【摘要】 采用对比研究的方法,研究了汶川地震后龙门山东、西坡及过渡区域典型山地滑坡体土壤理化性质以及土壤养分含量的变化.结果显示:与未破坏的原生土壤相比较,3个区域滑坡迹地土壤砂粒含量均显著升高;土壤阳离子交换量、有机质、全氮、全磷、硝态氮、总矿质氮、土壤粉粒和粘粒含量显著降低;滑坡体土壤pH值在东坡和过渡区显著升高,西坡升高不明显;东坡和过渡区滑坡体土壤氨态氮含量与矿质氮/全氮比值显著降低,而西坡差异不显著;土壤碳/氮比值在过渡区显著下降,东坡和西坡差异不显著.此外,3个研究区域滑坡体土壤全钾含量变化不显著.滑坡迹地表征土壤质量的指标(土壤质地、有机质和矿质元素含量等)总体上呈现下降的趋势,表明地震对滑坡体土壤产生了明显的破坏作用;土壤的碳损失率大于氮损失率,并有可能会进一步加剧土壤的碳缺失.地震对龙门山区域土壤理化性质的影响仅有氨态氮存在扰动与空间区域的交互作用,其余理化指标的扰动结果均不受空间区域差异均的影响.这暗示地震有可能是通过对土壤剖面层次的破坏和扰动而影响土壤理化性质,生态气候类型差异对于滑坡迹地土壤理化性质的改变效应可能是一个比较长期的过程.更多还原

【Abstract】 The Ms 8.0 Wenchuan earthquake in 2008 led to huge damage to land covers in northwestern Sichuan,one of the critical fragile eco-regions in China.In this paper,the soil physical and chemical properties at the landslide sites induced by the earthquake were assessed in a comparable framework which included three regions,i.e.eastern side,western side and the transitional zone of the Longmen Mountain,and represented different climate and vegetation background.Compared with the undisturbed area,the results indicated that soil sand content increased significantly on the landslide of all case-study areas(P<0.05),while cation exchange capacity,organic matter,total nitrogen,total phosphorus,nitrate nitrogen,mineral nitrogen,silt content and clay contents decreased significantly(P<0.05) in all three research regions.The soil pH,the ammonia nitrogen content,and the ratios of mineral nitrogen/total nitrogen and C/N did not show a regular trend.Moreover,the total potassium content did not change obviously(P>0.05) in the three regions.In conclusion,most of the soil quality indices decreased significantly on earthquake-triggered landslides.更多还原