博斯腾湖西岸湖滨带不同植被类型土壤剖面盐分特征分析

以博斯腾湖西岸湖滨带为研究区,通过野外调查采样和室内实验分析,运用聚类分析、主成分分析和相关分析等方法对5种不同植被类型土壤(柽柳地、芦苇地、裸地、杨树地、辣椒地)剖面盐分类型、含盐量变化特征及盐分离子组成特征进行分析。结果表明:土壤剖面盐分类型可以划分为表聚型、震荡型、均匀型3类。柽柳地与裸地的土壤剖面类型为表聚型,其土壤剖面变异系数为61.28%,表聚系数是底聚系数的4.45倍,表层聚集现象严重;芦苇地的土壤剖面盐分类型为震荡型,变异系数为30.05%;辣椒地和杨树地的土壤剖面盐分类型为均匀型,变异程度最小仅为表聚型剖面的47.65%。5种不同植被类型土壤剖面平均盐质量分数呈现柽柳地裸地芦苇地辣椒地杨树地,其中柽柳地平均盐质量分数为2.67g/kg,与杨树地土壤平均盐质量分数之比为2.45。5种不同植被类型土壤剖面盐分组成以Na~++K~+、SO_4~(2-)、Cl~-为主,阳离子平均质量分数呈现Na~++K~+Ca~(2+)Mg~(2+),阴离子中总体表现SO_4~(2-)Cl~-HCO-3,盐分状况的主要特征因子为Cl~-、SO_4~(2-)、Na~++K~+、总盐(St),土壤剖面盐分以氯化钾钠盐和硫酸钾钠盐为主,Cl~-与Na~++K~+相关系数为0.941,SO_4~(2-)与Na~++K~+相关系数为0.884;盐分状况因子Cl~-、SO_4~(2-)、Na~++K~+、St与电导率均呈显著正相关(P0.05),电导率与Na~++K~+回归拟合效果较好,拟合关系式为y=0.039 5x+0.218 6,R2=0.966 7,P0.05。

Analysis of Salinity Characteristics of Different Vegetation Types in Soil Profile in Western Side of Bosten Lake of Xinjiang

Taking the western side of Bosten Lake as the study area, the characteristics of salt types, salt mass fraction and salt ion composition of soil profiles of five planting types were analyzed based on field investigation, sampling and laboratory analysis, by using cluster analysis,principal component analysis and correlation analysis.The results showed that the salinity types of soil profiles could be classified into three types:surface accumulation profiles, oscillatory profiles and equably distribution profiles.The soil profile types of Tamarix ramosissima filed and bare field were the surface accumulation profiles,the coefficient of variation of soil profile was 61.28%, and the surface aggregation phenomenon was serious, which the surface polymerization coefficient was 4.45 times of the bottom aggregation coefficient, the salinity of soil profile type in Phragmites australis was oscillatory profiles, the soil profile types of Capsicum and Populus field were profiles with equably distribution, which the degree of variation was the smallest, only 47.65% of the surface accumulation profiles. The average salt mass fraction of soil profile under five different vegetation types could be:Tamarix ramosissima field>bare field>Phragmites australis field>Capsicum field>Populus field, and average salt mass fraction of Tamarix ramosissimafield soil was 2.67 g/kg,the average soil salinity ratio of Tamarix ramosissima field to Populus field was 2.45.The salt composition of soil profile under five vegetation types was dominated by Na⁺+K⁺, SO^2-₄ and Cl^-,the average mass fraction of cations could be :Na⁺+K⁺>Ca²⁺>Mg²⁺,while the anions were generally could be:SO^2-₄ >Cl^->HCO^-₃,the main characteristic factors of salt status were CI-, SO^2-₄, Na⁺+K⁺ and total salt(S_t).The salt mass fraction of soil profile was mainly composed of potassium chloride, sodium salt and potassium sulphate,the correlation coefficients of Cl^-, SO^2-₄ and Na⁺+K⁺ were 0.941,0.884. Cl^-, SO^2-₄, Na⁺+K⁺,S_t and soil conductivity showed a significant positive correlation(P<0.05),the regression fitting results of conductivity and Na⁺+K⁺was better, the fitted relation was:y=0.039 5x+0.218 6,R=0.966 7( P<0.05).