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耕作与水蚀是黑土区坡耕地碳库退化的主导因素,为进一步探究土壤有机碳(SOC)及其组分对不同侵蚀驱动力(耕作、水力)的响应格局,基于该区耕作侵蚀与水蚀模型,在定量表达耕作侵蚀-沉积量与水蚀量的基础上,利用地统计学的方法,分析了东北黑土区典型漫岗地形坡面尺度SOC及其3种组分的空间分布特征.结果表明:耕作侵蚀与沉积速率分别表现为坡上>坡下>坡中>坡脚和坡脚>坡下>坡中>坡上;水蚀速率表现为坡下>坡脚>坡中>坡上;坡下陡坡位置耕作侵蚀与水蚀协同引起严重的土壤流失.虽然耕作侵蚀速率(0.02~7.02t·hm~(-2)·a~(-1))远小于水蚀速率(5.96~101.17 t·hm~(-2)·a~(-1)),但耕作侵蚀在全坡面范围均可对SOC产生不同程度的影响,而水蚀则主要在坡下径流汇集区显著影响SOC的累积-损耗.受水蚀与耕作侵蚀-沉积作用影响,SOC、颗粒有机碳、水溶性有机碳在侵蚀点含量低于沉积点,而微生物生物量碳变化趋势相反;耕作侵蚀通过影响颗粒有机碳参与SOC的积累-损耗过程.
Tillage and water erosion are the dominant factors of carbon pool degradation on arable land in black soil region. In order to further investigate the response of soil organic carbon (SOC) and its components to different erosion drivers (tillage and hydraulic) Based on the quantitative analysis of soil erosion-sediment amount and water erosion amount, the spatial-scale characteristics of slope-scale SOC and its three components of the typical upwelling terrain in the black soil region of northeastern China were analyzed by geostatistics method. The results showed that: The erosion and sedimentation rates of tillage showed the slope> slope> slope> slope foot and slope foot> slope> slope> slope respectively. The water erosion rate showed slope> slope> slope> slope; Severe soil loss caused by tillage erosion and water erosion at the steep slope resulted in severe soil erosion, although the tillage erosion rate (0.02-7.02 t · hm -2 · a -1) was much lower than the water erosion rate (5.96-101.17 t · hm -1) -2) · a ~ (-1)), but tillage erosion can affect the SOC to some extent in all slopes, while water erosion mainly affects the accumulation-loss of SOC mainly in the runoff gathering area of the slope. In contrast with tillage erosion-sedimentation, the content of SOC, particulate organic carbon and water-soluble organic carbon at erosion point was lower than that of sediment Point, but rather change of microbial biomass carbon; Effect of tillage erosion by particulate organic carbon accumulation involved in SOC - Depletion.