COLUMBUS (TDB) -- Photos of some outsized vines that look like plant kingdom anacondas accompany an Ohio State University research study which hints an increase in greenhouse gases could eventually strangle the Earth's forests.
The vines thrive on elevated levels of carbon dioxide, and they are flourishing at the expense of forests, where young trees can't seem to catch a toehold. All of this could be a signal of global warming, or climate change.
Ohio State's scientists have been studying forestlands in South Carolina, where the number of vines has increased by 10-fold over the past 20 years. The vines climb and wrap around tree trunks with tendrils that bite onto the bark. Their grip is deadly.
Bruce Allen, lead author of the study from OSU's school of environment and natural resources, says:
"Collectively, we're talking about an increase of more than 500 vine stems in 27 acres of forest area that we studied. And all of the growth is within the last 10 to 20 years. Old photographs from the sides indicate there may have been fewer vines historically. There are now so many vines that they're starting to change the makeup of the forest. It appears that as the number of vines increase, the density of small trees decreases at a fairly uniform rate."
Other studies have shown CO2 helps poison ivy, and that vines benefit from the gas more than other plants. The researches didn't say the cause is global warning, but said the increase in CO2 is a "possible mechanism" for the changes they have observed.
Interestingly, they said Mother Nature helps the trees with hurricanes and windstorms. They knock holes in the forest canopy, and the sunlight kills the vines, allowing the trees to come back.
So here's a possibility: Global warming causes stronger storms (as many meteorologists have theorized) that wipe out all the vines that have taken hold because of global warming. The OSU research report is available here.
As the author of this paper, I would take a somewhat different approach to the impact of disturbance on vines and trees. In an earlier paper I found that the number of vines on a tree influenced its chance of dying in hurricane winds. Yes, when the tree blows over or snaps, the lianas die with it. In the Congaree National Park, lianas responded to higher levels of disturbance, nearly doubling with in 16 years now (and still increasing). Any negative impact was short lived. I would expect that high levels and more frequent distrubance will favor vines in the long run.
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