Soil respiration under climate warming: differential response of heterotrophic and autotrophic respiration.
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 °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 °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.
State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, 100093, China; University of Chinese Academy of Sciences, Yuquanlu, Beijing, 100049, China.
Xin
X
Wang
Lingli
L
Liu
Shilong
S
Piao
Ivan A
IA
Janssens
Jianwu
J
Tang
Weixing
W
Liu
Yonggang
Y
Chi
Jing
J
Wang
Shan
S
Xu
D000064:Acclimatization; D052818:Autotrophic Processes; D057486:Carbon Cycle / Q000502:physiology*; D057231:Climate Change; D055864:Droughts; D017753:Ecosystem; D052836:Heterotrophic Processes; D006358:Hot Temperature; D012988:Soil Microbiology
acclimation; apparent Q10; ecosystem warming; forest; grassland; mediterranean; meta-analysis; soil moisture; tundra; warming duration