中文摘要：

作为在 forested 山斜坡和高山的草地 / 灌木之间的一条突出的生态的边界，高山的 treeline 在高度的分发是高度复杂的并且对温暖气候敏感。大努力被作了探索他们决定这些模式超过 100 年的分发模式和生态的机制，并且相当很多地理并且 ecophysiological 模型与纬度被开发了到相互关联 treeline 高度或纬度联系了温度。在全球规模上，然而，所有这些模型有大困难精确地由于 treeline 地点条件的极端差异预言 treeline 举起。主要原因之一是集体举起效果(MEE ) 没全球性被确定并且尽管它被观察了，它在欧亚的大陆和北半球的 treeline 举起上的效果认出了，与全球 treeline 举起联系了。在这研究，我们从文学在整个世界收集了并且编，并且探索了 MEE 怎么由与intra山脉底举起开发一个第三的线性回归模型影响全球 treeline 举起 594 个 treeline 地点的一个总数( IMBE ， MEE 的一个代理)，纬度和陆性率同样独立的变量。结果一起显示了那 IMBE，纬度和陆性率能解释 92% 全球 treeline 举起可变性，并且那 IMBE 贡献大多数(52.2%) ，纬度第二(40%) 并且陆性率最少(7.8%) 到全球 treelines 的高度的分发。在北半球，三因素贡献分别地等于 50.4% ， 45.9% 和 3.7% ；在南方半球，他们的贡献分别地是 38.3% ， 53% ，和 8.7% 。这显示那 MEE，几乎宏地形的加热效果，实际上是为越过地球，和那纬度的 treelines 的高度的分发的最重要的因素相对为在南部的半球的 treeline 举起更重要可能由于在那里的更少宏地形。

英文摘要：

Alpine treeline, as a prominent ecological boundary between forested mountain slopes and alpine meadow/shrub, is highly complex in altitudinal distribution and sensitive to warming climate. Great efforts have been made to explore their distribution patterns and ecological mechanisms that determine these patterns for more than 100 years, and quite a number of geographical and ecophysiological models have been developed to correlate treeline altitude with latitude or a latitude related temperature. However,on a global scale, all of these models have great difficulties to accurately predict treeline elevation due to the extreme diversity of treeline site conditions.One of the major reasons is that ＂mass elevation effect＂（MEE） has not been quantified globally and related with global treeline elevations although it has been observed and its effect on treeline elevations in the Eurasian continent and Northern Hemisphere recognized. In this study, we collected and compiled a total of 594 treeline sites all over the world from literatures, and explored how MEE affects globaltreeline elevation by developing a ternary linear regression model with intra-mountain base elevation（IMBE, as a proxy of MEE）, latitude and continentality as independent variables. The results indicated that IMBE, latitude and continentality together could explain 92% of global treeline elevation variability, and that IMBE contributes the most（52.2%）, latitude the second（40%） and continentality the least（7.8%） to the altitudinal distribution of global treelines. In the Northern Hemisphere, the three factors’ contributions amount to 50.4%, 45.9% and 3.7% respectively; in the south hemisphere, their contributions are 38.3%, 53%, and 8.7%, respectively. This indicates that MEE, virtually the heating effect of macro-landforms, is actually the most significant factor for the altitudinal distribution of treelines across the globe, and that latitude is relatively more significant for treeline elevation in the Southern Hemisphere pr