PURCHASE, N.Y. - Topics as large as the natural defenses against climate change are now being researched around the corner by a professor at Purchase College.
Assistant Professor of Environmental Studies at Purchase College Susan Letcher has teamed up with Deborah Clark of the University of Missouri-St. Louis to study the effects of the climate on rain forests. In recognition of their findings, the National Science Foundation awarded them a $441,524 grant over the next 60 months.
Their research has shown that as the climate grows hotter each year, trees in the La Selva, Costa Rica rain forest produce greater amounts of carbon dioxide. Their work has also shown that trees may be dying prematurely.
"With the recent elevated death rate of trees, it's especially important now for us to get a clearer look at the link between climate and tree mortality," Letcher said.
Deborah and David Clark launched a study of the rain forest in northeastern La Selva in 1983 with the goal of examining the coexistence of different rain forest tree species. But the course of their research soon changed, Letcher said.
By February 2012 the study will have accumulated 29 years of data on the effects of climate on tropical trees, making it the longest-term study of its kind worldwide. It is also the most specific study of its kind because it measures data on an annual basis, which Letcher points out is critical to detecting patterns within a limited time frame.
"Early in their research, the Clarks discovered that many different tree species were showing the same pattern of growth, experiencing good and bad years at the same time, and they realized it was linked to climate," Letcher said. "Good years for the trees tended to be cool, while bad years were warmer."
Letcher said that as heat weakened the trees, lianas, or tree-damaging plants similar to poison ivy, grapevine, or Virginia creeper became more abundant.
"Lianas do better in heat, drought, and high levels of carbon dioxide than the trees do," Letcher said. "They compete with trees. With more lianas, you have more trees falling and dying. This is not only bad for the trees. It's bad for the atmosphere as well."
Letcher cautioned that the study of rain forests is still a young discipline and that additional research is crucial to understand links between lianas, climate, and tree growth.
"The more we get the word out about how climate change is affecting tropical forests, the more we can motivate people to act," Letcher said.
Click here to sign up for Daily Voice's free daily emails and news alerts.