Soil physicochemical characteristics of different vegetation types along Qinghai-Tibet Engineering Corridor
Dong Linshui, Song Aiyun, Zhou Jinxing, Jiang Xingui
1. Key Laboratory of Eco-environmental Science for Yellow River Delta, handong Province, Binzhou University, 256603, Binzhou,Shandong,China;
2. School of Soil and Water Conservation,Beijing forestry University,Key Laboratory of Soil and Water Conservation & Desertification Combating,Ministry of Education,100083, Beijing,China;
3. Institute of Desertification Studies, Chinese Academy of Forestry, 100091, Beijing, China
[Background] It is necessary to analyze the soil physicochemical characteristics along the Qinghai-Tibet Engineering Corridor ( QTEC ) for formulating scientific and reasonable vegetation restoration measures. [Methods] Soil physicochemical characteristics of different vegetation types along QTEC were surveyed. Altogether 27 transects were set up, 8 plots of 20 m 伊20 m were selected in each transect, randomly sampling 5 times in the soil layer of 0 -20 cm and 20 -40 cm of each plot, then 5 samples were mixed into 1 soil sample. The soil sample in each transect was tested, the detection indexes of soil samples including the contents of soil organic matter, total nitrogen, total phosphorus, total potassium, pH value, cation exchange capacity, and calcium carbonate content were analyzed. Also the vegetation types, community structure of each transect were nvestigated. [Results] The results showed that the contents of soil organic matter and total nitrogen increased gradually from north to south along QTEC, and were closely correlated to vegetation types. The content of soil organic matter changed in the range of 10.0 -40.0 g/ kg. And the content of total nitrogen distributed within the scope of 0.4 -2.0 g/ kg. The contents of soil organic matter and total nitrogen presented a significantly linear correlation with each other. The content of soil total phosphorus mostly was in the range of 0.3 -0.8 g/ kg. From north to south, there was significant uptrend of the soil total potassium content along QTEC,the total potassium of the transects in south of Nagqu mostly was among 22.0 - 30.0 g/ kg, however, the value in the north transects of Nagqu was in the range of 13.0 - 22.0 g/ kg. The soil pH value of the transects in the northern part of QTEC were mostly higher than the transects in the southern part. The soil cation exchange capacity of the transects along QTEC was in the range of 6.0 - 24.0 cmol ( + ) / kg. The content of soil calcium carbonate mostly was among 8.0% -15.0%, but the southern part from Gaqia to Lhasa mostly was only in the range of 1.0% -3.0%, this obvious distinction was mainly concerned with the soil calcium deposition. [Conclusions] In summary, there were very regular dynamic change discipline of soil chemical characteristics along the QTEC. The result showed that some soil indexes were closely correlated to vegetation types, such as organic matter, total nitrogen, et al, while other indexes had no obvious correlation with the vegetation types like exchange capacity of soil cation. In the future, the dynamic monitoring of soil physical and chemical characteristics should be further proceeded.