额济纳绿洲不同植被覆盖下土壤特性的时空变化

Spatio-temporal Characteristics of Soil in Ejina Oasis

额济纳绿洲地处干旱内陆河地区。在分析额济纳绿洲土壤特性的基础上,以不同植被类型下的土壤作为分析对象,根据观测的土壤含水量数据及环境因子的观测数据,研究了额济纳绿洲土壤水分的时空变化规律,分析了土壤水分变化与环境因子之间的关系,建立了土壤含水量与环境因子之间的回归模型。研究结果表明,土壤剖面土壤类型及结构差异较大,土壤类型的差异主要受成土条件的制约和外部自然环境的影响,戈壁地区与其他几种植被类型下的土壤差异最为显著;土壤类型及结构的差异,土壤容重变化的特性及土壤水势、土壤含水量的变化,直接影响着植被的生长和分布;额济纳绿洲不同植被类型下的土壤含水量变化差异显著;土壤含水量的季节变化分析表明,土壤剖面中不同层的土壤含水量变化也存在着一定的差异,可以分成不同的稳定变化层,急剧变化层和相对稳定层;土壤含水量的日变化受环境因子的影响较为明显,空气温湿度、土壤温度及地下水水位埋深是影响土壤含水量最为显著的因素。

Ejina Oasis is located in a typical arid region.Based on observational data of soil moisture and environmental factors,this article studied the spatio-temporal characteristics of soil moister of different vegetation cover types in Ejina Oasis,analyzed the relationship between soil moisture and environmental factors,and then established regression functions of soil moisture and environmental factors.The results are as follows.Soil types and soil structure are quite different in different environments,and they are mainly affected by soil conditions and external environment.Soil type in Gobi is obviously distinct with the other vegetation cover types.Variation of soil types,soil structure,soil bulk density,soil potential and soil moisture affect vegetation growth and distribution.The soil moisture of different vegetation cover types varies significantly,and the moisture in different soil layers is different too,and soil profile can be divided into stability layer,dramatic change layer and relatively stable layer.Daily variation of soil moisture is significantly impacted by the environmental factors,especially,air temperature,air humidity,soil temperature and ground water level are the most significant factors.