Floristic Geography Of Vascular Plants In Encheng National Nature Reserve

Through many in-depth field investigations in Encheng National Nature Reserve,collecting and identifying specimens,consulting relevant documents and materials,and sorting out relevant investigation data,to understand the geology and geomorphology,climatic characteristics and vegetation types of Encheng National Nature Reserve,and analyze the characteristics of plant species composition,floristic properties and endemic phenomena in Encheng National Nature Reserve.The rare and endangered plant species are evaluated according to the IUCN evaluation standard,the reasons for the threat are analyzed,and the corresponding protection countermeasures are put forward according to the actual situation.The main results of this study are as follows:1.There are 1777 species of vascular plants(including 47 cultivated species)in Encheng National Nature Reserve,belonging to 185 families and 844 genera,including149 species of pteridophytes(using Qin Renchang system),belonging to 32 families and57 genera,10 species of gymnosperms(using Zheng Wanjun system),belonging to 6families and 8 genera,and 1618 species of angiosperms(using Hutchinson pine system),belonging to 147 families and 779 genera.2.There are 149 species of pteridophytes in Encheng Nature Reserve,which belong to 32 families and 57 genera according to Qin Renchang(1978)system,accounting for50.79%,24.68% and 5.73% of the total pteridophyte species of 63 families,231 genera and 2600 species in China.Taking Polypodiaceae,Pteridaceae,Thelypteridaceae,Aspleniaceae and Adiantaceae as the dominant families in this area,there are 80 species,accounting for 53.69% of the total number of pteridophytes in this area.Pteris,Adiantum,Asplenium,Selaginella,Colysis,Pyrrosia,Cyclosorus,Lygodium and Microsorum are the dominant genera,with a total of 75 species,accounting for 50.34% of the total species of ferns in this area.The ferns in this area are dominated by tropical and subtropical properties.3.The species of wild gymnosperms in Encheng National Nature Reserve are relatively poor,with only 10 species,belonging to 6 families and 8 genera,accounting for3.33%,0.98% and 0.58% of wild vascular plant families,genera and species in this area.4.There are 1581 species of angiosperms in Encheng National Nature Reserve,belonging to 148 families and 763 genera.The dominant families of angiosperms in this area are Euphorbiaceae,Fabaceae,Asteraceae,Rubiaceae,Orchidaceae,Gramineae,Moraceae,Urticaceae,Acanthaceae,Verbenaceae,Labiatae,Liliaceae,Gesneriaceae,Vitaceae,Lauraceae,Caesalpiniaceae,Cucurbitaceae,Rosaceae,Asclepiadaceae,Rutaceae,Myrsinaceae,Begoniaceae,Rhamnaceae,a total of 417 genera and 946 species,accounting for 50.85% and 54.68% of the total genera and species of angiosperms in this area,respectively.There are 185 dominant genera,accounting for 10.69% of the total species of angiosperms in this area,including Ficus,Begonia,Carex,Ardisia,Rubus,Tetrastigma,Rostellularia,Ophiopogon,Jasminum,Spiradiclis,Piper and Bauhinia.The wild seed plants in this area are mainly tropical and subtropical.5.The flora of Encheng National Nature Reserve has obvious tropical nature,mainly tropical and subtropical components.The pteridophyte families in this area are tropical and subtropical except those distributed in the world,and there is no temperate distribution.The genera and species of tropical and subtropical distribution account for 91.11% and96.15% of the total number of pteridophyte genera and species in this area respectively(except families and genera distributed in the world),and the proportion of temperate distribution components of genera and species is 10.26: 1 and 24.97: 1 respectively.The families and genera of tropical distribution of seed plants in this area account for 74.07%and 79.69% of the total number of families and genera of wild seed plants in this area,respectively(except families and genera distributed in the world),and the proportion of temperate distribution components of families and genera is 4.21: 1 and 4.25: 1,respectively.6.The species of most families and genera in this area are relatively poor,mainly single-species families and genera and few families and genera.There are 22 families of single species and few species(2?4 species)of pteridophytes,accounting for 68.75% of the total families,and there are 48 genera of single species and few species,accounting for84.21% of the total genera of pteridophytes.There are 101 families of single species and few species(2?10 species)of seed plants,accounting for 56.11% of the total families of wild seed plants in this area,and there are 724 genera of single species and few species(2?5 species),accounting for 88.29% of the total number of wild seed plants in this area.7.There are many rare and endangered plants in Encheng Nature Reserve,including 4species of national I key protected plants,38 species of national II key protected plants,66 species of key protected plants in Guangxi,including 55 species of Orchidaceae.According to the endangered grades and standards of IUCN species Red list and the threatened species list of higher plants in China,a total of 140 species were classified as threatened species according to the endangered grades of IUCN species Red list of wild vascular plants in Encheng Nature Reserve.8.Two new species of Breynia enchengensis S.Y.Nong,Y.S.Huang ? Yan Liu,sp.nov.and Bredia enchengensis J.H.Dai,Yan Liu ? S.Y.Nong,sp.nov.have been found in the reserve,and two new record in Guangxi,namely Smilax elegantissima Gagnepain and Vitis romaneti Roman.var.tomentosa.9.The common plants in Encheng National Nature Reserve were arranged to provide a species identification map for the reserve.