于田绿洲土壤pH值的空间异质性及其对芦苇生长的影响研究——以喀尔克乡为例

Spatial Variability of Soil pH value and Its Effects on the Growth of Phragmites Australis in Keriya Oasis——Taking Karki Village as an Example

选择新疆于田绿洲喀尔克乡西侧的带状芦苇地为研究区,基于区域变量理论,用地统计学的变异函数、Krigmg空间插值和经典统计学的相关分析,定量分析芦苇分布区不同层次土壤pH值的空间变异性及其与芦苇生长之间的相互关系。结果表明:芦苇分布区土壤0～50cm之间,各层土壤为碱性和强碱性土壤,均没有酸性土壤;随着土壤深度的增加碱性土壤的数量逐渐增加,强碱性土壤则相反。芦苇分布区土壤pH值的垂直分布较稳定,0～10cm、10～30cm和30～50 cm等三层土壤pH值的变异系数均小于10%,属弱变异性。芦苇分布区土壤pH值的水平分布来看,东部高于西部;土壤pH值从东部向西部逐渐降低;除了西南边也有些高值区外,高值区基本上出现在研究区的东边;高值区面积在0～10cm土层中比较大,其次是10～30cm土层,最小的是30～50cm土层;可知,高值区面积随着土壤深度的增加逐渐减小,但是高值区出现的部位基本不变。随着土壤深度的增加,土壤pH值的等值线趋于简单,空间分布均一化。土壤pH值与芦苇生长之间的相关性研究表明,芦苇株高和芦苇冠幅长受三层土壤pH值抑制影响较其他三项生长指标大;芦苇株高和芦苇冠幅长受0～10cm层土壤pH值抑制影响较它们受10～30cm和30～50cm两层土壤pH值抑制影响大。

Spatial variation of soil pH value and the correlation between the growth of phragmites aust- rails and pH value of different soil layers were analyzed quantificationally, based on the regionalized varia- ble theory, using semivariograms of geostatistics, Kriging method and correlation analysis of statistics, choosing a phragmites land on the western part of Karki village as a study area. Results showed that soils in the study area are mainly alkaline soils and strong alkaline soils; Amount of alkaline soil and the propor- tion of alkaline soil to whole on every soil layer increase with the increase of soil depth; strong alkaline soil is the opposite. Soil pH values in study area are quite stable; Variation coefficient of soil pH value on 0- 10cm,10-30cm and 30-50cm soil layers are all under 10%, belongs to weak variability. Soil pH values on eastern part of the study area were larger than the soil pH values on the western part of the study area; Soil pH values decrease from eastern part to the western part of the study area; High values of soil pH val- ue were mainly distributed on the eastern part of the study area while there was a small area of high values of soil pH value on the western south of the study area; The biggest area of high values of soil pH value was distributed on the 0-10cm layer, the second big area of high values of soil pH value was distributed on the 10-30cm layer, the smallest one was distributed on the 30-50cm layer; The area of high values of soil pH value decrease with the increase of soil depth, but the positions of high values of soil pH value ba- sically are same; Contour maps and the spatial variation of soil pH values were simplified with the increase of soil depth. The effects of soil pH value on those three layers on the density and crown length of phrag- mites australis are larger than the effects of it on the other three growth index of phragmites australis; The effects of soil pH value on 0-10cm layer on the density and crown length of phragmites australis are larger than the effects of soil pH value on other two soil layers on them.