摘要
水蓼(Polygonumhydropiper)是一种分布于三峡地区消落带的常见物种。通过模拟4—5月的水淹节律,研究了水蓼对水淹的生理生态学响应机理。结果表明,各处理所有的植株存活率都保持100%。水淹改变了水蓼的日光合作用和日蒸腾作用节律,在水淹条件下的植株一天中能比对照更长时间地保持高水平的光合速率,短期水淹下植株的蒸腾速率呈"双峰"曲线,而对照和长期水淹下的植株则呈"单峰"曲线。植株在水淹条件下生长其光合速率和蒸腾速率都显著高于对照,但是随着水淹时间的延长这种增加效应会有所下降。植株叶片光合色素含量在水淹条件下也会发生显著变化,短期水淹使得光合色素含量增加,但随着水淹时间的延长,光合色素含量逐渐降低,长期水淹条件下,色素含量低于对照,由于植株能形成大量不定根,长期水淹对植株的生理活动并没有显著的负面影响。因此水蓼是一种比较耐淹的一年生草本植物,模拟水淹不仅没有影响到植株生长发育,在一定程度上还促进了植株的生理活动。文章最后结合三峡库区消落带未来生态环境的变化分析了该物种分布状况的变化趋势及其在消落带生态治理中的应用潜力。
Polygonum hydropiper, a widely distributed species in natural water-level-fluctuating zone in the Three Gorges area, plays an important role in soil protection and riverbank stabilization. Its ecophysiological response to simulated flooding from April to May was studied by this paper in order to uncover effects of the Three Gorges Project on it and to search whether it can be used in the restoration of degraded riverbank vegetation. Results showed that all plants of the species survived under different flooding treatlnent, and that the daily transpiration dynamics of plant was changed from ＂single peak＂ to ＂two peaks＂ along with the flooding time form 10 d increased to 30 d. The photosynthesis of flooded plants was higher than the control plants during afternoon. The average photosynthesis rate and average transpiration rate of plant were increased significantly during the primary flooding time. However, the increasing decree reduced along with the prolongation of flooding time. The photosynthetic pigment contents of chlorophyll a, chlorophyll b and carotenoid were also increased by short time flooding whereas reduced by long time flooding. All of those suggest that Polygonum hydropiper is a species which favorites growing on the simulated fluctuating condition and can adapt to the future water-level-fluctuating zone in the Three Gorges area. But, as an annual species, its distribution in the future water-level-fluctuating zone will depend on the emerging time and season which decided whether it has enough time to finish its life history.
出处
《生态环境》
CSCD
北大核心
2008年第3期1096-1099,共4页
Ecology and Environmnet
基金
国家科技支撑计划课题项目(2006BAC10B01)
关键词
水蓼
消落带
光合作川
蒸腾作川
Polygonum hydropiper
water-level-fluctuating zone
photosynthesis
transpiration
