In every tree, a trillion tiny lives

Scientists have found that a single tree can be home to a trillion microbial cells

- ALEXA ROBLES-GIL

A FOREST IS a complex, dynamic ecosystem in which a rich array of living things, from old-growth trees to microscopic fungi, interact and depend on one another for survival. So is the inside of a tree, it turns out.

Earlier this month, a team of scientists published the most comprehensive study of the microbiomes living inside tree trunks. Their findings suggest that the woody tissues of trees contain a trillion microbial cells above and beyond actual tree cells: communities of bacteria and single-celled organisms called archaea that have specialized to different parts of the tree and even to individual tree species. The study's results, published in the journal Nature, reveal a vast and largely unexplored reservoir of microbial diversity.