Increasing Tree Mortality in a Warming World

A mix of factors is contributing to an increasing mortality rate of trees in the moist tropics, where trees in some areas are dying at about twice the rate that they were 35 years ago, according to a far-reaching study examining tree health in the tropical zone that spans South America to Africa to Southeast Asia.

And scientists believe the trend will continue.

"No matter how you look at it, trees in the moist tropics will likely die at elevated rates through the end of this century relative to their mortality rates in the past," said Nate McDowell of the Department of Energy's Pacific Northwest National Laboratory, who is lead author of the study published Feb. 16 in the journal New Phytologist.

"There is a host of factors that appear to be driving mortality, and the likelihood of those factors occurring is increasing," added McDowell, who headed the team of scientists from more than two dozen institutions across the globe who were involved in the study.