Global warming is making poison ivy worse
June 26, 2007
New research shows that climate change is making poison ivy more potent, according to an article in The Wall Street Journal.
Recent studies by Lewis Ziska, a plant physiologist for the U.S. Department of Agriculture, and colleagues suggest that higher levels of carbon dioxide are allowing the noxious plant to grow faster, produce larger leaves, and generate a more allergenic form of urushiol, the rash-inducing oil the plant uses to defend itself.
In the latest experiments where poison ivy plants were grown under different levels of carbon-dioxide exposure, Ziska found that “leaf size, stem length and weight and oil content of the plants raised at current carbon-dioxide levels were, on average, 50% to 75% higher than the plants under the 1950s conditions,” writes Tara Parker-Pope in her “Health Journal” column. “Not only did the higher CO2 level double the growth rate, but it made for hardier plants that recovered more quickly from the ravages of grazing animals.”
“Contact with poison ivy (Toxicodendron radicans) is one of the most widely-reported ailments at United States¿ poison centers,” states the USDA web site. “Approximately 80% of humans develop dermatitis upon exposure to the carbon-based active compound, urushiol.”
The study will be published later this year in the journal Weed Science.
Citation: Mohan, J.E., Ziska, L.H., Sicher Jr, R.C., George, K., Thomas, R.B., Schlesinger, W.H. 2006. Poison ivy grows larger and more poisonous at elevated atmospheric CO2. Proceedings of the National Academy of Sciences. 103(24):9086-9089.