夏尔希里自然保护区草地表层土壤理化性质与海拔高度的关系

Study on the Relationship Between Physical and Chemical Properties of Grassland Surface Soil and Altitude in Xarxili Nature Reserve

为了探究夏尔希里自然保护区草地表层土壤理化性质与海拔高度的关系,在保护区内选取具有代表性的草地样地共15个,以不同海拔高度土壤为试验材料,采用野外调查与室内试验相结合的方法,对保护区草地表层土壤理化性质进行定量分析。结果显示:在不同海拔高度上,草地表层土壤物理性质指标之间差异显著(P<0. 05)。土壤容重、饱和含水率、自然含水率、孔隙度均与海拔高度呈极显著相关(P<0. 01),土壤容重随海拔升高逐渐降低,在海拔2142.24m处出现最小值,为0.91g cm^-3。在不同海拔高度上,草地表层土壤化学指标之间差异显著(P<0. 05),土壤有机质、全氮、全磷质量分数变化范围为3. 72%~11. 98%、1. 25%~3. 25%、0. 121%~0. 159%,且均随海拔高度升高而逐渐增加,在海拔高度2142.24m处出现最大值,而pH值变化规律与其相反。不同海拔高度处草地表层土壤理化性质不同,在海拔高度2142.24m处草地表层土壤理化性能总体最好,在海拔高度835.23m处最差。从不同土壤类型看,草地表层土壤理化性能综合表现为黑钙土>栗钙土>棕钙土。

To explore the relationship between physical and chemical properties of grassland surface soil and altitude in the Xarxili Nature Reserve,15 representative grassland surface soil samples were acquired from different altitudes in the protected area and the physical and chemical properties of the soil samples were quantitatively analyzed by field investigation and laboratory tests. The results show that there were significant differences(P<0. 05)in soil physical property indices in the grassland surface at different altitudes. Soil bulk density,saturated moisture content,natural water content, and porosity content were significantly correlated with altitude(P<0. 01),and soil bulk weight decreased gradually with the increasing of altitudes,having a minimum value of 0. 91 g·cm^-3 at 2 142. 24 m. There were also significant differences in chemical indices of the grassland surface soil at different altitudes(P<0. 05). The variation ranges of soil organic matter,total nitrogen,and total phosphorus mass fractions were 3. 72%-11. 98%,1. 25%-3. 25%,and 0. 121%- 0. 159%,respectively,all increasing with the increase of altitude. The maximum values were observed at the altitude of 2 142. 24 m. However,the pH value changed in the opposite direction. The physical and chemical properties of grassland surface soil varied with different altitudes with the best at the altitude of 2 142. 24 m and the worst at the altitude of 835. 23 m. For different soil types,the physical and chemical properties of grassland surface soil comprehensively manifest in the order of black calcium soil > chestnut soil > brown calcium soil.