云南地区种子植物热带亚洲区系成分的地理分布格局

On Geographical Patterns of Trop.Asia in Flora of Seed Plants in Yunnan,Southwest China

该研究以相对完整的植物区系分布信息为基础,利用统计学分析方法结合地理信息系统平台,探讨了云南地区种子植物区系中热带亚洲区系成分的地理分布格局.结果表明:总体上热带亚洲区系成分所占比例从南到北呈递减趋势.爪哇、喜马拉雅间断或星散分布到华南、西南分布亚型和热带印度至华南(尤其是云南南部)分布亚型所占比例从东到西呈递增趋势,而越南(或中南半岛)至华南(或西南)分布亚型所占比例的经度格局则呈现出相反的变化趋势.热带亚洲区系成分在云南地区的扩散方向以南—北向为主,其次为东—西向.滇东南地区植物区系组成不同于滇南和滇西南植物分区.虽然"田中线"对于热带亚洲区系成分的总体分布具有明显的限制作用,但是对各亚型的限制作用却不尽相同.在区系成分的亚型层次上探讨"田中线"的限制作用,可能有助于更深刻、全面地理解其成因和限制作用.

Geographical patterns of Trop. Asia in flora of seed plants in Yunnan, Southwest China have statistically been investigated based on all-around flora information and geographical information system. The overall proportions of Trop. Asia decreases with the increase of latitude. An increasing trend has been observed on the proportions of Java, Himalaya to S. , SW. China disjuncted or diffused and Trop. India to S. China （esp. S. Yunnan） with the decrease of longitude, while the longitudinal trend of the proportions of Vietnam （or Indo-Chinese Peninsula） to China （or SW. China） is on the contrary. The primary diffuse direction of Trop. Asia is from south to north, and the secondary from west to east. The flora composition of Southeast Yunnan is different from that of Southern and Southwest Yunnan. Though the Tanaka line may strictly restrict overall distribution patterns of Trop. Asia in Yunnan, its restriction may depend on Trop. Asia＇s subtypes. Thus, the investigations on subtypes＇ level may help us understand its underlying mechanisms more comprehensively and profoundly.