Thursday, March 25, 2010

Global Warming: Making Trees Grow Faster

By Katie Lukshis

A study has been done on trees in eastern America leading to conclusions that forests may be growing faster now than they were over 200 years ago. Some 55 plots of mixed hardwood forests on the western end of the Chesapeake Bay in Maryland have been the areas of study over a period of 22 years, and the documented growth proves they are growing faster now than at any time in the past 225 years- the age of the oldest trees in the study, conducted by scientists of the Smithsonian Environmental Research Center. These specific trees have been selected because they represent much of the trees found on the Eastern Seaboard.

Geoffrey Parker, a forest ecologist, has stated on the issue that “the increase in the rate of growth was unexpected and might be matched to the higher temperatures and longer growing seasons documented in the region…[or] may also be influenced by the significant increase in atmospheric carbon dioxide,”. A detailed census on the trees has been carried out on a regular basis since 1987 by Parker and his colleagues, in which trees and saplings with a diameter of more than 2 centimeters have been measured and monitored. With this information, they then calculated that the forest is producing an additional two tons of wood per acre per year, which would be the equivalent of a tree with a 2 feet diameter sprouting up in the space of a year. Included in this survey were trees at different stages of growth, all of which showed an increase in growth rates.

During this same time that the scientists were studying various forests, they also measured the concentration of carbon dioxide in the forest air and discovered it had risen by 12%. Average temperatures increased by three-tenths of a degree and the growing season had lengthened by 7.8 days. These contributing three factors have all played a role in the increase in tree growth rate , according to the study authors.

Global warming is an issue that has been an ongoing debate for quite some time now. These findings are so intriguing to scientists because trees are known to play an important role in counteracting global warming – they absorb and use carbon dioxide in their photosynthetic reactions. Parker believes that the trees showing faster growth rates are already “sopping up some of the extra carbon”.

The downside to this study is that scientists are unsure if this process could be sustained. Other factors vital to tree growth such as water availability and soil nutrients are limited, and may disappear faster if this trend keeps up.

For More Information:
Connor, Steve. "Global Warming Makes Trees Grow at Fastest Rate for 200 Years." Independent UK. Alternet, 3 Feb. 2010. Web.

Kaufman, Leslie. "Study Finds a Tree Growth Spurt." The New York Times. 1 Feb. 2010. Web.

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