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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.
A comparative study was conducted to study the changes of soil physical and chemical properties and soil nutrient contents of typical mountain landslides in the east, west and transition regions of the Longmen Mountains after the Wenchuan earthquake.The results showed that compared with the non-destructive native soils, the three landslides Soil sand content significantly increased; soil cation exchange capacity, soil organic matter, total nitrogen, total phosphorus, nitrate nitrogen, total mineral nitrogen, soil silt and clay content decreased significantly; soil pH in the landslide body in the eastern slope and the transition zone The ratio of soil ammonia nitrogen to mineral N / total N was significantly decreased in the landslide of the east slope and the transition zone, but not significant in the west slope; the soil C / N ratio decreased significantly in the transition zone , And there was no significant difference between the east slope and the west slope.In addition, the total potassium content of the landslide body did not change significantly in the three studied areas.The indexes of soil quality (soil texture, organic matter and mineral element content) characterizing the landslide generally showed a downward trend , Indicating that the earthquake had a significant damage to the soil in the landslide; the soil carbon loss rate is greater than the nitrogen loss rate, and may further aggravate the carbon loss in the soil. The influence of the soil physical and chemical properties in the mountainous area is only related to the interaction between the disturbance of the ammonia nitrogen and the space area, and the disturbance of other physical and chemical indexes is not affected by the difference in the spatial area, which implies that the earthquake may be affected by the soil profile Vulnerable and disturbed soil physical and chemical properties of the impact of changes in the types of ecological and climate changes on the physical and chemical properties of the soil on the landslide may be a relatively long-term process.