Figs (Ficus SPP., Moraceae) are important fruit resources for many frugivores, particularly during the period when other fruits are scarce, and so be called "keystone species".

榕属植物为多种食果动物重要的食物资源，特别是在其他果实缺乏的季节，因此有关键物种之称。

youdao

The unified management of water resources in the Tarim River Basin is all along a keystone of water resources management in Xinjiang.

塔里木河流域水资源统一管理问题，一直是新疆水资源管理的重点。

youdao

The Keystone pipeline would contribute the similarly booming resources of Canada to America, more than a million barrels a day, more than is imported from Saudi Arabia or Venezuela.

FORBES: As The Economy Recesses, Obama's Global Warming Delusions Are Truly Cruel

We can create tens of thousands of new American jobs by encouraging the development of America's vast energy resources and supporting truly shovel-ready projects like the Keystone XL pipeline, which would create an estimated 20, 000 jobs, according to TransCanada, while boosting domestic energy production.

CNN: Obama, where is the recovery?