The Responses of Soil Respiration and Nitrogen Mineralization to Global Warming in Terrestrial Ecosystems
陆地生态系统土壤呼吸、氮矿化对气候变暖的响应

Study on the responses of soil respiration and nitrogen mineralization to global warming is very important to understand the balance of the terrestrial carbon budget. Soil respiration will increase as temperature increase in short-term. However, it would have no sensitivity to wanning or acclimation in long-term. The temperature sensitivity of soil respiration is heterogeneous temporally and spatially since it is controlled by environmental factors such as soil water content, climate, vegetation, litters and so on. Therefore, many uncertainties will be unavoidable when a fixed Q10 is used to calculate the variations of soil respiration. The responses of terrestrial ecosystems to warming have complex acclimations besides direct reactions. Although the results of modeling suggest that soil respiration would increase due to global warming, big uncertainties still exists in modeling soil respiration due to lacking of measurements about acclimation of soil respiration to warming. Soil nitrogen mineralization rates are promoted by the global wanning. The extents of effects are related to not only temperature, but also soil substrate quality and quantity, soil water, the duration time of increasing temperature and so on. Due to the integrated effects of these factors, many uncertainties appear. The problems above will be solved by use of uniform methods, distinguishing of the responses of different components of soil respiration to wanning, and consideration of other factors such as both increases and decreases in the quantity and distribution of region precipitation, increased N deposition and elevated atmospheric CO2 concentration.