Soil respiration under climate warming: differential response of heterotrophic and autotrophic respiration

• Published in: Global Change Biology
• Main Authors: Wang, Xin, Liu, Lingli, Piao, Shilong, Janssens, Ivan A., Tang, Jianwu, Liu, Weixing, Chi, Yonggang, Wang, Jing, Xu, Shan
• Format: Article in Journal/Newspaper
• Language: English
• Published: WILEY 2014
• Subjects: acclimation; apparent Q10; ecosystem warming; forest; grassland; mediterranean; meta-analysis; soil moisture; tundra; warming duration; Biodiversity Conservation; Ecology; Environmental Sciences; ECOSYSTEM CARBON FLUXES; CO2 EFFLUX; TEMPERATURE SENSITIVITY; MICROBIAL RESPIRATION; THERMAL ADAPTATION; ELEVATED CO2; CYCLE; COMPONENTS; WATER; Biodiversity & Conservation; Environmental Sciences & Ecology; Tundra
• Online Access: http://ir.ibcas.ac.cn/handle/2S10CLM1/27172; https://doi.org/10.1111/gcb.12620

Despite decades of research, how climate warming alters the global flux of soil respiration is still poorly characterized. Here, we use meta-analysis to synthesize 202 soil respiration datasets from 50 ecosystem warming experiments across multiple terrestrial ecosystems. We found that, on average, warming by 2 degrees C increased soil respiration by 12% during the early warming years, but warming-induced drought partially offset this effect. More significantly, the two components of soil respiration, heterotrophic respiration and autotrophic respiration showed distinct responses. The warming effect on autotrophic respiration was not statistically detectable during the early warming years, but nonetheless decreased with treatment duration. In contrast, warming by 2 degrees C increased heterotrophic respiration by an average of 21%, and this stimulation remained stable over the warming duration. This result challenged the assumption that microbial activity would acclimate to the rising temperature. Together, our findings demonstrate that distinguishing heterotrophic respiration and autotrophic respiration would allow us better understand and predict the long-term response of soil respiration to warming. The dependence of soil respiration on soil moisture condition also underscores the importance of incorporating warming-induced soil hydrological changes when modeling soil respiration under climate change.