Driving factors analysis of soil respiration in China ecosystems

Soil respiration (Rs) is the second largest carbon flux in terrestrial ecosystems after photosynthesis, and it is deeply affected by climatic, geographical, and plant factors. This study aims to quantify and clarify the response of Rs to driving factors in natural vegetation formed by natural succession under different conditions.

Through meta-analysis, we quantified the individual and interactive effects of nitrogen addition (NA), precipitation increase/decrease (PI/PD), warming (W), and aboveground biomass removal (AGBR) on natural vegetation Rs in China.

NA had no significant effect on Rs of natural vegetation, PI and W increased Rs by 17.4% and 9.8%, while PD and AGBR significantly decreased Rs by 18.5% and 11.8%, respectively, and the interactive effect of NA, PI, and W showed additive effects on Rs. Precipitation was key in influencing the response of Rs to driving factors, which had significant changes along the precipitation gradient. Specifically, the driving factors decreased Rs by 9.9–27.4% in arid regions (Except for PI), which was limited by the water effectiveness, so forests mainly formed by natural succession in humid areas, had a stronger moderating effect than grassland under driving factors.

Precipitation is a key factor influencing the effect of drivers on soil respiration, and natural forest ecosystems formed in humid areas have a stronger regulatory role, compared to natural grasslands limited by water and nitrogen. This study analyzed the influencing mechanisms of driving factors on Rs in natural ecosystems, which is crucial for assessing carbon cycle processes under climate change.