云贵高原及横断山区莲座蕨科植物地理分布特征及其格局成因初探

Analysis on the Geographical Distribution Characteristics of Angiopteridaceae and Its Causes in Yungui Plateau and Hengduan Mountains, China

依据云南大学植物标本馆蕨类植物标本室(PYU)和国内主要标本馆保存的莲座蕨科植物标本,以及多年来积累的研究资料,建立该科植物在云南的产地GIS数据库。以此为基础,分析云南莲座蕨科植物空间分布的多样性和特有性,及其在云贵高原及横断山区的地理分布特征。研究结果如下:①云南莲座蕨科植物种类丰富,分布海拔范围为100～2400m;②滇东南是莲座蕨科植物分布的多样性和特有性中心,其多样性由滇东南向西、北方向递减;③云南有莲座蕨科2个属分布,即莲座蕨属(Angiopteris)和原始莲座蕨属(Archangiopteris),其中原始莲座蕨属的物种多样性较低而特有性较高。初步分析了该科植物中5个广布种和1个高山峡谷种分布格局的成因,以及5个特有种的发生史,推断广布种的分布格局形成于第四纪冰期之前,高山峡谷种的分布格局形成于第三纪之后,而特有种的主要成因可能是自然杂交和边缘效应。

According to the specimens of the Angiopteridaceae reserved in PYU, PE, KUN, and IBSC, and other published data, a GIS database of Angiopteridaeeae had been established to analyse the diversity and endemism of species in Yunnan Province, China. Furthermore, the characteristics of geographical distribution of the Angiopteri- daeeae in Yungui Plateau and Hengduan Mountains were illustrated. The results were as follows： i. Angiopteridaceae had diverse species and were widely distributed in Yunnan, from alt. 100 m to alt. 2 400 m; ii. Southeastern Yunnan was the center of species diversity and endemic distribution, and species diversity declines from southeast towards west and northwest in Yunnan; iii. Comparing 2 genera of Angiopteridaceae in Yunnan, Archangiopteris was relatively lower in species diversity but its endemic level was higher than Angiopteris. Next, the causes driving the distribution pattern of 5 wide-spread species and 1 species that growing only in valley habitat, as well as the distribution pattern of 5 endemic species were analysed. As an elementary conclusion was made, the distribution pattern of the wide-dis tributed species was formed before the Quaternary glaciation, and the pattern of valley species was formed after the Tertiary. Meanwhile, the speciation of endemic species was mainly due to natural hybridization and edge effect.