Flora Of Seed Plants In Dehang Geopark Of Hunan Province

A comprehensive survey of seed plants was conducted in Dehang Geopark.The list of Seed Plants in Dehang Geopark was sorted out combining field investigation(more than 1400 former specimens and 2000 new specimens were collected and over 20000 photos were taken),relevant literatures and CVH digital specimens.Meanwhile,this thesis analysized and discussed the characteristics and features of the seed plants flora in Dehang Geopark.The main research result and conclusions were shown as follows:(1)There was high species diversity of Spermatophyta in Dehang Geopark.Our investigation showed that there are 1626 species of wild seed plants belonging to 154 families,710 genera.These plants accounted for 94.48%,83.43% and 53.56% of seed plants families,genera and species in Wulingshan region,and for 73.33%,54.20% and33.46% in Hunan Province.Dominant families of trees included Rosaceae?Lauraceae?Theaceae?Rutaceae?Fagaceae,etc.while Asteraceae?Poaceae?Fabaceae?Lamiaceae?Urticaceae,etc.are dominant families of shrubs and herbs.(2)The floristic analysis showed that the geographical element of seed plants in Dehang Geopark was complex.There exited 12 area-types of families,14 area-types of genera,and 15 area-types of species in this region,The area-type of families was mostly pan-tropic families,and followed by north temperate families.As for the area-type of genus,pan-tropic and north temperate genus were dominant.For species,the number of endemic to China and East Asian species(including var-types)is the largest,which reflects that the flora has obvious characteristics of East Asian flora.(3)The flora of Dehang Geopark exhibited obvious endemism.The area contained7 endemic families in East Asia,2 endemic families in China,27 endemic genera in China,and 588 species endemic to China,including 39 species endemic to Central China,18 species endemic to Wulingshan region,and 6 species endemic to Dehang Geopark(Sinosenecio jishouensis?Aster jishouensis?Quercus dehangensis?Yushania dehangensis?Lysimachia xiangxiensis?Aspidistra fenghuangensis).The distribution of endemic genera and species showed that the flora is closely related to that of East China,Central China and South China,and tended to extend to the South and East.(4)Two new species,Quercus dehangensis and youngia wulingshanensis were found in Dehang Geopark,and three new record species,Viburnum punctatum,Aristolochia dabieshanensis and Sanicula were found as new records of Hunan Province.The discovery enriches the background plant resources in Dehang Geopark,and is of great significance to the study of flora in this area.(5)There were obvious differences in floristic composition in different habitats.There were only 14 common species in the three habitats.The species of the geographical distribution in three typical habitat were mainly endemic to China and East Asia distribution.Comparison to other eight regions showed that species richness in Dehang Geopark was at the lower middle level.It was also found that families,genera and species of seed plants in Dehang Geopark were highly similar with those in Huping Mountain,Xiaoxi and Wulong Mountains.(6)Dehang Geopark was rich in rare and endangered plant species.A total of 84 rare and endangered plant species from 65 genera and 40 families were recorded in this area.Among them,67 species were included in the IUCN Red List,and 41 species were included in the National Key Protected Wild Plants List,which indicates that seed plants in Dehang Geopark are of high scientific value and need further protection.In conclusion,Dehang Geopark are one of the typical representatives of central subtropical mountain flora in China and even in East Asia,thus analysis of flora in Dehang Geopark is of essential importance for further analyzing the flora in areas of Wulingshan region.Meanwhile,Dehang Geopark is one of the ideal areas for studying the differentiation of floristic composition in special habitats.Therefore,Dehang Geopark are of great research and conservation value.