中国西南与台湾地区维管植物的间断分布格局及形成机制

植物的间断分布格局及其形成机制是植物地理学研究的重要问题之一。本文在对中国大陆与台湾名录整理比较的基础上,对中国西南与台湾地区的植物间断分布格局及形成机制进行了分析。结果表明,两地同种型间断分布的维管植物有198种(包括变种和亚种),隶属于56科129属,其中蕨类植物86种,裸子植物3种,双子叶植物56种,单子叶植物53种;两地异种型间断分布的维管植物有22属,隶属于15科,其中蕨类植物6属,裸子植物1属,双子叶植物7属,单子叶植物兰科8属。间断分布类群以草本植物为主,主要是蕨类和兰科植物。间断分布类群在台湾地区主要分布在中部到东北部,在大陆的分布主要集中在川东–鄂西地区、川西–滇西北地区–藏东南地区和滇东南–桂西–黔西南地区。在垂直高度上,海拔1,550–2,350m是间断分布类群最集中分布的海拔范围。我们推测中国西南与台湾地区的间断分布类群有3种来源:北半球温带、中国西南和热带亚洲来源。

Disjunct distribution of vascular plants between southwestern area and Taiwan area in China

Disjunct distributional patterns and the formative mechanisms resulting in distinct flora has been an important focus in the field of phytogeography. In this study, we compared vascular plant checklists of the Chinese mainland and Taiwan, and analyzed the formation mechanisms of the discontinuous taxa between southwestern area and Taiwan area in China. We documented 198 total species (including infraspecies) in 129 genera and 56 families disjunctly distributed in southwestern area and Taiwan area in China, among which 22 genera in 15 families have species-pairs with a disjunct distribution between the two regions, including six genera of ferns, one of gymnosperm, seven dicotyledons, and eight monocotyledons. The disjunct taxa are mainly herbaceous, most of which are ferns and orchids. These disjunct taxa are mainly distributed in the center-northeastern Taiwan area, and three regions of the mainland China, including eastern Sichuan–western Hubei, western Sichuan–northwestern Yunnan–southeastern Xizang, and southeastern Yunnan–western Guangxi–southwestern Guizhou. These taxa are generally distributed along an altitudinal gradient ranging from 1,550 m to 2,350 m. We believe that these disjunct patterns may have been derived from three possible origins including a northern temperate origin, southwestern China origin, and/or tropical Asia origin.