我国水青冈属植物的地理分布格局及其与地形的关系

Distribution Patterns of Chinese Beech (Fagus L.) Species in Relation to Topography 

利用我国水青冈属（ＦａｇｕｓＬ．）植物的地理分布资料和１∶１００万地形图资料，利用Ｋｒｉｇｅ空间统计方法对我国分布较广的４种水青冈，即长柄水青冈（Ｆ．ｌｏｎｇｉｐｅｔｉｏｌａｔａＳｅｅｍ．ｅｔＤｉｅｌｓ）、亮叶水青冈（Ｆ．ｌｕｃｉｄａＲｅｈｄ．ｅｔＷｉｌｓ．）、米心水青冈（Ｆ．ｅｎｇｌｅｒｉａｎａＳｅｅｍ．）和巴山水青冈（Ｆ．ｂａｓｈａｎｉｃａＹａｎｇ）的空间分布格局及其与地形的关系进行了研究。结果表明，我国水青冈属植物显示出南北变化较小、东西变化显著，一些区域出现较周围地区较高或较低分布的“岛屿化”现象的空间分布格局。这与我国的地形特征以及水青冈的生态特性等有关。沿不同经向剖面，分析水青冈的分布高度与地形平均高度之间的关系显示，随地形高度的增加，水青冈分布上限的高度也逐渐增加，其趋势可用对数或直线拟合，但不同种对地形高度变化的反应存在差异。这些结果不仅从较大尺度上定量说明了我国水青冈分布高度的山体效应现象，也揭示了物种间山体效应的差异。这种差异可能与物种的生态适应性和生态幅度有关。

Distribution pattern and its correlation with macro_topography of four widely distributed Chinese beech (Fagus L.) species, F. longipetiolata Seem. et Diels, F. lucida Rehd. et Wils., F. engleriana Seem. and F. bashanica Yang, were studied using their literature_reviewed geographic distribution data and computer_digitized topographical map of China with a scale of 1∶1 000 000. As a result, distribution patterns of Chinese beech species are characterized by an unclear south_to_north change, a remarkable east_to_west difference, and an “island distribution phenomenon” in some regions where a higher or lower distribution occurs than in their neighbering areas. This is closely coupled with macro_topography in China. Along the longitudinal directions, altitude at the upper limits of the four species increases with increasing mean topographic altitude in accordance with a logarithmic or linear function, but various species show different responses to the relationship between the species distribution altitude and the topographic altitude. These findings identify “massenerhebung” in Chinese beech distributions, and clarify their differences among the species. The differences may be related to ecological adaptability and ecological range of the species.