But the most formidable challenger is the humble downy birch.

但最强大的挑战者是不起眼的绒毛桦树。

The downy birch detected the current warming trend much earlier than most scientists.

绒毛桦树比大多数科学家更早地发现了当前的变暖趋势。

The downy birch dictates the terms of what can grow, survive and move in the areas in which it takes hold.

绒毛桦树决定了在它所占据的地区什么可以生长、生存和移动的条件。

Intermingled with the pines were shorter, ragged-looking trees with lumpy trunks, wizened branches and fine twigs like gnarled fingers: Betula pubescens, downy birch.

与松树混在一起的是矮小、参差不齐的树，树干粗糙，树枝干枯，细枝像多节的手指：白桦、绒毛桦树。