I focus on the responses of ecosystem carbon source/sink to climate warming in Tibetan permafrost and rotation management practices in karst agroecosystem. I am interested in 1) whether climate warming will change the permafrost C budget when considering the cold season efflux and equivalent-CO₂ of CH₄ and N₂O, particularly considering warming-induced changes in freeze-thaw cycling, soil hydrothermal of active layer, growing season NEE, and the related microbiome of greenhouse gases; 2) accessing the greenhouse gas intensity (GHGI), net ecosystem carbon budget (NECB), net ecosystem economic benefits (NEEB) and nutrients use efficiency under long term green manure-corn/paddy rotation and combination of organic fertilizer application and chemical fertilizer reduction managements.