Kudzu Poses New Threat to Environment
A researcher at the University of Virginia says Kudzu poses a new threat to the environment that is worse than anyone ever thought. Charles Fishburne has more in this Science Matters report.
Kudzu has been called “the Vine that ate the South.” Ever since its introduction into this country in the late 19th century, to control erosion, it has threatened to choke surrounding vegetation, but a UVa professor says it soon may be choking people.
Lerdau: You go outside and your eyes burn a little bit and your lungs get a little tight.
Lerdau: That is ozone acting as an oxidant, an oxidizing compound on the mucous membranes in our lungs and in our eyes, and you can actually cause, in essence, chemical burns on those tissues and, even more seriously, it can act as a mutagen, changing our DNA and leading, in some cases, to cancer.
Lerdau is a professor of environmental sciences and biology at the University of Virginia, who has just concluded research on kudzu, which he says is increasing ozone levels wherever it is found, by producing isoprene and nitric oxide, which combine with nitrogen in the air to produce ozone. In such high quantities he says, it threatens to undo all we’ve accomplished by reducing auto emissions.
Lerdau: There is now federal legislation regulating what can come out of the tailpipes of automobiles. And this began with legislation in the 1970’s and has been refined over the years and has been incredibly successful at reducing the levels of nitric oxide in the air that are there due to human activities. And now what we see with the spread and advance of kudzu across the eastern U.S., we see the possibility to undo all that good work because now we have a source of nitric oxide coming from the soil itself.
Lerdau says his projections are troubling.
Lerdau: Our model predicts that we will see about a 35-40 percent increase in the number of days in which it is actually healthier to sit inside and watch TV than to go outside and exercise.
Southerners already know what a nuisance kudzu has been, but it is apparently on the move.
Lerdau: Now it is spreading even faster because the one thing that was able to limit kudzu’s spread was minimum winter temperatures. Kudzu is very susceptible to low temperatures in winter and winter temperatures have been rising throughout the eastern United States. And we are seeing kudzu spreading now up into New York and even a few populations in Massachusetts.
It has a rapid, uninhibited growth rate about three times that of trees and vegetation, and in over 100 years, we still haven’t figured out how to stop it.
Lerdau: We have not found the magic bullet to control kudzu – livestock, grazing, burning, herbicides have not been very successful with kudzu control. My understanding is that lifestock grazing is still the very best method we have.
But, he says, it’s not enough, and it is time for public policy to address an issue that could become a major public problem.
Lerdau: We’ve just learned, and this is the how the system should work, that when scientists make discoveries, it’s time then for policy makers to move and act on them, and I think what we have with our work on kudzu is one more reason, and a very important one, that we need to focus even more on controlling this very scary plant.
Manuel Lerdau’s study is published this week in the journal Proceedings of the National Academy of Sciences.
Charles Fishburne, WCVE News.