Rotational grazing promotes grassland aboveground plant biomass and its temporal stability under changing weather conditions on the Qinghai‐Tibetan plateau
Yu Li, Shikui Dong, Qingzhu Gao, Yong Zhang, Shiliang Liu, Hasbagan Ganjurjav, Guozheng Hu, Xuexia Wang, Yulong Yan, Hongbao Wu, Xiaoxia Gao, Shuai Li, Jing Zhang
Abstract
Abstract The aboveground biomass (AGB) production of grazed grasslands is mediated by climate, soil nutrients, livestock and other factors. How the biotic and abiotic factors directly or indirectly regulate AGB remains unclear. To fill this gap, from 2014 to 2017, we conducted a rotational grazing experiment to examine the response of AGB to biotic and abiotic factors in Nagqu, a typical alpine meadow community on the Qinghai‐Tibetan Plateau. Six yaks were rotationally grazed among three plots from July to September, meanwhile, three plots were set up to exclude from livestock as control; climate, plant biomass, and soil nutrients were investigated during grazing experiment, and then structural equation modeling was used to analyze the regulation of environmental factors on AGB. The results showed that precipitation affected AGB via affecting soil nitrate nitrogen (NO 3 ‐N), compensatory growth rate, and belowground biomass indirectly; temperature can directly and negatively affected AGB. In contrast grazing exclosure, rotational grazing increased both AGB and its temporal stability in alpine meadow community significantly ( p < .05). The temporal stability of the AGB was positively related to the asynchrony between high‐ and low‐palatability herbages ( p < .05). In conclusion, rotational grazing should be recommendable for alpine meadow management due to its benefits for community productivity and stability while current stocking rate should be reduced to a reasonable level, especially in a warm and drought year, to sustain plant compensatory growth under grazing.