Grazing promotes decomposition of litter in alpine meadow through decoupling climate

Litter decomposition plays a critical process driving the cycling of carbon (C), nitrogen (N), and phosphorus (P). However, the combined effects of grazing system (GS) and grazing intensity (GI) on litter decomposition remain unclear. In this study, a two-year experiment was conducted to examine effects of two GS (CG – continuous grazing, and RG – rotational grazing) and two GI (0 and 8 sheep ha −1 ) on litter decomposition in an alpine meadow on the Qinghai-Tibetan Plateau (QTP). GI at 8 sheep ha −1 increased decomposition rate of litter dry matter (DM) by 78.2 %, C by 8.9 %, N by 110.3 %, and P by 25.6 % compared to no grazing. RG enhanced decomposition rate of DM by 24.9 %, C by 27.0 %, N by 52.4 %, and P by 3.8 % compared to CG. GI exerted a stronger effect on litter decomposition than GS and their interaction (GS × GI). The litter turnover rate was the fastest at GI at 8 sheep ha −1 . RG reduced annual litter decomposition mass per unit area of pasture by 42.7 %, while CG reduced it by 19.6 %. Stoichiometric characteristics of litter contributed 19.0 %, −4.3 %, 22.3 %, and 4.2 % to litter DM, C, N, and P decomposition, respectively. Initial C content, solar radiation, litter allocation coefficient, and solar radiation explained 10.1 %, 12.5 %, 12.0 %, and 10.5 % variance in DM, C, N, and P decomposition, respectively. Grazing decoupled climate effects, thereby promoting litter decomposition. The results suggest that grazing enhances decomposition and turnover of litter in the QTP, providing insights into nutrient cycling under global climate change.