A study co-written by a West Virginia University biologist concludes that poison ivy will become more widespread and toxic within the century, possibly impacting not only the health of many Americans but the global ecosystem.


Richard Thomas, an associate professor of biology in WVU s Eberly College of Arts and Sciences, co-authored a study on the effects of elevated carbon dioxide, primarily caused by burning fossil fuels, on poison ivy abundance, growth and potency.


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


The study compared the growth and potency of poison ivy using levels of carbon dioxide commonly found in the air now and levels projected in the year 2050.


The results showed poison ivy growing with the elevated carbon dioxide levels had 153 percent more urushiol �€the active component in poison ivy �€and had grown 150 percent larger, or twice the size of the poison ivys growth at current carbon dioxide levels.


The six-year study, �€?Biomass and toxicity responses of poison ivy (Toxicodendron radicans) to elevated atmospheric CO2 ,�€? was published 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 near Chapel Hill, N.C.


�€?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,�€? Thomas explained.


Thomas obtained his doctorate at ClemsonUniversity working on plant responses to changes in atmospheric carbon dioxide and climate change. He then went to DukeUniversity to work with Boyd Strain, one of the pioneers in this type of research. Together, they worked to develop the FACE experiment.


This experiment was the first to manipulate an intact forest ecosystem, he noted.


�€?It builds on many greenhouse and chamber experiments where individual plants were examined under different conditions of climate change,�€? Thomas said. �€?Now there is a whole network of FACE experiments worldwide that examines many types of ecosystems.�€?


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


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 the study go beyond the human allergic response to poison ivy and are pertinent to various global ecosystems as well, Thomas said.


�€?Many policy-makers hope that forest trees will take up much of the carbon added to the atmosphere from burning fossil fuels and improve climate change by absorbing this greenhouse gas,�€? he said. �€?This research suggests that forests will take up some but probably not enough to mitigate climate change.


�€?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.�€?