Role of ambient climate in the response of soil respiration to different grassland management measures

Assessment of the effects of enclosure and grazing on soil respiration based on long-term continuous field observations is scarce, and seasonal dynamics of the dependence of soil respiration on hydrothermal factors (soil moisture and temperature) and the regulation of soil respiration by ambient climate (precipitation and air temperature) under long-term fencing and grazing have been inconclusive so far. A 14-year continuous field observation experiment was conducted in a temperate grassland in China. Our results showed that grazing decreased the average soil respiration over the whole year and growing season by 19.52% and 21.90%, respectively. Furthermore, grazing increased the dependence of soil respiration on soil moisture on an annual timescale but decreased the dependence of soil respiration on temperature during the growing season. Ambient climate determined the direction of interannual variation of soil respiration, while grassland management measures changed the effect size of ambient climate on soil respiration. This highlights that ambient climate plays a decisive role in regulating the response of soil respiration to change in grassland management measures.