水保所知识产出(1956---)知识库

以黄土丘陵区5 个不同有机碳背景的坡面S 型小区( 坡顶为对照区、坡中为侵蚀区、坡脚为沉积区) 为研究对象，通过
对土壤呼吸速率的动态观测，分析坡面不同类型区土壤呼吸特征及其与土壤温湿度、有机碳和坡位的关系． 结果表明，土壤
温度的变化对沉积区土壤呼吸影响较大，土壤湿度的变化对侵蚀区土壤呼吸影响较大． 有机碳是影响土壤呼吸的首要因子，
可解释土壤呼吸变异的54. 72%; 其次是土壤湿度、坡位和土壤温度，分别可解释土壤呼吸变异的18. 86%、16. 13% 和
10. 29%． 侵蚀对坡面土壤呼吸的影响具有明显的原位和异位效应，侵蚀导致坡面侵蚀区土壤呼吸减小了21. 14%，沉积区土
壤呼吸增大了21. 93%． 侵蚀坡面土壤碳排放的源汇效应与有机碳水平有关，当土壤有机碳含量大于6. 82 g·kg － 1 时，坡面侵
蚀趋向于碳汇过程; 当有机碳含量小于3. 03 g·kg － 1 时，坡面侵蚀趋向于碳源过程． 文中模型可以较好地反映有机碳和土壤温
湿度与土壤呼吸的关系．

This study aimed to characterize soil respiration along eroded sloping land at erosion and deposition area under different soil
organic carbon( SOC) levels，and linked the relationship between soil respiration and soil temperature，soil moisture，SOC and slope
position． Experiments were carried out in the plots of S type slopes include five different soil organic carbon levels in the Loess Hilly
Ｒegion． The S type slopes were divided into control area at the top of the slope，erosion area at the middle of the slope and deposition
area at the toe of the slope． We found that soil temperature had a greater impact on soil respiration in the deposition area，whereas soil
moisture had a greater impact on soil respiration in the erosion area compared among control area，erosion area and deposition area． In
addition，SOC was the most important factor affecting soil respiration，which can explain soil respiration variation 54. 72%，followed by
soil moisture， slope position and soil temperature，which explain soil respiration variation 18. 86%，16. 13% and 10. 29%，
respectively． Soil respiration response to erosion showed obvious on-site and off-site effects along the eroded sloping land． Soil
respiration in the erosion area was reduced by 21. 14% compared with control area，and soil respiration in the deposition area was
increased by 21. 93% compared with control area． Erosion effect on source and sink of carbon emission was correlated with SOC
content of the eroded sloping land． When SOC content was higher than 6. 82 g·kg － 1 ，the slope erosion tended to be a carbon
sequestration process，and when SOC content was lower than 3. 03 g·kg － 1 ，the slope erosion tended to be a process of the carbon
emission source． The model could reflect the relationship between soil respiration and independent variables of soil organic carbon
content，soil temperature and moisture．