滇西北地区蕨类植物物种多样性和区系组成

Species diversity and floristic composition of pteridophyte in Northwest Yunnan

利用大尺度的蕨类植物分布信息和野外考察资料,探讨了滇西北地区蕨类植物的物种多样性及其区系组成。结果表明,滇西北地区分布有蕨类植物50科,136属,624种,是中国蕨类植物最为丰富的地区之一。蕨类植物的优势科主要包括鳞毛蕨科Dryopteridaceae、水龙骨科Polypodiaceae和蹄盖蕨科Athyriaceae等;优势属主要包括鳞毛蕨属Dryopteris、耳蕨属Polystichum和铁角蕨属Asplenium等。在科、属、种的水平上,热带区系成分始终占据主导地位,表明研究区域内蕨类植物的区系起源可能与热带蕨类区系之间存在着密切的联系。但从科水平到属和种的水平,热带区系成分所占比重有所降低,这可能与不同分类阶元所代表的地质历史和研究区域的地壳抬升历史有关。研究区域内分布着中国特有蕨类植物物种205种,明显高于周边其他地区,这暗示着滇西北地区可能是云南地区蕨类植物中国特有种分布最为集中的地区之一。在科和属的层次上,滇西北地区蕨类植物均表现出较强的区系分化特征,这可能与研究区域内复杂的地形和特殊的地质历史有关。

Based on field work and distribution information of pteridophyte at large scale, we investigated the species diversity and floristic composition of pteridophyte in Northwest Yunnan. Our results showed that the study area harbored 624 species, subordinated in 50 families and 136 genera, and was one of the richest regions of pteridophyte in China. Predominant families were Dryopteridaceae, Polypodiaceae and Athyriaceae, et al. Predominant genera were Dryopteris, Polystichum and Asplenium, et al. At family, genus and species level, tropical elements always dominated floristic composition, suggesting strong linkage between their origination and the flora in tropical regions. However, from family to genus and species level, the decrease of tropical elements may be associated with the study area＇s geological history and different geological histories represented by different taxonomical levels. The study area had 205 species endemic to China, which was significantly higher than neighborhood regions. It may imply that the study area may be one of the diversity centers of endemic pteridophyte in China. At family and genus level, pteridophyte in Northwest Yunnan showed strong specification, which may link with its complex topography and geological history.