Responses and mechanisms of soil greenhouse gas fluxes to changes in precipitation intensity and duration: a meta-analysis for a global perspective

Abstract

Although extensive manipulative experiments have been conducted to study the effects of altered precipitation intensity and duration on soil greenhouse gas (GHG; carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)) fluxes, the general patterns of GHGs to altered precipitation have not been globally described across biomes. Thus, we performed a meta-analysis of 84 published studies to examine the general responses of CO2, CH4, and N2O fluxes to altered precipitation. Our results indicated that increased precipitation significantly increased N2O emissions (+154.0%) and CO2fluxes (+112.2%) and significantly decreased CH4uptake (−41.4%); decreased precipitation significantly decreased N2O emissions (−64.7%) and CO2fluxes (−8.6%) and significantly increased CH4uptake (+32.4%). Moreover, increased precipitation significantly increased litter biomass and microbial biomass and decreased root biomass and the root:shoot ratio. However, decreased precipitation significantly decreased litter biomass and root biomass and significantly increased root:shoot ratio. These results suggest that precipitation changes could alter the carbon distribution patterns in plants. In addition, the CO2, CH4, and N2O fluxes exhibited diverse responses to different ecosystems, durations of precipitation changes, and changes in precipitation intensity. These results demonstrate that there are many factors that regulate the responses of GHG to precipitation changes.