Research news: Warming cuts trees' life in half

The News:
Report: Warming cuts trees' life in half
The death rate of woods in the West may also contribute to less carbon being trapped.
By Jennifer BrownThe Denver Post
Posted: 01/23/2009 12:30:00 AM MST
Updated: 01/23/2009 12:57:29 AM MST

The life span of trees in the western United States has been cut in half, and the likely cause is climate change, according to the most extensive research yet on the life span of pines, firs and hemlocks.
The death rate of trees in Colorado, California and the Pacific Northwest has more than doubled since 1955 as warmer temperatures have led to less moisture and severe drought, according to a paper published today in the journal Science.
Researchers predict the average size and age of trees eventually will decrease by half, forests will become more sparse, and trees will store less carbon than they do now, which is bad news for the planet. Trees trap carbon dioxide, a major greenhouse gas linked to warming temperatures.
The study "introduces the possibility that western forests could become net sources of carbon dioxide to the atmosphere, further speeding up the pace of global warming," said Phillip van Mantgem, a U.S. Geological Survey ecologist and study co-author.
Scientists from the USGS and the University of Colorado at Boulder said they were able to isolate regional warming as the most likely cause of increased tree mortality. They excluded air pollution and changes in forest dynamics, such as woodlands becoming more dense.
Their findings suggest that otherwise healthy trees — undisturbed by logging, fire or massive pest outbreaks — are living only half as long as they once did. Read on...

The Research:
Read the research behind this story in the journal Science.