You may have noticed poison ivy spreading more in your backyard lately this summer, you might not be imagining it. Some studies reveal the three-leafed weed benefits from the effects of climate change.
Poison ivy is considered native to Ohio and much of North America. Touching or brushing against the plant, can result in painful swelling, itching, blisters or a rash for many people.
If you live in a region where there’s lots of poison ivy, you might notice it has bigger leaves and more vines. An early 2000’s Duke University study reveals climate change plays a role in that.
Marcus Nagle, a horticulture professor at Central State University, said it’s mostly because of higher carbon dioxide levels in the atmosphere.
“The increasing CO2 concentration in the Earth's atmosphere actually stimulates or promotes plant growth,” Nagle said. “That being said, the secondary effect of the increased CO2 is the increased temperatures that we might expect, and that will cause our springs and falls to be warmer.”
In the six-year study, scientists raised the ambient levels of carbon dioxide in a section of a forest. They found with higher levels of CO2 the plant increases its photosynthesis, it uses water more efficiently and it grows faster and bigger. In addition, poison ivy prefers warmer weather so the plant is likely to keep growing well into the fall until the first frost of the season.
Nagle said some plant species, not just poison ivy, can adapt and will respond similarly to higher carbon dioxide levels. Though not all plants will respond the same, such as more sensitive Ohio native species.
“Those effects of climate change are not going to be beneficial for all plants,” Nagle said. “And in addition to the change in climate and the potential negative effects on some of our other native species, you're [likely going to] see the increased prevalence of disease and pests.”
The Duke University study suggests higher CO2 levels might also make poison ivy more poisonous, which means a more intense rash.
Nagle said there’s already plenty of studies on the impact of climate and food crops, though he would like to see more studies on how forests are changing as the climate warms.
Alejandro Figueroa is a corps member with Report for America, a national service program that places journalists into local newsrooms.
