为了明确叶尔羌河流域上游段(莎车县段)、中游段(麦盖提县段)和下游段(夏河林场段)土壤盐分对胡杨生长的限制程度，对胡杨林分因子(密度、冠幅、树高、盖度、胸径)进行野外调查，并分层采集土壤样品，利用SPSS20。0和Canoco5。0软件对土壤盐分离子和胡杨林分因子进行单因素方差分析、Pearson分析和RDA排序分析，明确土壤盐分离子空间分布特征对胡杨林分因子的影响。结果表明:叶尔羌河流域不同河段不同土壤深度的盐分离子含量存在差异，其中表层(0～20cm)土壤总盐以及Cl-、SO42-、Ca2+、Mg2+和K++Na+盐分离子的含量均显著高于20 cm以下各层。土壤盐分离子间存在相关性，其中SO42-、Ca2+、Mg2+和总盐均与Cl-具有极显著正相关关系;Mg2+与SO42-具有显著正相关关系，K++Na+和总盐均与SO42-具有极显著正相关关系;总盐与Ca2+具有显著正相关关系;K++Na+与Mg2+具有显著正相关关系;总盐与Mg2+具有极显著正相关关系;总盐与K++Na+具有极显著正相关关系。胡杨林分因子的分布特征为密度、盖度和胸径是下游＞中游＞上游，树高和冠幅是上游＞下游＞中游;密度在上游属中等强度变异，在中游和下游的变异程度较弱;胸径在中游和下游属于中等强度变异，上游变异程度较小;胡杨盖度、株高和冠幅在上游、中游及下游的变异程度均较低。胡杨林分因子间具有相关性，其中密度与盖度为极显著正相关关系;株高与胸径呈显著负相关关系，与冠幅呈极显著正相关关系;胸径与冠幅呈显著正相关关系。80～100 cm Ca2+、60～80 cm K++Na+和20～40 cm SO42-是胡杨林分因子特征的主要限制因子。
Spatial distribution of soil salinity ion and its influence on stand factors of Populus euphratica in Yarkant River Basin
In order to clarify the limitation of soil salinity on the growth of Populus euphratica in the upper reaches(Shache County section),middle reaches(Maigaiti County section)and lower reaches(Xiahe Forest Farm section)of Yarkant River Basin,stand factors(density,crown width,tree height,coverage,diameter at breast height)were collected by field investi-gation and soil samples were collected by stratification.Single-factor ANOVA,Pearson analysis and RDA sequencing analysis were performed to determine the effects of soil salinity ion spatial distribution on the stand factors of Populus euphratica using SPSS20.0 and Canoco5.0 software.The results showed that there are differences in the content of salt ions in different depths of soil in different reaches of the Yarkant River Basin,and the contents of total salt and Cl-、SO42-、Ca2+、Mg2+、K++Na+in the sur-face layer(0-20 cm)are significantly higher than those in the layers below 20 cm.There is a significant positive correlation a-mong soil salinity ion.SO42-,Ca2+,Mg2+and total salt are positively correlated with Cl-.Mg2+is positively correlated with SO42-,while K++Na+and total salt are positively correlated with SO42-.There is a significant positive correlation between total salt and Ca2+.There is a significant positive correlation between K++Na+and Mg2+.There is a significant positive correlation between total salt and Mg2+.There is a significant positive correlation between total salt and K++Na+.The distribution characteristics of Populus euphratica stand factors are density,coverage and breast diameter are downstream＞midstream＞upstream,and tree height and crown width are upstream＞downstream＞midstream.The variation of bulk density is moderate in the upper reaches and weak in the middle and lower reaches.The breast diameter is moderately variable in the middle and lower reaches,and the variation in the upper reaches is small.The variation degree of coverage,plant height and crown width of Populus euphratica in upstream,midstream and downstream is low.There is a correlation among the stand factors of Populus euphratica,and there is a significant positive correlation between density and coverage.There is a significant negative correlation between plant height and breast di-ameter,while a very significant positive correlation with crown width.There is a significant positive correlation between breast diameter and crown width.Ca2+(80-100 cm),K++Na+(60-80 cm)and SO42-(20-40 cm)are the main limiting factors of Popu-lus euphratica stand factor characteristics.
Yarkant River Basinstand factors of Populus euphraticasoil salinity ioncorrelation analysis
万方数据
维普
