Alpine Grassland Aboveground Biomass and Theoretical Livestock Carrying Capacity on the Tibetan Plateau

作者：Zhang Xianzhou, Meng Li, Jianshuang Wu, Yongtao He, Niu Ben · 发表于：Journal of Resources and Ecology · 年份：2022 · DOI：10.5814/j.issn.1674-764x.2022.01.015 · 被引用次数：25 · 研究领域：Rangeland Management and Livestock Ecology、Ruminant Nutrition and Digestive Physiology、Soil erosion and sediment transport

The accurate simulation and prediction of grassland aboveground biomass (AGB) and theoretical livestock carrying capacity are key steps for maintaining ecosystem balance and sustainable grassland management. The AGB in fenced grassland is not affected by grazing and its variability is only driven by climate change, which can be regarded as the grassland potential AGB (AGBp). In this study, we compiled the data for 345 AGB field observations in fenced grasslands and their corresponding climate data, soil data, and topographical data on the Qinghai-Tibetan Plateau (TP). We further simulated and predicted grassland AGBp and theoretical livestock carrying capacity under the climate conditions of the past (2000–2018) and future two decades (2021–2040) based on a random forest (RF) algorithm. The results showed that simulated AGBp matched well with observed values in the field (R 2 = 0.76, P < 0.001) in the past two decades. The average grassland AGBp on the Tibetan Plateau was 102.4 g m–2, and the inter-annual changes in AGBp during this period showed a non-significant increasing trend. AGBp fluctuation was positively correlated with growing season precipitation (R 2 = 0.57, P < 0.001), and negatively correlated with the growing season diurnal temperature range (R 2 = 0.51, P < 0.001). The average theoretical livestock carrying capacity was 0.94 standardized sheep units (SSU) ha–1 on the TP, in which about 54.1% of the areas showed an increasing trend during the past two decades. ...