波动和静止水文情势下小叶章(Calamagrostis angustifolia)的生理生态特征

通过野外调查与控制试验相结合的方法,比较研究了波动和静止两种水文情势下,沼泽化草甸植物--小叶章(Calamagrostis angustifolia)某些生理生态特征(种群密度与高度、叶长、叶宽、茎长、节长以及叶绿素含量)对不同水分条件的响应.结果表明,不同水文情势对小叶章生理生态特征具有明显的影响.波动水文情势下,小叶章种群、形态指标及叶绿素含量总体随水分的增加而减小或下降,但是由于特定水文情势下形成的群落竞争格局的影响,小叶章单优群落分布带上小叶章各指标值明显大于其它水分带;静止水文情势下,小叶章各指标值呈波动变化,30 cm积水处理下的种群密度、高度、叶宽和茎长以及叶绿素含量与其它处理差别显著.波动水文情势下小叶章各指标测定值均大于静止水文情势下的,同一生活史阶段要较静止水文情势下的提前,生长能力较强.湿地水分条件不仅直接影响植物特性,还通过影响植物定植的土壤环境特征及群落内的竞争格局间接作用于植物.不同水分条件下,小叶章的生理生态特征是水分条件直接与间接作用的综合结果.

A comparison of some eco-physiological characters of Calamagrostis angustifolia under variable and static water regimes

Ecol-physiological characters including population density and height, leaf length and width, culm lenth, internode length and chlorophyll content of Calamagrostis angustifolia were studied using field survey and controlled experiment for two water regimes. Different responses of C. angustifolia to water regimes were detected. The values of above indicators decreased as the water level increased under the variable water regime. However, for the different composition of communities resulted from different water conditions, these indicators reached the maximum on the zone occupied by C.angustifolia community. In contrast, under static water regime, these indicators showed a wave-like change, population density and height, leaf width, culm length and chlorophyll content in the treatment with static water level of 30 cm were significantly different from other treatments. Under variable water regime, C. angustifolia grew better and its growing stage came earlier than under static water regime. In wetlands, water conditions not only affected directly the growth of plants, but also indirectly influenced by the composition of communities and soil characters. Therefore, ecol-physiological characters of C.angustifolia were the results of both direct and indirect functions of different water conditions.