Healthy trees are also better able to fend off insects.

健康的树种防御虫害的能力更加强大。

Even healthy trees can be infected at any time.

即使是健康的树木也可能随时受到感染。

Large healthy trees could possibly survive for several decades without photosynthesis, due to slow metabolism and substantial sugar stores.

由于新陈代谢缓慢和大量的糖分储存，大型健康树木可能在没有光合作用的情况下存活数十年。