Research links tree die-offs to climate change

John Upton in the Bay Citizen (San Francisco): Fungus-related plant diseases are wiping out forests across the world – and new research indicates a similar phenomenon emerged as a result of radical climate change some 250 million years ago. That in turn suggests that scourges such as sudden oak death, Dutch elm disease, and the collapse of eucalyptus stands in Australia could be linked to contemporary climate change.

These and other diseases attacking the world’s forests are caused by fungus, or by close relatives of fungus, and some scientists believe the fungi are seizing on tree weakness triggered by climate change and pollution. In a new paper published online Friday by the science journal Geology, UC Berkeley plant biologist Cindy Looy and fellow researchers based in England and the Netherlands argue that soil fungus played a major role in the disappearance of forests millions of years ago.

The prehistoric trees might have been weakened by rapid changes in the earth's climate at the end of the what's known as the Permian period, making them more vulnerable to fungus attacks, according to Looy. “The plants that were still around were not doing well, and if plants are not doing well they’re much easier to attack by fungi,” Looy said. “Their defense system is down.”

Looy said it's impossible to rule out the possibility that future climate change will trigger similar devastation in forests across the world. Such an event, though, would be caused only by "really, really big" changes in the earth's climate....

A dead tree shot by Luis2492LuisArgenal, Wikimedia Commons, under the Creative Commons Attribution 3.0 Unported license