The Trees Are Dying

In the American West trees are dying faster than before due to global warming.

More trees are dying in the West's forests as the region warms, a trend that could ultimately spell widespread change for mountain landscapes from the Sierra Nevada to the Rockies.

Scientists who examined decades of tree mortality data from research plots around the West found the death rate had risen as average temperatures in the region increased by more than 1 degree Fahrenheit.
"Tree death rates have more than doubled over the last few decades in old-growth forests across the Western United States," said U.S. Geological Survey scientist Phillip van Mantgem, coauthor of a paper published in today's issue of the journal Science and released Thursday.

The researchers found rising death rates across a wide variety of forest types, at different elevations, in trees of all sizes and among major species, including pine, fir and hemlock.

"Wherever we looked, mortality rates are increasing," said Nathan Stephenson, a study coauthor and USGS research ecologist.

The faster the trees die the less carbon is stored and the trees die faster. It is going to be an interesting couple of decades.