Forests nationwide are feeling the heat from increasing drought and climate change, according to a new study by scientists from 14 research institutions.
“Over the last two decades, warming temperatures and variable precipitation have increased the severity of forest droughts across much of the continental United States,” said James Clark, lead author of the study and an environmental scientist at Duke University. Clark and colleagues published their paper today in the journal Global Change Biology.
“While the effects have been most pronounced in the West, our analysis shows virtually that all U.S. forests are now experiencing change and are vulnerable to future declines,” Clark said.
It’s a tall order to predict what these forests will look like in 20 years, the researchers say. Drought-induced forest diebacks (the deaths of entire communities of trees known as stands), bark beetle infestations, and wildfires are already occurring on large scales across the West. Many models predict droughts are likely to become more severe, frequent and prolonged across much of the U.S.
Evidence is also mounting that climate is changing faster than tree populations can respond. As conditions become drier and warmer, many tree populations, especially those in Eastern forests, may not be able to expand into new, more favorable habitats, fast enough to keep up.
From the National Science Foundation: http://www.nsf.gov/news/news_summ.jsp?cntn_id=136815&org=NSF&from=news