中文摘要：

松嫩草地生产力同时受到降水和土壤盐碱化的制约,但是在降水变化的背景下土壤盐碱化与草地生产力的相关性仍不清楚。本文基于松嫩草地降水的带状分布特征和野外样地调查数据,分析了不同降水量地区土壤盐碱化与羊草生物量的相关性,并利用系统聚类分析法对每个调查区土壤pH值、电导率和容重进行聚类,划分出盐碱胁迫低、中和高3个类群,探讨不同降水区土壤盐碱化指标对羊草地上生物量影响的变化趋势。结果表明：不同降水区,羊草生产力与土壤盐碱化指标间相关性不同。降水较高的草地东部和降水较少的西南部羊草地上生物量和土壤容重呈显著负相关,降水适中的草地中西部羊草地上生物量和土壤pH值呈显著负相关,羊草生物量总体随着盐碱胁迫呈负指数衰退,但各降水带内衰退主要因子和衰退影响程度有所不同。

英文摘要：

Productivity of Songnen grassland is affected by precipitation and soil salinization, but the corre- lation between soil salinization and grassland productivity is still not clear in the context of precipitation change. Based on the distribution characteristics of rainfall belt and field investigation data in Songnen grassland, the correlation of soil salinization and biomass of Leymus chinensis in different precipitation area were analyzed. Analysis of each investigation area of soil pH value, conductivity and bulk density by sys- tematic cluster analysis method, salt stress degree was divided into three groups： low, middle and high, respectively. And the change of soil salinization indicator in different precipitation areas on the aboveground biomass of Leymus chinensis was discussed. The results showed that in different precipitation areas, there was different correlation between productivity of Leymus chinensis and soil salinization indicator. The aboveground biomass of Leymus chinensis was significantly negatively correlated with soil bulk density in the higher precipitation of the eastern and the lower precipitation of the southwest, and the aboveground biomass was significantly negatively correlated with soil pH value in moderate precipitation of the midwest. In general, there was an exponential decay of the biomass of Leymus chinensis with the increase of saline and alkaline stress, but the main factor and impacting degree of recession at the precipitation zones were different.