The Botanical Advantage to Climate Change

5 12 2009

According to a new research article published in the journal, Global Change Biology, researchers from the University of Wisconsin – Madison and the University of Minnesota – Morris conclude that evidence extracted from local Aspen and Birch trees suggest that the impact of inflated amounts of carbon dioxide in the atmosphere has increased the trees’ growth rates. This comes after researchers sampled the rings within the trees and compared it’s growth rates with the increase in carbon dioxide. The two seem to be in near perfect symmetry with one another. All plant-life absorb carbon from the atmosphere and convert it to energy for the plant to survive – a process known as photosynthesis.

A strand of Aspen.

“Trees are already responding to a relatively nominal increase in atmospheric carbon dioxide over the past 50 years,” says Rick Lindroth, a UW-Madison professor of ecology and an expert on plant responses to climate change.

It seems the two species of North American tree have taken the increase in carbon and in itself increased it’s rate of growth. Aspen and Birch trees, particularly in the American Midwest, are considered “foundation species”. These particular species impact every other plant around them. The concern that is impacting the researchers’ interests as well as the rest of the science world – is what effect will the increased growth of these species have on their symbiosis with other plants. Some plants which grow slowly may be overtaken and consumed by the rapid growth of these trees.

Ecological impacts involving the vitae of plant-life and the effects the plants themselves have on each other and their locale is a big question. Ecology is an ever-changing field and it’s very hard to predict what impacts factor A will have on factor B and vice versa.

“We can’t forecast ecological change. It’s a complicated business,” explains Waller, a UW-Madison professor of botany. “For all we know, this could have very serious effects on slower growing plants and their ability to persist.”

To the surprise to many, the growth rate of these particular species has increased phenomenally – as much as 50% faster growth than 100 years ago. The next question is, how much more carbon can the plants absorb? The plants can only handle so much carbon and can only grow to a certain point.

“Forests will continue to be important to soak up anthropogenic carbon dioxide,” says Waller. “But we can’t conclude that aspen forests are going to soak up excess carbon dioxide. This is going to plateau.”

“Aspens are already doing their best to mitigate our inputs,” agrees Cole. “The existing trees are going to max out in a couple of decades.”

The new study was funded by the National Science Foundation and the University of Minnesota – Morris.