1·Hundreds of tree species face extinction.
很多树种濒临灭绝。
—— 《柯林斯英汉双解大词典》
2·Hundreds of tree species face extinction because of deforestation.
由于森林砍伐，很多树种濒临灭绝。
3·Only a small number of tree species have the genetic capacity to grow really big.
只有少数树种拥有长到很大的遗传能力。
4·The organic litter of another tree species might add less acid but more of something else.
另一种树种的有机凋落物可能不会添加这么多酸，但会添加较多的其他物质。
5·The aim is to reverse the decline in the number of tree species or at least to preserve the "genetic material" of all of them.
其目的是扭转树种数量下降的趋势，或至少保存所有树种的“遗传物质”。
6·Pests often target specific tree species and, if they become established, they usually remain as permanent components of the ecosystem.
害虫通常以特定的树种为目标，一旦形成，它们通常会成为生态系统的永久组成部分。
7·Shifts in forest species composition ramify through the ecosystem in many ways because tree species have different, often unique properties.
由于树种具有不同的、往往是独特的特性，森林物种组成的变化以多种方式影响着生态系统。
8·Long-term effects are primarily mediated by changes in tree species composition and the consequent alterations of forest structure, productivity, and nutrient uptake.
长期影响主要是由树种组成的变化以及随之而来的森林结构、生产力和养分吸收的变化所导致的。
9·China has the world's most ancient tree species — metasequoia.
中国有世界最古老的树种——水杉。
—— 《新英汉大辞典》
10·What's more, many tree species are also disappearing.
更重要的是，许多树的种类也即将濒临灭绝。