典型滩涂环境因子对植物群落空间分布的影响

长江口滩涂生境具有较高的环境异质性,导致不同滩涂植物群落的分布特征存在显著差异。为分析长江口典型滩涂植物群与环境因子的关系,在崇明东滩和奉贤金汇港两个典型滩涂对其环境因子及植物群落特征进行了采样分析。分析结果表明,滩涂随着高程的增加,受潮汐的影响逐渐减少,环境因子呈现一定的规律性变化,滩涂植物对环境因子具有不同的适应力是导致长江口盐沼植被带状分布的重要因素。崇明东滩作为植物群落较为成熟的滩涂,芦苇和互花米草的生长表现沿高程呈"V"型。奉贤金汇港作为植物建群较短的新生带滩涂,互花米草的生长表现沿高程呈梯度分布。两区域植物群落表现不同的主要原因有可能是建群时间、演替阶段、滩涂受潮汐作用和立地条件等造成的。

Impact of typical tidal flats environment factors on spatial distribution characteristics of plant community

Because of the relatively high environmental heterogeneity in tidal flats of Yangtze River estuary, the distribution characteristics of plant communities in different tidal flats are notably different. To analyze the relation between plant community and typical tidal flat environment factors, samples of environmental factors and plant communities in two typical tidal flats in Chongming Dongtan and Fengxian Jinhuigang were respectively collected for study. The result shows that with the increase of tidal flat elevation, the influence of the tide reduces gradually, the environmental factors changes regularly along elevation. One of the important factors leading to zonal distribution of salt marsh vegetation in Yangtze River estuary is the different adaptability of tidal flat plants to environmental factors. As the plant community is relatively mature in Chongming Dongtan, the growth performance of Phragmites australis and Spartina alterniflora along the elevation is in V shape. As the plant community is newborn and rela-tively young in Fengxian Jinhuigang, Spartina alterniflora growth performance presents a gradient distribution along the elevation. The main causes for the different growth performance of plant communities in two areas are likely to be different constructive time, different succession stage, different tidal action, and different site conditions.