A Foristic Study On Angiosperms Of The Wetlands In Yunnan,China

Wetlands,known as the "kidney" of the earth,are an important ecosystem.As an important part of "Water tower of China" and "Water tower of Asia",Yunnan wetland plays an important role in ecosystem service function.In this paper,based on the specimens and field investigation,the angiosperm flora of Yunnan wetland was statistically analyzed at the levels of family,genus and species.The main conclusions are as follows:1)Wetland plants are rich in Yunnan.In total,there are 1280 species,varieties or subspecies which belong to 420 genera and 92 families.2)The angiosperm floristic elements of the Yunnan wetland are complex.Almost all kinds of distribution types are more or less represented here.In the region,the total of 92 families can be divided into 7 types;the total 420 genera can be divided into 14 types and 5 subtypes;the total 1280 species,varieties or subspecies can be divided into14 types,4 subtypes,and 5 forms.3)The floristic characteristic of angiosperms of the Yunnan wetlands is temperate,but it is greatly influenced by tropical elements.Within the total 92 families in the region,tropical families are 33(35.9% of the total families,excluding cosmopolitan families),temperate families are 20(21.7% of the total families).Within the 420 genera,tropical genera are 153(36.4% of the total genera,excluding cosmopolitan genera),temperate genera are 209(49.8% of the total genera).Within the 1280 species,varieties or subspecies,tropical species are 339(26.5% of the total species,excluding cosmopolitan species),temperate species are 928(72.5% of the total species).4)At the level of genera in angiosperms of Yunnan wetlands flora,pantropic distribution pattern is the richest among tropical distribution patterns.Among temperate distribution patterns,north temperate and East Asia distribution are richest.From the standpoint of all of China,the flora of the region is closely linked with the flora of the Sichuan by the occurrence of 144 species that are common between the two regions.From the standpoint of all of East Asia,flora of the region is closely linked with the flora of the Himalayas by the occurrence of 256 species that are common between the two regions.5)The flora of Yunnan wetlands presents a high level of endemism,there are 10 endemic genera to China,accounting for 2.4% of the total genera,and 425 endemic species to China,accounting for 33.2% of the total species.Among them,143 species are endemic to Yunnan,accounting for 11.2% of the total species.6)The flora of the Yunnan wetlands is part of the Eastern Asian flora.In the floristic division of Eastern Asia,it was put into East Himalayan region,Sino-Himalayan forest subkingdom.In the region,at the level of genera,Eastern Asian genera are 41(9.8% of the total genera),of which Sino-Himalayan genera are 26(63.4%of the total Eastern Asia genera).At the level of species,Eastern Asian species are 358(28% of the total species),in which Sino-Himalayan species have 256 species(71.5% of the total Eastern Asia species).