Experts warn that global warming and a rise in carbon dioxide levels could dramatically increase the spread of plants such as poison ivy, while altering the growing season and coverage of other plants species.
Poison ivy is an example of a species benefiting from rising carbon dioxide (CO2) levels and warmer temperatures, which are both ideal for maximizing its growth potential.
Since the 1960s, poison ivy growth and its potency have doubled. Researchers at the U.S. Department of Agriculture warn that these figures could double again, after CO2 hits the 560 ppm level.
It’s no surprise that poison ivy is dangerous to humans. A billionth of a gram of urushiol, the substance in poison ivy that’s toxic to humans, is enough to cause an uncomfortable reaction to the human body. Except for primates, animals in general experience no negative effects from the plant. In fact, many animals find poison ivy somewhat of a delicacy.
According to ESSIC Professor Dr. Raghu Murtugudde, poison ivy growth is increasing because high levels of CO2 give the plant a competitive edge over other species, which don’t the plant’s innate ability to self-adjust how they photosynthesize.
Murtugudde explained that when dinosaurs roamed the earth, CO2 levels were at three times the levels they are currently. As the levels dropped, plant species capable of adjusting to the lower CO2 levels and changing temperatures became dominant. Poison ivy is an example of this earlier plant evolutionary cycle repeating itself, as it begins to replace other plant species that can’t adapt to higher CO2 environments.
Increasing levels of poison ivy are not the only plant implication associated with rising temperatures however. Increasing temperatures are also causing some plants to alter their growing season – a change that ESSIC Research Assistant Professor Melissa Kenney says can only be attributed by climate change.
Kenney stated that some plants are beginning to have earlier and longer growing seasons to accommodate changes in temperature. These new growing season trends will alter what humans are able to produce in certain areas.
Kenney’s comments echoed the findings of ESSIC Director and Professor Antonio Busalacchi, who has received considerable media and research attention this summer, with a study projecting how the world’s major wine-growing regions could be altered as a result of warming temperatures.