武陵山地区种子植物区系特征及植物地理学意义

武陵山地区地处湘鄂川黔交界，面积约10万km2，从科，属，种水平对区种子植物区系特征进行研究，结果表明，（1）该区产种子植物201，1005属，4119种，地理成分以亚热带（至温带）分布为主（占总属数的56．8％和总种数的90．49％），中国特有属64属，中国特有种达2682种（其中武陵山地区特有126种，武际人山区以外的华中区特有675种）。（2）该区保存有长苞铁极，水杉，粗榧，厚朴，鹅掌楸，水青属，八角莲属，马蹄芹属等起源或重要化化地；（3）该区与邻近区系具有广泛交流和渗透，经初步确定分别有109种，96种，67种和109种以武 陵山地区为分布区东界，西界，南界和北界，另外所含东亚成分由西向东方向分布式样的359种中，有303种正处于该方向迁移和扩散的重要通道（武陵山走廊）上，因此，武陵山地区在中国植物区系甚至个东亚植物区系中具有十分重要的意义。

Characteristics ofSpermatophyte Flora of Mt^Wulingshan Region from Central China and Its PhytogeographicalSignificance

Mt.Wulingshan region locate at 27°28′～30°05′N and 107°02′～111°33′E,covering an area of about 100 000 km+2.The altitude ranges from 189.4 m to 2 570 m. This paper reported the results of study on floristic feature of the spermatophytic flora of Mt.Wulingshan region.The results showed:① The flora was considerably rich.There are 4 119 species belonging to 1 005 genera and 201 families.The subtropical-temperate geographical elements of genera was dominant(56.8 of the total genera and 90.49 of total species),in which 64 genera and 2 682 species were Chinese endemic (among them 126 species are endemic to Mt. Wulingshan and 675 species were endemic to Central China);② The flora was rich of relic species and original taxa,e.g.Metasequoia glyptostroboides,Liriodendron chinense,Eucommia ulmoides,Euptelea pleiospermum,etc.Moreover,some families and genera,such as Helwiniaceae,Davidiaceae,Taiwania, Asteropyrum, Dysoma,etc.Probably originated form Mt. Wulingshan and its neighboring regions;③ The flora of Mt. Wulingshan had extensive relationship with surrounding floras.Our analysis indicated that Mt. Wulingshan was probably situated at a special distribution boundary, e.g. it was the east,west,south and north boundary of 109,96,67 and 109 species,respectively;④ Based upon the distribution patterns and migration routes of some East-Asian elements, Mt. Wulingshan region was one of the key region of the East|Asian elements.Among 359 species which migration patterns being mentioned by Wang Wen-cai as from the west to the east,303 species presented in this region.Further,Mt.Wulingshan as an important floristic channel,i.e.Wulingshan channel is considered.