中文摘要：

松嫩草地盐碱化严重。在一定的土壤电导率值和pH值范围内，羊草能够正常生长。羊草草地退化演替的过程中，羊草的光合色素总量、叶绿素总量、类胡萝卜素含量均发生变化。不同退化演替过程中羊草叶片光合色素在不同生育期呈相似的变化趋势。伴随着草地退化的加重。羊草光合色素总量和叶绿素含量呈现下降趋势。但是出现了叶绿素a/b、类胡萝卜素特异性增加的现象。通过统计学分析表明，羊草叶片光合色素总量、叶绿素含量与羊草种群的形成有密切的关系。

英文摘要：

The salt - alkaline degree of Songnen grassland is serious.Leymus chinensis can grow well when the pH and conducfivity of grassland are in certain range. With the degenerating succession of L. chinensis grassland, the total amount of photosynthetic pigments, chlorophyll and carotenoid changed. The change tendency of photosynthetic pigments of L. chinensis is similar in different growth stages when the L. chinensis grassland is degenerating. With the grassland degenerating seriously, the amounts of photosynthetic pigments and chlorophyll have a decline tendency. But the chlorophyll a/b and the amount of carotenoid are all increase specially. The statistic result showed that the relationship between the amount of photosynthetic pigents and chlorophyll, and the form of L. chinensis population is close.