摘要
侵蚀和再沉积过程可导致土壤碳库在空间上重新分布,但至今对这一过程中不同碳库的迁移和再分布特点还了解不多。在浙江省亚热带地区选择了由严重侵蚀区—轻微侵蚀区—坡脚堆积区—坡底堆积区组成的侵蚀—沉积系列连续地形,分别采集了4个代表性土壤剖面,研究了不同地形部位土壤碳库的分异特征,探讨了侵蚀—再沉积过程中各种碳库的转归。结果表明,土壤有机总碳及各组分碳均是:严重侵蚀区<轻微侵蚀区<坡脚堆积区<坡底堆积区。侵蚀区土壤总有机碳自上而下明显下降,而堆积区土壤有机碳库分布较深,垂直变化相对平缓。黑碳极易随地表径流发生迁移,呈由高处逐渐向低处明显富集的趋势。堆积区为连续地形中的碳汇。
Soil erosion and re-deposition may result in redistribution of soil carbon in terrestrial systems. However, limited information is available about transfer and redistribution characteristics of various soil organic C in the processes of the erosion and re-deposition. A representative erosion-deposition landform, consisting of strongly eroded zone, slightly eroded zone, slope depositional zone, and bottom depositional zone, was selected to sample four soil profiles for studying the spatial variation of various organic carbon pools in different landform positions and exploring fate of various organic C in the processes of soil erosion-deposition. Results showed that intrinsic characteristics of various organic C greatly affected their transfer and distribution behaviors. Contents of total soil organic C and its components increased in the ascendant order of strongly eroded zone, slightly eroded zone, slope depositional zone, and bottom depositional zone. Total organic C content of soil profiles in the eroded zones decreased significantly along with sampling depth, meanwhile those in depositional areas kept relatively high organic C in all sampling depths, even at the deep layer. Black C is the most mobile form of soil organic C and it tended to be accumulated in the soils in bottom depositional zone of the continuation landform. Because of being buried or physically protected from decomposition in the depositional zones, organic C in the zones was C sink.
出处
《水土保持通报》
CSCD
北大核心
2009年第3期61-65,共5页
Bulletin of Soil and Water Conservation
基金
国家自然科学基金(4077109040471064)
关键词
侵蚀-沉积连续地形
颗粒态有机碳
黑碳
迁移
空间分异
erosion-deposition continuation landform
particulate organic C
black C. transfer： spatial variation
