Flora of Higher Plant in Wetland of Beijing Area

Researches on wetland plants of Beijing area mainly began in 1990s,but studies on the flora characteristics of higher plants of wetland in Beijing area has not yet been reported.Based on data collection,information inquiry and field survey,the features and characteristics of the flora of higher plants of wetland in Beijing area were analysed.The study of floristic element has supplied sufficient basis of developing,utilizing and preventing the local plant resources,as well as developing plant introduction from other basin or areas.Five hundred and fifty two species of higher plants belonging to 311 genera and 108 families(including mountain wetland) were distributed and approximately counts for about 1/3 of the total plants in Beijing district.Those families,genera and species covered 48.87% of the families,32.06% of the genera and 23.40% of the species of higher plants in Beijing region,respectively.Among them,Bryophytes were 18 species belonging to 15 genera and 9 families,occupied 3.26% of the total species;and Pteridophgtes were 8 species belonging to 5 genera and 5 families,occupied 1.45% of the total species;and Gymnospermae were 6 species belonging to 5 genera and 3 families,occupied 1.09% of the total species;and Angiosperms were 520 species belonging to 286 genera and 91 families,accounting for 94.20% of the total number of the higher plants of wetland in Beijing area.From the statistics of relative great families,5 greater families(species≥20)were the principle parts of all the higher plants.The total was 210 species,occupied 38.04% of total species,and Compositae,Poaceae,Cyperaceae,Leguminosae,and Polygonaceae were the greatest families.From the statistics of relative great genera,there were 14 greater genera(species≥5),the total was 114 species,accounted for 4.50% of total genera and 20.65% of total species.Polygonum,Artemisia,Cypeus,Rumex,and Carex were the greatest genera in Beijing wetland.The distribution of wetland plants in Beijing was complex.The moss plants species had 3 areal-types,the fern plants species had 2 areal-types,and Holarctic kingdom was the main type.The flora of Beijing wetland seed plants could be divided into 15 distribution types and 9 subtypes,and Cosmopolitan and North Temperate were the two main types.179 species belong to Cosmopolitan,and 149 species belong to North Temperate,occupied 34.03% and 28.32% of total species,respectively.On the other hand,63 species belong to Pantropic,49 species belong to Old World Temperate,occupied 11.98% and 9.32% of total species,respectively.The type of Temperate occupied an leading position,the element in temperate zone was very rich(genera,species and proportion all play an important role).The area department of plants had the following features : ① it was the development of herb;② there was a dominance of temperate species;③ it was age old in origin;④ endemic species was poor;⑤ its geographical elements were complex.