The length of the growing season may be lengthening due to rising carbon dioxide levels in the atmosphere. The growing season has grown by two weeks in the United States and about one week in Europe over that last 100 years. Ecologist Heidi Steltzer says that it is not due to rising temperatures, but to the CO2 levels themselves. Heidi and her colleagues exposed plots of Wyoming grassland to CO2 or heat. The data shows that the CO2 lengthened the season by 2 weeks while the heat grew by 1 week. The ecologists agree that CO2 also conserves water in agriculture by allowing leaves to close their stomata. Richard Nordby has repeated these results on gum forests of Tennessee.
NOS Themes:
Science is collaberative - This experiment was a team effort by Heidi Stelzer and her team.
Importance of repeatability - Results were repeated in Tennessee.
Christopher, this information really surprised me. I wonder if the rising amount of CO2 has any other effects on the environment. With the extended growing season, I wonder how much the farmers crops will increase. I imagine that the changes in the growing season also throw off their timing for the crops. I did some further research and was surprised to find that scientists believe that the longer growing season might causes flowers, such as roses, to fall out of sync with the bee pollination.
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