黄河三角洲3种生境下的芦苇形态差异及生理生态特征研究

Morphological Variations and Physiological Characteristics of Phragmites australis in Three Habitats in Yellow River Delta

为阐明3种自然生境下的芦苇适应环境策略,通过设置样地,研究水生、湿生、旱生生境下芦苇的形态性状及生理生态特征,结果表明:(1)芦苇的最高高度、平均高度、最高冠幅、平均冠幅和盖度以水生生境最大,湿生生境次之,旱生生境最小;多度值以旱生和水生生境条件下较大;在水生条件下,芦苇往往形成单优势种群。(2) 3种生境中的芦苇横走茎主茎长度不同,随地下水位下降,各分支无性系分株数量、分株高度和叶片数增多,分株距离、分株直径和叶面积减小;随着水分限制的加强,芦苇的节数和根数量增多,节长和根长变短。(3)在旱生生境下,根部和叶部SOD、POD活性和根部CAT活性显著高于水生和湿生,叶部CAT活性旱生显著低于水生。3种生境叶部MDA含量表现为旱生>湿生>水生,湿生和旱生生境下,根部MDA含量明显高于水生。这些形态性状的差异及生理生态特征可以看作芦苇对3种生境的适应性表现。

An experiment was conducted to study the adaptive strategies of Phragmites australis by designing the differentexperiment habitats.The results showed that:(1)For the maximum height and the average height, the highest crown and the average crown, and the coverage of P.australis , aquatic was the biggest, next was hygrophilous, the xeromorph was smallest, and the abundance in the xeromorph environment was similar to the aquatic condition.(2)Different caulis length appeared in different habitats, and with water content descending, the number of sucher increased, the height of sucher reduced.There was a gradual reduction in leaf area and diameter of sucher, with water stress increasing, the node number reduced, the length of node became shorter, the root lengh reduced, and thetotal of roots increased.(3)In the xeromorphic condition, the activities of SOD, POD of enzymes of roots and leaves and the activities of CAT were significantly higher than those of the aquaticand hygrophiloushabitats.In three different habitats, the MDA content of the xeromorph and hygrophilous habitats were significantly higher than those of the aquatichabitats.The morphological variations and physiological characteristics of these traits might have resulted from adaptability of P.australis in three habitats.