拉林铁路沿线灌丛草地土壤理化性质及可蚀性K值研究

Study on Soil Physicochemical Properties and Soil Erodibility in Shrubland along the Lalin Railway

探讨拉林铁路沿线灌丛草地土壤理化性质及可蚀性的空间分布特征,为今后沿线植被恢复和生态保护提供理论数据基础。选取沿线6个典型样地,每个样地设置在距离铁路500~1000 m位置,采集0~20 cm土壤,测定团聚体特征、有机质及颗粒组成,并通过EPIC模型,计算土壤可蚀性K值。结果表明:(1)拉林铁路沿线土壤理化性质存在差异,非水稳性和水稳性团聚体均以>0.25 mm为主,团聚体破坏率值在7.56%~25.65%之间,有机质含量在15.34 g·kg^(-1)~26.89 g·kg^(-1)之间,颗粒组成以粉砂粒为主;(2)沿线土壤可蚀性K值变化范围为0.1044~0.2973,均值为0.2147,属于中等可蚀性等级;(3)土壤可蚀性K值与黏粒、粉粒含量呈正相关关系;与砂粒含量呈负相关关系;与有机质含量呈负相关关系,与>0.25mm非水稳性团聚体和水稳性团聚体含量均呈负相关关系,与团聚体破坏率呈正相关关系。在修复及恢复损坏的土壤及植被时,应降低土壤砾石含量,提高土壤有机质。同时,减少人为影响程度,加强土壤自身稳定性,使生态系统得到自我恢复。

To provide theoretical data basis for vegetation restoration and ecological protection along the Lalin Railway,the spatial distribution characteristics of soil physical and chemical properties and erodibility were discussed in shrubland.Six typical plots were selected along the line,and each plot was set at 500-1000 m away from the railway,and then 0~20 cm soils were collected and the agglomerate characteristics,organic matter and particle composition were analyzed,meanwhile,the soil erodibility(K value)was calculated using EPIC Model.The results showed as follows:(1)The physical and chemical properties of soil along the Lalin Railway were different.The non-water-stable and water-stable aggregates were mainly>0.25mm,and the agglomerate destruction rate was between 7.56%and 25.65%.The organic matter content was between 15.34g·kg^(-1) and26.89g·kg^(-1),and the particle composition was mainly composed of silt particles.(2)The soil erodibility K value along the line varies from 0.1044 to 0.2973,with a mean value of 0.2147,which was a moderately erosive grade.(3)Soil erodibility K value was positively correlated with clay and silt content,negatively correlated with sand content,negatively correlated with organic matter content,negatively correlated with>0.25mm non water stable aggregate and water stable aggregate content,and positively correlated with aggregate failure rate.In order to repair and restore the damaged soil and vegetation,the content of soil gravel should be reduced and the soil organic matter should be increased.Also,the degree of man-made influence should be reduced and soil stability should be enhanced to make ecosystem recover by itself.