Treating them as alien species.

把它们当作外来物种对待。

What can be done about invasive alien species?

怎样处理外来入侵的有害物种?

This paper discusses and identifies the concepts of alien species and alien invasive species;

讨论并界定了外来种和外来入侵种的概念；

The number one threat in the Garden Route National Park for biodiversity at this point is alien species, alien plant species.

就花园路国家公园的生物多样性而言，它面临的头号威胁就是外来物种，外来植物。

I may have just betrayed my people to a ruthless alien species.

我也许刚刚为了一个残忍的外星物种背叛了我的人民。

Invasive alien species have caused to severe damage to ecosystem function.

外来入侵物种已对我国生态系统功能造成严重破坏。

These countries may not yet have developed the policies to deal with alien species, but they have an opportunity to learn those lessons before more alien species are introduced.

这些国家也许还未执行处理外来物种的政策，但是在更多的物种引进前，他们有机会学习那些教训。

Genetic diversity is hypothesized to affect the invasiveness of alien species.

遗传多样性被认为是影响外来种入侵成功的重要因素之一。

Here are my top five reasons why an intelligent alien species will never invade our planet

以下是五个为何外星高级生物不会入侵地球的主要原因

Kent think he knows why: Perhaps only the wiliest of alien species survive the interstellar version of evolution.

肯特认为他找到了答案：或许只有最为狡诈的外星种族才能挺过从大陆文明向太空文明过渡的挑战。