North American Trees Dying Twice as Fast

sugar-pine-dying-from-bark-beetle-attack-in-yosemite-national-parkimage-courtesy-of-jerry-franklinBy Stephen Leahy

UXBRIDGE, Canada, Jan 22 (IPS)

Our trees are dying. Throughout the western United States, cherished and protected forests are dying twice as fast as they did 20 years ago because of climate change, researchers reported Thursday in the journal Science.

Fire did not kill these trees, nor did some massive insect outbreak. The trees in this wide-ranging study were “undisturbed stands of old growth forests”, said Jerry Franklin, a professor of forest resources at the University of Washington and one of 11 co-authors of the report.

“The data in this study is from our most stable, resilient stands of trees,” Franklin told IPS.

What this means is that the United States’ best forests are getting thinner.

It is like a town where the birth rate is stable but the mortality rate for all ages doubled over the past two decades. “If that was happening in your hometown you’d become very concerned,” said Nate Stephenson, an ecologist with the U.S. Geological Survey (USGS).

This dramatic increase of in tree mortality applies to all kinds, sizes, ages and locations of trees. In the Pacific Northwest and southern British Columbia, the rate of tree death in older coniferous forests doubled in 17 years. In California, doubling mortality rates took a little longer at 25 years. For interior states it took 29 years. Continue reading