湖南八大公山的植物区系及其在植物地理学上的意义

FLORA OF HUNAN BADAGONGSHAN MOUNTAINS AND ITS PHYTOGEOGRAPHICAL SIGNIFICANCE

湖南八大公山自然保护区是华中地区面积大且植物保存较完好的地点。土著种子植物计１６２科、７０９属、１７７５种。全部属按１５个地理分布型进行分析，全部种按更细的分布型类别（中国特有分为１０个亚型）进行分析。结果表明，本地热带分布的科属虽为数不少，但温带分布的科属更显优势，北温带科属比较集中，同时中国、东亚、及东亚－北美特有属也很集中。本山中国特有种计１１２０种，华中特有种为３４７种。植物区系的古老、残遗及特有性突出，可视为中国（华中）有典型代表性的山地。

Badagongshan Mountains is a national nature reserve in Central China, It is situated at29°30'-29°50'N.latitude,109°42'-110°10'E. longitude in Sangzhi county,north-western Hunan province. The total area of the mountain is about 250 km￣2.Its nature forest occur at about 1200 m to 1890 m elevation. The dominant elements in the forest are Fagus,Quercus,Cyclobalanopsis,Carpinus,Betula,Sassafras,Tila, Acer,Padus,Davidia,Rhododendron,Sinanrundinaria etc. On the top of the mountains,Fagus lucida almost form pure forest. 1.Based upon the statistics of the plants of Badagongshan,there are 1775 species including varieties of 709 genera in 162 families of seed plants(excluding cultivated species,the same below).A comparison to the flora of other mountains of southern China (see Table 1),shows its distinct bio-diversities of species.Moreover,the flora is also rich in woody plants, with 923 spe-cies in 299 genera,making up 52% of the total plant species. 2. The phytogeographical characteristics of all plants in this area are analyzed and discussed at the different levels (families,genera and species).The 30 large families,being 63.3% of the to-tal species and containing number of endemic species are listed in Table2,in which the temperate families slightly predominate over the tropical families.In addition,a lot of families of Eastern Asia,E. Asia-North America and Chinese endemic a real-type are more concentrate in the area,most of them are archaic and relic elements.3.According to the differences of a real types of 709 genera of seed plants in the mountains,14(15)a real types are listed in Table 3 and some comparisons are made with other similar moun-tain regions in southern China. As shown in Table 3,in the Badagongshan both temperate and tropical genera are nearly equally abundant.Anoteworthy characteristics in phytogeography is that the a real types of E. Asia,E. Asia-N. America,and Chinese endemics are more concen-trated in this area, with 210 genera,making up 31.8% of the total.Many of them are monotypicand oligotypic,and its archaic and relic characteristics are very obvious. 4.Moreover,according to the statistics of species,a real type 1120 species belong to Chinese endemic and 396 species belong to E. Asia type, both of which amount to 1516 species,being85.4% of the total species.Among the species endemic to China, 347 species belong to Central Chna endemics.Due to the concentration of the numerous archaic. relic and endemic elements,the Badagongshan should be considered as a typical area,in which,the North Temperate,the E.Asia,the E. Asia-N. Americal and the other a real types can be closely interconnected.Based up-on the same reason,the Badagongshan can be also considered as a core area in Central China,as well as in China,with more typical representatives.