祁连山排露沟小流域土壤物理性质空间差异研究

研究了国家重点野外观测试验站--祁连山森林生态站排露沟流域土壤物理性质及其空间差异.结果表明:(1)土壤容重随深度而变化,变化幅度大小顺序为:山地栗钙土＞山地森林灰褐土＞亚高山灌丛草甸土,不同类型土壤容重变动在0.45～1.38 g/cm3之间;(2)土壤总孔隙度大小顺序为:亚高山灌丛草甸土＞山地森林灰褐土＞山地栗钙土,不同植被下土壤总孔隙度表现出不同的差异;土壤毛管孔隙在不同植被下,各层之间无显著性差异;土壤非毛管孔隙,山地栗钙土与亚高山灌丛草甸土和山地森林灰褐土之间存在显著性差异(P＜0.05).(3)土壤最大持水量大小顺序为:山地森林灰褐土＞亚高山灌丛草甸土＞山地栗钙土;毛管持水量与含水量均表现出亚高山灌丛草甸土＞山地森林灰褐土＞山地栗钙土,各类型土壤含水量均随海拔的升高而增大.

Soil Physical Characteristics in Pailugou Watershed of Qilian Mountains

Soil physical characteristics and its spatial variation were studied in Pailugou watershed located in Qilian Mountains Forest Ecology Monitoring Station belonging to the State Key Field Scientific Experimental Station. Results showed that (1) Soil physical characteristics changed with soil depth and the change extent was in the order of sub-alpine shrub meadow soilforest gray-brown soilchestnut soil. (2) Total soil porosity varied dramatically with different vegetation types. The total soil porosity of sub-alpine shrub meadow soil was higher than forest gray-brown soil,and in turn,chestnut soil. There was no significant difference in soil capillary porosity under different vegetations. For soil non-capillary porosity,there was significant difference among chestnut soil,sub-alpine shrub meadow soil,and forest gray-brown soil from the viewpoint of geographical spatial difference (P0.05). (3) The soil water holding capacity of forest gray-brown soil was higher than sub-alpine shrub meadow soil and chestnut soil. As for soil capillary capacity,sub-alpine shrub meadow soil was the highest,followed by forest gray-brown soil and then chestnut soil. Soil non-capillary porosity varied dramatically with different degrees of vegetation cover. As for natural moisture content,sunny slope is significantly different among all vegetation types. Sub-alpine shrub meadow soil is the highest,followed by forest gray-brown soil and chestnut soil. Sub-alpine shrub soil had good structure and texture and greater potentiality for water conservation. Natural moisture content of all the soil types was increased with elevation.