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  • SciGirls

SciGirls | Temperate Rainforest | PBS

Duration: 07:06
Program: SciGirls

We're Emma and Gracie, and we live in Ketchikan, Alaska, where it rains 25 feet a year! All that water helps trees and other plants grow like crazy. That’s why the Tongass National Forest grows so well here. Some days when it’s raining, and we can’t get out to enjoy nature, we go to the next best place—the Southeast Alaska Discovery Center. They have a cool exhibit that brings the forest inside. The exhibit got us thinking about tree growth. Our question: How long would it take for a new tree to grow as big as an old growth tree?

We visited three areas of the forest: thinned, non-thinned, and old growth. In each location, we collected data from 2 small and 2 large trees. We measured tree diameters and took tree ring samples from a total of 12 trees. Then we counted rings and estimated the trees’ ages. We figured the growth rate of each tree by dividing diameter by age.

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Post Date: June 2, 2011