Dynamics of soil organic carbon in Caragana microphylla forest and its relationship with environment factors in loess hilly region
QU Wei-Dong, CHEN Yun-Meng, WANG Lin-Lin, ZHANG Fei, ZHANG Hua-Wu
1.College of Resources and Environment, Northwest A&F University, 712100,Yangling, Shaanxi; 2.Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 712100, Yangling, Shaanxi; 3.Yulin Green Superman Water Conservancy Design Co., Ltd,719000,Yulin, Shaanxi; 4.East China Investigation and Design Institute Under CHECC, 310014, Hangzhou: China
Abstract：The variation rule of soil organic carbon density in the growing process of man-made forest was studied by taking Caragana microphylla plantation in loess hilly region as the research object with field survey and laboratory analysis. The results indicated as follows: 1) Soil organic carbon are mainly distributed in the 0-20cm soil layer，which accounted for 49% to 63% of total soil organic carbon content in 0-50cm soil layer. 2) Compared with the control, the soil organic carbon density of C. microphylla plantations decreased firstly, then increased，and stabilized finally over growing process. Total soil organic carbon density of C. microphylla plantation in age 10a，26a，40a，50a were respectively 1.555, 3.236, 2.775, 2.444kg/m2. The highest value was in 26a-woodland. It tent to stable over forest age. 3) Correlation analysis showed that there was a significant negative correlation between soil organic carbon content and soil bulk density, soil bulk density decreased over forest age. So it can be concluded that C. microphylla could improve soil organic carbon content indirectly by affecting soil characteristics. The soil organic carbon content had significant positive relation with root biomass and the content of total nitrogen, which proved that the root growth and nitrogen fixation characteristics of C. microphylla contributed to soil organic carbon accumulation.
2011, Vol. 9 
