An American tragedy: why are millions of trees dying across the country?

A quiet crisis playing out in US forests as huge numbers of trees succumb to drought, disease, insects and wildfire - much of it driven by climate changeJB Friday hacked at a rain-sodden tree with a small axe, splitting open a part of the trunk. The wood was riven with dark stripes, signs of a mysterious disease that has ravaged the US's only rainforests - and just one of the plagues that are devastating American forests across the west.Friday, a forest ecologist at the University of Hawaii, started getting calls from concerned landowners in Puna, which is on the eastern tip of Hawaii's big island, in 2010. Their seemingly ubiquitous ohi'a trees were dying at an astonishing rate. The leaves would turn yellow, then brown, over just a few weeks - a startling change for an evergreen tree. Continue reading...