Ancient trees’ gnarled, twisted shapes provide irreplaceable habitats

Earth’s oldest, knotted and scarred pine trees are a boon for forest life. 

These old mountain pines (Pinus uncinata) offer food and shelter for lichens and insects not just because they’re old, but also because of what’s allowed them to grow so old in the first place, researchers report February 5 in the Proceedings of the National Academy of Sciences. The