Poison ivy’s time of greatness

Many people are making a poisoned lemonade from the lemons of climate change. They’re saying “Bring it on” with the expectation of agricultural improvements. That’s extremely short-sided and somewhat misguided, but here’s some news from the natural world of plants that goes along with the story.

U.S.D.A. researcher Lewis Ziska explains the reason for the abundance of poison ivy – that along with a more virulent oil. It’s the increase of carbon in the atmosphere, he says:

carbon dioxide, as everyone knows, is a basic greenhouse gas, but it’s also plant food. And plants take that carbon, and they convert it into sugars and carbohydrates and so forth.

But not all plants respond the same way to that resource, and we think that vines, particularly vines like poison ivy or kudzu or other noxious weeds, seem to show a much stronger response to the change in CO2 than other plant species. So on average, the poison ivy plant of, say, 1901, can grow up to 50 to 60 percent larger as of 2010 just from the change in CO2 alone, all other things being equal.

And as a result of that change, we see not only more growth but also a more virulent form of the oil within poison ivy. The oil is called urushiol, and it’s that oil that causes that causes that rash to occur on your skin when you come into contact with it.