灾害干扰受损区自然恢复初期土壤物理性质的变化特征

Change Characteristics of Soil Physical Properties at the Initial Natural Recovery Stage in Disaster Disturbed and Damaged Areas

以洪涝诱发灾害干扰受损区的次生阔叶林、杉木林和毛竹林为研究对象,研究了3种林型自然恢复过程中土壤容重、孔隙度和田间持水量等11项土壤物理性质指标的变化规律及主要影响因素。结果表明:(1)次生阔叶林和杉木林在未受损-刚受损-受损恢复过程中土壤容重先增大后减小,毛竹林逐渐减小;次生阔叶林和杉木林总孔隙度、含水率、饱和持水量、毛管持水量和田间持水量先减小后增大,毛竹林逐渐减小;3种林型土壤质地先变粗后变细。(2)通过相关性分析和主成分分析,发现含水率、毛管持水量和田间持水量可作为评价灾害干扰受损区土壤物理性质恢复能力的主要指标。(3)通过主成分分析和因子分析得出,3种林型土壤抗蚀性在未受损-刚受损-受损恢复过程中先减小后增大,受损自然恢复状态土壤抗蚀性从大到小依次为杉木林、次生阔叶林、毛竹林。研究结果可为灾害干扰受损区土壤物理性质变化规律及土壤恢复机制提供理论依据。

Taking the secondary broad-leaved forest,Cunninghamia lanceolata forest and Phyllostachys heterocycla forest in the flood disaster disturbed area as the research objects,the change characteristics and main influencing factors of 11 soil physical properties,including soil bulk density,porosity,field capacity and so on,in the process of natural restoration were analyzed.The results showed that:(1)During the process of undestroyed-destroyed-natural recovery,soil bulk density of secondary broad-leaved forest and C.lanceolata forest increased first and then decreased,while that of P.heterocycla forest decreased gradually.The total porosity,moisture content,saturated water-holding capacity,capillary water-holding capacity and field water-holding capacity of secondary broad-leaved forest and C.lanceolata forest decreased first and then increased,while those of the P.heterocycla forest gradually decreased.The soil texture of three forest types became coarse and then fine.(2)According to the results of correlation analysis and principal component analysis,moisture content,capillary water-holding capacity and field water-holding capacity could be used as the main indicators to evaluate the recovery capability of soil physical properties in the damaged area.(3)According to the results of principal component analysis and factor analysis,soil erosion resistance of three forest types decreased first and then increased in the process of undestroyed-destroyed-natural recovery,and the soil erosion resistance at the stage of natural recovery followed the order of C.lanceolata forest>secondary broad-leaved forest>P.heterocycla forest.This study provided a theoretical basis for the study of the change rules of soil physical properties and soil recovery mechanisms in the disaster disturbed area.