中文摘要：

湿地植物群落是湿地生态系统的重要组分，是湿地生态系统的主要初级生产者，维持和承载着湿地生态系统各种各样的物理过程和生物功能，其结构、功能和生态特征能综合反映湿地生态环境的基本特点和功能特性。湖泊湿地水位波动及其带来的环境梯度变化对湿地植物群落的影响是生态学中的重要问题之一。本研究通过2010年10月到2012年2月在鄱阳湖南矾湿地设置57个固定样方开展植物群落的高度、植物种类、数量，优势种高度及植物的物候学特征逐月观测，研究了鄱阳湖南矶湿地植物群落生长发育过程以及植物群落时空变化特征，并且对这些特征的可能形成原因以及其和鄱阳湖水位波动的关系等进行了探讨。结果认为，受鄱阳湖水位周期性波动和湿地植物自身特性等因素的影响，鄱阳湖南矾湿地植物群落生长、发育、繁殖等过程都与鄱阳湖水位波动密切相关；植物群落空间上沿距湖岸的远近、高程和水位梯度呈现出明显的环带状分布或弧状分布格局；时间上表现出明显的季相变化特征。

英文摘要：

Wetland plants are an important component of wetland ecosystems. Ecological characteristics of wetland plant communities can comprehensively reflect the basic structure, functioning, and health status of an ecosystem. Most of previous research in the Poyang Nanji Wetlands has only qualitatively described responses of wetland plants to fluctuations in lake water levels. Quantitative studies in that ecosystem are still rare. In this paper, we report on quantitative studies that were conducted in the wetlands from October 2010 to February 2012. We conducted monthly surveys of spatial variations in, and distributions of plant community characteristics, and correlated such characteristics with fluctuations in lake water levels. Fifty-seven fixed quadrats at 3 Sub-lakes in the Poyang Wetlands were used. The surveys included individual counts and measurements of plant height, and plant phenological characteristics （germination percentage, flowering, and developmental stages, fruiting and withering state）. Plant community composition and characteristics changed with the seasons and hydrological fluctuations in the wetlands. Plant communities had the following characteristics： （1）Biological： developed aerenchyma, strong clonal growth and reproductive capacity, special leaf type and structure for adapting to the aquatic environment, and diversification of life forms; （2） Floristic composition： rich species, complexity of the flora, diversity types, and strong herb plants （3） Community composition： eight major plant communities （4） Spatial distribution of plant communities： banded, mosaic or arc-shaped distribution along the water level and elevation gradient （5） Spatial distribution of plant communities： plant community composition and characteristics varied with the seasons and hydrological fluctuations. We also found that plant community characteristics varied with fluctuations （frequency and amplitude） in water levels of the lake.