澜沧江流域(云南段)种子植物区系成分的纬度分布格局  

Latitudinal patterns of floristic elements of seed plants in Lancang river in Yunnan,southwest China

作　　者：冯建孟[1] 毛光权[1] 李珍贵[1] 

机构地区：[1]大理学院生命科学与化学学院,云南大理671000

出　　处：《生态环境学报》2012年第12期1928-1934,共7页Ecology and Environmental Sciences

基　　金：云南省自然科学基金项目(2010CD077);大理学院科研启动基金项目(KY431040)

摘　　要：对植物区系起源、分布和迁移过程的分析对我们更好地理解植被的发生、演化和分布具有重要意义。利用大尺度的植物区系分布信息,结合地理信息系统(GIS)空间分析和二元相关性统计分析,探讨了澜沧江流域(云南段)种子植物区系成分的纬度分布格局及河谷的"通道效应"。结果表明,研究区域内热带植物区系成分占主导地位,而温带区系所占比重则仅为1/3左右,故表现出明显的热带区系性质。其中,比较重要的区系成分主要包括热带亚洲分布(T7)(21.2%)、泛热带分布(T2)(16.5%)和北温带分布(T8)(11.7%)等。区系过渡性随着纬度的升高,从南到北呈先增强后减弱的单峰分布格局,纬度26o N左右出现峰值。这可能与其地处低纬度地区、紧邻古热带植物区的区系地理位置和南-北方向上海拔梯度有关。温带区系成分所占比重随着纬度的升高呈明显递增趋势,而热带区系成分所占比重则呈明显递减趋势,这与不同区系成分的生态特性和纬度梯度上的热量递减格局是一致的,同时也可能与澜沧江河谷在植物区系迁移过程中所发挥的"通道效应"有关。中国特有分布成分所占比重与表征地形复杂度的海拔高差之间存在明显的正相关关系,这可能意味着特有植物类群的形成和演化与地理隔离机制有关。Floristic origin, distribution and migration may have important implications in understanding the origin and formation and evolution of local vegetation. In this study, we examined the latitudinal patterns of floristic elements of seed plants in Lancang river in Yunnan and the rivers corridor effects through spatial analysis and Pearson correlation analysis. Our results showed that tropical elements predominated over others, and the proportion of temperate elements was only around one third, suggesting strong topical characters of the flora in the studied area. The important elements mostly included elements from Tropical Asia （21.2%）, Pantropic regions （16.5%） and North temperate regions （11.7%）. With the increase of latitude, floristic transitions increased and then decreased, and reached its peak around 26°N latitude. It was consistent to its biogeographic location adjacent to ancient tropical regions and topographic patterns. With the increase of latitude, an increasing trend can be observed on the proportions of temperate elements, while those of tropical elements showed contrary patterns, which may be strongly correlated with their different ecological characters, decreasing trend of energy on the latitudinal gradient and the river＇s corridor effects. There were strong correlations between the proportions of the elements endemic to China and altitudinal range, which may imply that the formation of endemic plants may strongly correlate with local geographic isolations.

关 键 词：植物区系 纬度格局 通道效应 澜沧江流域 云南 

分 类 号：Q948[生物学—植物学]