岷江冷杉原始林土壤物理性质的海拔梯度变化

Change of soil physical properties along elevation gradients in Abies faxoniana natural forest

为探明岷江冷杉原始林土壤物理性质与海拔梯度的关系，以卧龙邓生阴坡岷江冷杉原始林沿海拔梯度2700～3600 m内设置的样地调查数据为基础，分析土壤密度、土壤孔隙度、土壤持水性能和土壤石砾含量随海拔梯度的变化。结果表明，相同海拔下土壤密度随土层深度增加明显增大，各土层土壤密度随海拔升高出现先升高后降低的变化趋势，但差异不显著；土壤总孔隙度和毛管孔隙度随着土层深度的增加有所减小，但减小不明显。相同海拔下土壤含水量、毛管持水量、最小持水量、最大持水量等随土层深度增加呈现显著性减小；不同海拔梯度岷江冷杉原始林下土壤总孔隙度和毛管孔隙度的差异不显著，导致土壤含水量、毛管持水量、最小持水量、最大持水量等也呈现出不显著的变化趋势，土壤石砾含量与土层深度和海拔高度的关系也不显著。

Based on the data collected from sample plots in a Abies f axoniana natural forest along altitude from 2 700 m to 3 600 m , soil density , relationship of soil physical properties in a Abies f axoniana natural forest and elevation gradients are studied . The results show that at the same altitude soil density significantly increases with increasing soil depth , soil density in each soil layer increases first and then decreases with elevation gredientsgradients with a less significant difference . Total porosity and capilary porosity unobviously decrease with increasing soil depth with elevation . Soil water content , capillary holding capacity , minimum water‐holding capacity , maximum water‐holding capacity significantly decrease with the depth of soil layer increased . An insignificant change of total porosity and capilary porosity at different altitudes result in an insignificant change of soil water content , capillary holding capacity , minimum water‐holding capacity , maximum water‐holding capacity , gravel content do not change regularly with soil layer and altitude .