At the upper timberline the trees begin to become twisted and deformed.

行线，和雪线一样，在热最高，在极地最低。从极地地区的海平面到干燥的亚热地区的海拔4 500米处以及潮湿的热地区海拔3 500米至4 500米处都有行线。线内通常是常绿，它们和处于行线处极端恶劣环境中生长的落叶木相比，具有一定的优势。然而，在部分地区也有由落叶阔叶林组成的线。例如，在喜马拉雅的部分地区，桦就在线。

It is called an ever-green tree; for as long as one old brown leaf drops off, a fresh green one grows in its place.

青是一种" 常绿" ，因为只要青的一片叶子变成了棕色，落了下来，在原来的地方，就会长出一片新的绿叶！

Annual and perennial plants, deciduous and evergreen trees, plants inhabiting different stations and fitted for extremely different climates, can often be crossed with ease.

一年生和多年生植物、 落叶和常绿、栖息在不同地点并适应截然不同气候的植物通常可以轻松杂交。

On the other end of the spectrum are plants that don't shed their leaves — for example, the pines, spruces, cedars and firs that make up the conifers, or evergreens.

不会落叶的植物包括松、云杉、雪松和冷杉等针叶或常绿。

This continent is dominated by a single family, Eucalyptus, which is evergreen, regardless of the substantial climatic variations found there, and leads to forests unlike any other in character.

这片大陆主要盛产桉科，无论那里的气候变化如何，桉始终是常绿，并且形成了与其他森林不同的特征。