Biology Professor Co-Authors Poison Ivy Study

Morgantown, WV, June 14, 2006:  In this season of outdoor activities, a timely study was released today showing how poison ivy will become more widespread and toxic within the century.

Dr. Richard Thomas, Professor of Biology in the Eberly College of Arts and Sciences at West Virginia University, co-authored a study on the effects of elevated CO2, primarily caused by burning fossil fuels, on poison ivy abundance, growth and potency. This 6-year study, “Biomass and toxicity responses of poison ivy (Toxicodendron radicans) to elevated atmospheric CO2,” was published on June 13 in Proceedings of the National Academy of Science. The results were gathered from the experimental Duke University Free-Air CO2 Enrichment (FACE) forest, located near Chapel Hill, NC.

“With this technology, carbon dioxide is released through large pipes in a ring of towers in the forest, monitored and controlled by computers to be the approximate concentration that is expected in the year 2050,” said Dr. Thomas. He explained that this experiment was the first to manipulate an intact forest ecosystem.

“It builds on many greenhouse and chamber experiments where individual plants were examined under different conditions of climate change,” he continued. “Now there is a whole network of FACE experiments worldwide that examines many types of ecosystems.”

Dr. Thomas asserted that the main objective of the FACE research is to understand the role of forest in the global carbon cycle.

According to the study, approximately 80% of humans develop Toxicodendron dermatitis. This is the human immune system’s reaction to urushiol, the active component in poison ivy. Annually, poison ivy causes more than 350,000 reported cases of this commonly known rash.

“Our research on poison ivy is one of the first that links increasing atmospheric carbon dioxide with a change in human health, but it also indicates a potentially strong negative effect on forest health,” he said. “We found that poison ivy responded to elevated CO2 to a greater degree than almost any other plant species in the forest, including the trees.”

The findings indicated that under levels of atmospheric CO2 predicted for the year 2050, poison ivy may grow larger and become more noxious than it is currently measured. The study compared poison ivy at CO2 levels of 2050 to poison ivy at the current CO2 levels. By 2004, the poison ivy with the elevated-CO2 had an increased concentration of 153% more urushiol and had grown 150% larger, or twice the size of the poison ivy’s growth at current CO2 levels.

The study reports “the increased abundance of woody vines [such as poison ivy] in old-growth and fragmented forests is reducing tree regeneration and increasing tree mortality in tropical and temperate regions.” Therefore, the implications of this study go beyond the human allergic response to poison ivy; they are pertinent to various global ecosystems, as well.

“Many policy makers hope that forest trees will take up much of the carbon added to the atmosphere from burning fossil fuels and thus, ameliorate climate change by absorbing this greenhouse gas. This research suggests that forest will take up some but probably not enough to mitigate climate change,” he stated. “Vines, by their very nature, can severely affect forest structure and function because they use other plants as their support and can grow up through the canopy and choke out other plants,” he added. “If poison ivy or other vines gain an advantage over other plants, the world will certainly get weedier.”

Dr. Thomas received his PhD at Clemson University working on plant responses to changes in atmospheric carbon dioxide and climate change. After earning his PhD, he went to Duke University to work with one of the pioneers in this type of research, Dr. Boyd Strain, where he helped to develop the FACE experiment. Currently, he is a member of the WVU faculty where he provides research and teaching experience.

“The Department of Biology at WVU has a small, but very strong, group of faculty whose research is focused on ecological issues, including global environmental change,” Dr. Thomas reflected. “This provides a very supportive atmosphere to conduct my research and helps attract excellent graduate students.” For more information contact Dr. Richard Thomas at rthomas@wvu.edu.

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