Scientists In Trees

It’s the Wind River Canopy Crane and stands 285 feet or about 28 stories above the floor of the Gifford Pinchot National Forest. Scientists go nearly that high to take measurements and gather samples year round, weather permitting. It sits in a part of the national forest that has been designated since 1932 as an experimental forest. That means researchers have been using the area as a living lab, conducting research while also trying to keep the area in as close to its natural state as possible.

By using the crane, scientists can quickly and easily move from branch to branch. Ken Bible of the University of Washington is the crane’s site director. He says, “Climbing to the top of one of these old growth trees is dangerous, even on a good day, but then making it out to the end of the branch is suicidal. The canopy crane brings us back to these places safely.” In less than an hour researchers have visited, measured and photographed branches in a dozen different trees.

Without the crane, the same task might have taken days. Using the crane not only makes research easier for the scientists, but increases the amount of information they’re able to gather.

The crane is one of ten such research cranes. It’s the only one in North America and the only one erected in a temperate forest. “We wanted it in this region, says Jerry Franklin of the University of Washington, “particularly because these forests are extraordinary forests. They’re extraordinary in terms of their dimensions, their massiveness.” Using the crane the scientists can reach about 300 trees. The oldest are about 500 years old and the tallest are between 180 and 220 feet.

Franklin spearheaded the effort to install the crane. He likens it to an observatory. Like observatories pointed toward space, researchers from all over the world propose projects and schedule time at the crane. Franklin says they average 26 to 27 research projects each year and adds, “We’ve just finished a period of very, very heavy study related to the carbon cycle in these forests.”

Scientists are interested in a forest’s carbon cycle because, through photosynthesis, the forest soaks up large amounts of one of the most common greenhouse gasses, carbon dioxide. That’s one big reason researchers also have equipment on the forest floor and even probing underground to try to get a full picture of how the forest operates.

They’re exploring not only how a forest soaks up carbon dioxide, they’re researching how forests also give off carbon dioxide. Research scientist Matt Schroeder says forests give off carbon dioxide, “As the leaves, the needles, the wood here on the forest floor are decomposed.” Also, he says, “as bacteria and fungus and bugs eat some of the organic material in the soils…they exhale CO2 (carbon dioxide) just like we do.”

At several locations automated clear plastic boxes briefly close at regular intervals and measure the amount of carbon dioxide coming off the forest floor. Temperature and humidity gauges constantly monitor conditions at several places on the forest floor, and in the canopy.

In the canopy, researchers put numbered metal tags on the branches, allowing them to return to the same branch each year, measuring how much growth there’s been and how rain and temperatures may have affected that year’s growth.

This year the Douglas Fir trees have presented scientists with a mystery. The trees in the area of the crane have sprouted many more cones than usual. Bible notes previous research has shown that such growth can come in cycles, but he adds, “This kind of cone crop we have not seen since the crane was installed.”

Is it weather or climate related? Or has something changed with the soil, or is it something else? While researchers don’t yet have answers, with help from the Wind River Canopy Crane, they’re sure to get closer to the answers faster than ever.