Forest Soil Carbon Efflux Evaluation Across China: A New Estimate With Machine Learning
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- Chinese Academy of Sciences (CAS), Beijing (China); National Forestry and Grassland Administration, Beijing (China); University of Chinese Academy of Sciences, Beijing (China)
- Pacific Northwest National Laboratory (PNNL), Richland, WA (United States). Joint Global Change Research Institute; University of Maryland, College Park, MD (United States)
- Chinese Academy of Sciences (CAS), Beijing (China)
- Lanzhou University (China)
Forest soil respiration (Rs) plays an important role in the carbon balance of terrestrial ecosystems. China's forest occupies a large part of the world's forest. However, due to the lack of integrated observation data and appropriate upscaling methodologies, substantial uncertainties exist in the Rs evaluation, which limits our understanding of the carbon balance. Here, we re-evaluated the total soil carbon effluxes across China by combining field observations from 634 published annual Rs with a machine learning technique (i.e., Random Forest (RF)). Our results revealed that the combination of systematic measurements with the RF model allowed a definite estimate. The average annual Rs was 773.6 g C m-2 yr-1, ranging from 404.6 to 1,772.3 g C m-2 yr-1. Total forest soil carbon effluxes amounted to 1.17 Pg C yr-1 in China. Geographically, annual Rs showed a clear spatially increasing trend from northeast to southwest. Forest type is an important factor in determining the soil respiration rate. Bamboo and Evergreen broadleaf forests were higher than other types of forests. In conclusion, these results provide a unique insight into the magnitudes and mechanisms of soil CO2 emissions in China's forest ecosystems.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE; National Natural Science Foundation of China (NSFC)
- Grant/Contract Number:
- AC05-76RL01830; 32071592
- OSTI ID:
- 2229525
- Report Number(s):
- PNNL-SA-162066
- Journal Information:
- Global Biogeochemical Cycles, Vol. 37, Issue 8; ISSN 0886-6236
- Publisher:
- American Geophysical Union (AGU)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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