Flora characteristics of vascular plants in wetland nature reserves in Beijing

In order to find out the distribution rules and characteristics of vascular plant flora in wetland nature reserves in Beijing, floristic types of vascular plants were analyzed and compared based on the data investigated at Baihebao Lake, Hanshiqiao Lake, Huaishahe River and Huaijiuhe River, Jinniuhu Lake, Jumahe River and Yeyahu Lake during year 2003-2005. Vascular plants were classified into four groups: water plants, dank plants, amphibian plants and aridly plants. Recent situation of invasive species and distribution characteristics of typical wetland plants were analyzed. There are 314 species, belonging to 74 families and 193 genera; a large part of genera are temperate, tropical and cosmopolitan types in flora analyzing; six nature reserves were partitioned into three groups based on the characteristics of flora; Polygonum lapathifolium, Mentha haplocalyx, Glycine soja, Inula japonica, Amethystea caerulea and Phragmites australis distribute widely in the nature reserves, while Acorus calamus, Spardanium stoloniferum and Eclipta prostrara distribute more straitly; in addition, 11 invasive plants are recorded without baneful quarantine species. Spread of amphibian and aridly plants is caused by the scarcity of water resources in Beijing; transition area of land and water is one of the primary elements leading to the differences of species richness and floristic types; in order to avoid more loss, some invasive species should be paid more attention to right now.