中文摘要：

以天鹅洲湿地的优势种红穗苔草（Carex argyi）作为研究对象,以淹水持续时间作为水位变化的衡量指标,选取3个淹水持续时间不同的位点,研究了淹水时间长短对红穗苔草形态指标的影响。通过野外原位观测试验发现,红穗苔草的株高及叶片的长、宽对淹水时间的长短反应敏感,而单个分株上的绿叶数对淹水时间的长短不敏感。适度的淹水可以显著增加叶片的长度和株高,长期淹水和相对干旱的环境不利于叶片的伸长和株高的增加。短时间淹水处理株高一直维持较高的水平,并保持相对的稳定。淹水会显著增加叶片的宽度,长时间淹水的处理效果更明显,且维持时间较长。长期淹水会提高红穗苔草地上部生物量的分配比例。尽管不同水位点土壤氮含量有显著差异,但是氮对红穗苔草形态指标并无显著的影响。以上实验结果表明,红穗苔草可以通过调节其叶片的形态及地下和地上部分生物量的分配比例来适应淹水胁迫的不利环境,有利于其在水位波动条件下种群的稳定和维持。

英文摘要：

We choose three different inundation sites（long-term inundation,short-term inundation and no inundation） to investigate the morphological responses to temporal inundation of a perennial grass Carex argyi,a dominant species in Swan Islet Wetland,China.The results showed that plant height,leaf length,and width of leaf blade were sensitive to inundation.This sensitivity was different among the three sites.Plant height and leaf length were increased from short-term inundation but were inhibited under long-term or no inundation.Plant height reached a maximum before and after inundation and remained steady.Long-term inundation facilitated leaf extension and leaf blade width and increased the above-ground biomass of the species.Although total soil nitrogen concentration was significantly different among different sites of inundation,it had no significant effect on these sensitive characteristics of this species.Our results indicated that C.argyi could adjust their leaf shapes and resource allocation patterns to inundation at the temporal scale,which might benefit population maintenance and stability.