塔里木河中游水盐梯度下的物种多样性研究

根据塔里木河中游5个断面30眼地下水监测井和30个植物样地2006—2008年调查监测的数据,分析了输水堤防修建后地下水埋深、地下水质以及物种多样性的变化及其相互关系。结果表明：地下水埋深的空间变化表现为沿河道方向先增加后减小的趋势,在时间上则表现为,从2006年到2008年埋深呈逐渐增加的特点;地下水化学类型的变化,在空间上表现出沿着河道方向有由Cl-—SO42-—Na＋—Mg2＋向Cl-—Na＋类型转变的趋势,在时间上,地下水矿化度逐渐增加。物种多样性总体上呈现增加变化,地下水位和水质对塔里木河中游物种多样性变化有着密切的关系,地下水埋深2.8~3.7 m,矿化度1.8~2.4 g·L-1水平下的多样性较高,随着地下水埋深的增大和矿化度的升高,物种多样性水平降低。

Variations in species diversity with the gradients of depths and quality in groundwater at the middle reaches of Tarim River

Based on the data of depths and quality of groundwater as well as species diversity collected from 2006 to 2008,the eco-logical effects of dam construction at the middle reaches of the Tarim River were studied.It is found that the longitude variations in groundwater depths were increase first and decrease then.The temporal variations in groundwater depths were increase gradually.The spatial variations in the chemical type of groundwater varied from Cl--SO42--Na ＋-Mg2 upwards to Cl--Na ＋ downwards.Like the annual changes of groundwater,the total dissolved solids（TDS） in groundwater increased step by step.Unlike the declining of groundwater depths or the deteriorating of groundwater quality,the species diversity increased generally.Variations in species diver-sity have close relations to both the depths and the quality of groundwater,the species diversity is optimum with the groundwater depths varying from 2.8 m to 3.7 m and TDS in groundwater varying from 1.8 g.L-1to 2.4 g.L-1.