Far beyond the Christmas tree farms, in forests and ravines, lie the woolly-barked nurse logs. At first glance they are simply fallen trees: the corpses of the woods. But now they live a second, ...

Mark Harmon crouches low next to log number 219: a moss-covered western hemlock tree trunk, five meters long, lying dead on the ground in the lush green woods. It’s marked by a thin aluminum tag. The ...