作者
Weikang Zhao,Yan Zhang,Yi Sun,Fujiang Hou
摘要
ABSTRACT Dung decomposition plays a pivotal role in the cycling of carbon (C), nitrogen (N), and phosphorus (P). However, the combined effects of grazing system and grazing intensity on dung decomposition remain unclear. In this study, a 2‐year experiment was conducted to examine the effects of two grazing systems (continuous grazing and rotational grazing) and two grazing intensities (0 and 8 sheep ha −1 ) on Tibetan sheep dung decomposition in an alpine meadow on the Qinghai‐Tibetan Plateau. Grazing intensity at 8 sheep ha −1 enhanced the decomposition rate of dung dry matter (DM) by 8.6%, C by 25.8%, N by 16.7%, and P by 63.4% compared to no grazing. Rotational grazing enhanced the decomposition rate of DM (3.7%), C (6.6%), N (57.9%), and P (101.2%) compared to continuous grazing. Grazing intensity exerted a stronger effect on dung decomposition than grazing system and their interaction (grazing system × grazing intensity). The fastest dung turnover rate occurred at a grazing intensity of 8 sheep ha −1 . Rotational grazing increased the annual dung decomposition mass per unit area of pasture by 55.1% compared to continuous grazing. The stoichiometric characteristics of dung contributed −71.9%, −22.4%, 66.0%, and 8.7% to dung DM, C, N, and P decomposition, respectively. Day and night temperature difference, and initial C, N, and P contents explained 14.8%, 10.6%, 14.8%, and 10.6% variance in DM, C, N, and P decomposition, respectively. Grazing decoupled climate effects, thereby promoting dung decomposition. The results suggest that grazing promotes the decomposition and turnover of Tibetan sheep dung in the Qinghai‐Tibetan Plateau, providing insights into nutrient cycling under global climate change.