HUANG Yimin1,2, LEE Xinqing1*, YANG Fang1,2, HUANG Daikuang3, XING Ying4
(1. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China;
2.University of Chinese Academy of Sciences, Beijing 100049, China;
3. Guizhou Academy of Environmental Science and Designing, Guiyang, 550000, China;
4. Guizhou Normal University, Guiyang, 550000, China; )
Abstract: knowledge of the soil carbon storage and its affecting factors to Karst area is indispensable for understanding the capacity of carbon sequestration by terrestrial ecosystems of China. Based on analysis of soil organic carbon in a continuous transect from the northern slope of the Qinling Moutains, the Central China, to the border of China to Vietnam, we studied spatial variation and its controlling factors of soil organic carbon to the top 10 cm of soil profile in Karst forests of the Southwestern China. We found that soil organic carbon content (SOC) and soil organic carbon density (SOCD) averaged 32.3g/kg and 33.1 t/hm2, respectively. These values are both lower than that of the forest soil of non-Karst forests in either the Southwestern China or its provinces. Path analysis indicates that soil bulk density, topographic elevation and C/N of soil organic matter are major factors to the variations of SOC and SOCD while clay content and annual temperature exert little impact, and annual precipitation only affects SOCD of Shaanxi Province in the most northern part of the studying region, where semi-arid climate dominates. The trivial effect of climate to the soil organic carbon inventory contrasts sharply with many parts of the world, especially at high latitudes, suggesting that major factors to soil organic carbon may differ from region to region or climate to climate. The results are important for understanding the feedback of soil organic carbon stock to the current global warming.
Key words: soil carbon pool; climate change; carbon storage; karst; carbonate; rocky desertification
EARTH AND ENVIRONMENT Vol. 44, No.1 Tot No.309, 2016, Page 1-10
