Difference analysis of soil organic carbon pool in different forestlands returned from farmlands in karst gorge area
Tang Fukai, Cui Ming, Zhou Jinxing, Yan Shuai, Ding Fangjun, Lü Xianghai
1. Research Institute of Desertification, Chinese Academy of Forestry ,100091, Beijing,China; 2. Guizhou Academy of Forestry,550005, Guiyang,China; 3. China International Engineering Consulting Corporation, 100048, Beijing, China
To determine the effects of different forestlands returned from farmlands on soil organic carbon and carbon pool management level in karst areas, soil organic carbon (SOC) contents, density and carbon management index ( ICM ) under six different land-use types, including conventional farmland (CT), abandoned farmland ( AF), farmland returned to plantations of Dodonaea viscosa ( DV), Zanthoxylum scandens (ZA), Toona sinensis (TS) and Vernicia fordii (VF), were studied in Huajiang gorge area of Guizhou Province. The results showed that: 1) compared with farmland, total organic carbon (TOC) content and density of lands converted from farmlands increased significantly (P<0.05). TOC in 0 -20 cm layer ranged from 13.00 -34.07 g/kg, with farmland the lowest while Toona sinensis the highest. TOC density in soil profile presented a trend of TS> VF>AF>DV>ZA >CT. 2)Both TOC content and TOC density decreased with the increase of soil depth in all land-use types. TOC contents in 0 -20 cm soil were 1.11 -1.37 times as high as the cross-sectional mean value, while SOC density in 0 -20 cm deep soil accounted for 35.68% -46.45% of the entire section, showing an obvious table cohesion. 3) Taking farmland as a reference, ICM of all the other four converted lands were obviously greater than 1 except for Z. scandens. Vegetation recovery can effectively improve soil carbon pool management level, with T. sinensis and V. fordii having the highest efficiency. In addition, the change of LOC/ TOC ratio had the same tendency as the variation of TOC content. RL/ T can be used as an important indicator to reflect the level of carbon management. In summary, returning farmland to forests has the potential of expanding capacity of carbon pool and improving soil quality; therefore, we should pay attention to selecting suitable restoration modes, increasing vegetation cover as well as reducing human disturbance.
唐夫凯1,崔明1,周金星1,闫帅1,丁访军2,吕相海3. 岩溶峡谷区不同退耕还林地土壤有机碳库差异分析[J]. 中国水土保持科学, 2014, 12(4): 1-7.
Tang Fukai, Cui Ming, Zhou Jinxing, Yan Shuai, Ding Fangjun, Lü Xianghai. Difference analysis of soil organic carbon pool in different forestlands returned from farmlands in karst gorge area. SSWCC, 2014, 12(4): 1-7.