和田河上游灰杨不同林型土壤理化性质及酶活性分析

Physicochemical Properties and Enzymatic Activities of Different Populus pruinosa Forest Types in the up Reaches of Hotan River

以和田河上游灰杨不同林型0~100cm土壤为研究对象,探讨4种林型土壤理化性质、土壤酶活性空间变化规律。结果表明,4种林型土壤含水率、全盐量空间异质性较为明显。土壤容重随着土层加深表现出先增大后减小趋势,不同林型容重均值大小排序为Ⅱ〉Ⅰ〉Ⅲ〉Ⅳ。不同林型土壤含水率均值变化则与容重相反,林型Ⅱ各土层含水率均为最低。4种林型土壤pH值介于8.15~9.17之间,林型Ⅱ各土层全盐含量均为最低,林型Ⅰ、Ⅲ、Ⅳ土壤全盐量表现出表层聚集现象。在4种林型中,有机质含量随着土层加深变化均表现出先增大后减小的趋势,在60~80cm土壤层有机质含量均最高。在不同土层中,过氧化氢酶、脲酶均以林型Ⅲ活性最强,蔗糖酶、碱性磷酸酶则以林型Ⅳ活性最强,过氧化氢酶、脲酶、蔗糖酶在土层60~80cm活性最高。经相关分析和主成分分析表明,容重、含水率与其他测定指标相关性较强,水分指标在第1主成分中所占比重较大,对外界环境变化比较敏感。土壤结构、水分条件是影响和田河上游不同灰杨林型土壤特征的主要因子。

In order to probe the spatial change rules of soil physicochemical properties and soil enzyme activities,0~ 100 cm soil profiles of 4 Populus pruinosaforest types in the upstream of Hotan River were used as the research objects.The results showed that the spatial heterogeneity of the moisture content and total salt were more obvious than the other determined indexes in 4 types.The bulk density firstly increased then decreased with the depth of soil layers of 4 types.The order of average bulk density values was typeⅡⅠⅢⅣ,while the reversed order was observed in soil moisture content.The pH values were between 8.15 ~ 9.17 in 4 types.The soil salt content was the lowest in typeⅡ,and the soil salt gathered the topsoil in typeⅠ,Ⅲ,andⅣ.Organic matter firstly increased then decreased as the soil depth in the 4 types,highest in 60~80cm soil layer.In different soil layers,the activities of catalase and urease were the strongest in typeⅢ,while the activities of invertase adn phosphatase were the strongest in type Ⅳ.Catalase,urease and invertase activities were the highest in 60~80cm soil layer.Correlation analysis and principal component analysis showed that the bulk density and soil moisture content had a strong correlation with other measured indexes,the moisture indexes accounted for a large proportion in the first principal component,and it was sensitive to the change of external environment.Soil structure and soil moisture conditions had important influence on the other soil properties in the different P.pruinosatypes in the upstream of the Hotan River.