At the upper timberline the trees begin tobecome twisted and deformed .
在上行的树带界限中,一些数目开始扭曲变形。
There are some areas , however , where broadleaf deciduous trees form the timberline .
然而在某些区域,阔叶落叶树木组成了树带界限。
Timberline trees are normally evergreens , suggesting that these have some advantage over deciduous trees ( those that lose their leaves ) in the extreme environments of the upper timberline .