Forest Service Scientists, High in the Trees

By Elizabeth Arnold

Published July 6, 2005 at 12:00 AM EDT

The Wind River Canopy Crane towers 25 stories above the forest floor.

Inside the goldola at the end of the crane arm -- a long way down. At the upper right corner is a glimpse of the base of the crane.

From left, Elizabeth Arnold, University of Washington ecologist David Shaw and U.S. Forest Service researcher Rick Meinzer, high above the forest in southwest Washington State.

President Theodore Roosevelt established the U.S. Forest Service 100 years ago this month. Through a century of natural and social change, the agency has managed more than a billion acres of land, from the cypress swamps of the deep south to the rain forests of the Pacific Northwest.

And while balancing economic and recreational needs have dominated its history, scientific research has become a larger part of the agency's mission. In the first of two National Geographic Radio Expeditions, Elizabeth Arnold gets a very different view of one forest, from high above the trees.

A construction crane stands 25 stories tall in the Wind River Experimental Forest in southwest Washington state. From that vantage point, researchers can get a bird's-eye view of everything from evidence of climate change to caterpillars.

Scientists have come to Wind River since 1909, when five acres of forest were cleared and seedlings planted. Soon that plot grew to 180 acres, and research over the next eight decades focused on growth, yield and mortality of Douglas fir for the agency's tree plantations.

By the 1970s, the focus broadened to the composition and wildlife of the last remaining old-growth forests. And in 1994, the forest service joined with the University of Washington to erect the canopy crane as a tool to study the tops of these old trees, some of the tallest in the world.

That unlikely construction crane has become a huge research tool. Scientists in the gondola at the end of the crane arm can swing in a 550-foot circle, giving access to nearly six acres of old growth trees from bottom to top.

For those scientists, the canopy is where the action is. It's where most of the budding, branching and photosynthesis occurs. With the data they collect here, they can get a bigger picture of tree physiology and growth, how trees absorb carbon dioxide, use water, and their relationships with lichen, fungi, birds and insects.

More than a dozen projects at the research forest are focused on climate change. And just as doctors can't diagnose human health by looking at the lower two-thirds of a patient, researchers need to examine the entire tree, especially when it comes to understanding the carbon cycle.