西宁市南北山主要造林树种的土壤水分特征研究

Soil Moisture Characteristics of Major Afforestation Tree Species in North and South Mountains of Xining City

为探讨西宁市南北山典型造林树种的土壤水分特征,揭示不同树种对土壤水分的影响程度,选取西宁市南北山绿化工程区为典型造林树种为研究对象,以天然草地作为对照,通过采集土壤样品,并测定其含水率及物理性质,分析不同造林树种下的土壤水分变化特征。结果表明,不同植被类型条件下土壤含水率大小依次为天然草地(15.40%)>人工灌丛(14.19%)>人工油松林(13.01%)>人工云杉林(12.16%)>人工杨树林(11.77%),土壤物理性质表现为人工杨树林>人工油松林>人工云杉林,且0~100 cm土层内土壤水分随林龄、林分结构及立地条件改变而存在差异,并出现土壤水分亏缺现象。根据西宁市南北山不同植被类型条件下土壤水分变化特征,采取合理的乔灌草搭配模式进行人工造林是维持土壤水分平衡的关键。

In order to explore the soil moisture characteristics of typical afforestation tree species in North and South Mountains of Xining City and reveal the influence of different tree species on soil moisture,the typical afforestation tree species in the North and South Mountains Greening Project Area of Xining City were selected as the research object,and the natural grassland was used as a control to analyze the soil moisture change characteristics under different afforestation tree species by collecting soil samples and measuring the water content and physical properties.The results showed that the soil moisture contents were natural grassland(15.40%)>artificial shrubland(14.19%)>artificial Pinus tabuliformis forest(13.01%)>artificial Picea crassifolia forest(12.16%)>artificial Populus forest(11.77%),soil physical properties were artificial Populus forest>artificial Pinus tabuliformis forest>artificial Picea crassifolia forest,and the soil moisture within 0-100 cm of soil layer varied with the changes of forest age,stand structure and site conditions,and soil moisture deficiency occurred.Therefore,according to the characteristics of soil moisture changes under different vegetation types in North and South Mountains of Xining City,artificial afforestation with a reasonable arbor shrub and grass matching mode was the key to maintaining soil moisture balance.