What shape is a tree? For most people, it’s like a lollipop or a feather duster: a single trunk topped by a green bunch of branches and leaves. “Not all trees are like that,” said Sharon Yiesla, plant ...

Scientists have mapped microbe populations in human guts, deep-sea ecosystems and even clouds. Yet the microbial communities inside tree trunks have remained largely unseen until now. For a recent ...