuan, Wu, Lianhai, Zhou, Wenneng, Yun, Xiangjun, Yan, Ruirui, Bai, Keyu
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2024
• Subjects: Ecosystem nutrient cycling; Grazing intensity; Meadow grassland; Nutrient storage; Meadow grassland; Nutrient storage; Ecosystem nutrient cycling; Grazing intensity
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.169864

The effects of grazing on the cycling of carbon (C), nitrogen (N) and phosphorus (P) in grassland ecosystems are complex. Uncertainty still exists as regards the allocation of C, N and P storage amounts in grazed ecosystems in Inner Mongolia, situated at the eastern end of the Eurasian dryland. Based on the long-term cattle grazing experimental platform in the Hulun Buir meadow steppe of Inner Mongolia, a 3-year (2019–2021) field control experiment was conducted to assess how the grazing intensity influenced the quantities of C, N and P stored in canopy biomass, root, litter and soil compartments. We examined the relationships between the different pools and their regulatory pathways at the ecosystem level across six grazing intensities. In general, grazing increased the aboveground N and P contents but decreased the aboveground biomass C content and nutrient storage amounts in aboveground biomass, roots and litter. The grazing intensity of 0.34 AU ha−1 increased soil organic carbon, total nitrogen and total phosphorus storage amounts, with the soil accounting for 98 % of total reserves on average. Grazing affected soil pH， nutrient contents, above- and belowground biomass and soil environmental factors such as soil bulk density, which in turn affected C, N and P storage in the ecosystem according to the results of the structural equation model; therefore, grazing intensity can be an important factor regulating the input and output of nutrients in the ecosystem. In the future, for adaptive management of grasslands, moderate grazing could effectively increase C, N and P storage in meadow steppe ecosystems and ensure the nutrient balance and long-term sustainable development. [Display omitted] •Grazing reduced element storage in aboveground, roots and litter.•The proportion of soil element storage to total ecosystem storage increased with the increase of grazing intensity.•Grazing intensity affects ecosystem element storages by affecting soil environmental factors, biomass and nutrient content.•Moderate grazing intensity is beneficial to increase the element storages of meadow steppe ecosystem.