| 黄土丘陵区不同有机碳背景下侵蚀坡面土壤呼吸特征 |
| 摘要点击 2011 全文点击 996 投稿时间：2015-02-04 修订日期：2015-04-06 |
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| 中文关键词 土壤呼吸 侵蚀 坡面 有机碳 土壤温湿度 |
| 英文关键词 soil respiration erosion slope position SOC soil temperature and moisture |
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| 中文摘要 |
| 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6.82g ·kg-1时,坡面侵蚀趋向于碳汇过程; 当有机碳含量小于3.03g ·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. |
| 英文摘要 |
| 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 6.82g ·kg-1, the slope erosion tended to be a carbon sequestration process, and when SOC content was lower than 3.03g ·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. |
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