Ecologists are infecting trees with fungi to make them age prematurely

I am in a forest 35 kilometres west of London, meeting someone who is trying to make young trees old. “Old trees form hugely important habitats,” says Lynne Boddy, a mycologist at Cardiff University, UK. “But in Europe in general, including in Britain, we don’t have all that many now.” She is one of a handful of scientists around the world trying to do something about it.

Boddy takes me over to look at a gnarly oak, which is roughly 300 years old. …