Scientists in the gondola were able to reach the canopy in a 560-foot
circle of the forests.
The 25-story construction crane used since 1995 to investigate
such things as how Pacific Northwest forests absorb carbon dioxide,
obtain sufficient water and resist attacks by pests and diseases
is being pruned back to just the tower.
The Wind River Canopy Crane, located in a 500-year-old forest
near Stevenson in southwest Washington, has been operated cooperatively
by the University of Washington, the Forest
Northwest Research Station and the Gifford
Pinchot National Forest.
The partners say the jib – the arm of the crane – is
being removed because the Forest Service faces budget shortfalls
and replacement parts for the crane are becoming more difficult
to obtain. Funding for the crane’s operation has largely
come from the station’s budget. The jib will be removed when
money is available, possibly this summer.
Gone will be the ability to carry a gondola with researchers and
instruments from the bottom to the top of trees as tall as 220
feet in a 560-foot circle of old-growth forest. The Wind River
crane has the farthest reach of any of the nine forest canopy research
cranes operating in the world today.
Remaining will be the 230-foot tower with sensors that collect
data about how the carbon dioxide is absorbed and released by the
forest, work under way since 1999. Because of the crane, the UW
and the Forest Service have one of the world’s longest, continuously
collected data sets of carbon flux from a forest, according to Jerry
Franklin, UW professor of forest resources, who was the prime
mover in the 1990s for landing the $1 million project.
The carbon flux data are important as policymakers and citizens
consider how to manage forests to maximize the amount of carbon
they hold, he said.
Work at the crane site produced some of the first data to substantiate
what Franklin and other scientists suspected in the 1980s: that
old-growth Douglas fir forests weren’t emitting more carbon
than they were absorbing.
“Data collected at the crane site revealed that old growth
forests are a sink for carbon,” Franklin says.
A growing number of partners, ranging from the National Oceanic and
Atmospheric Administration to the Smithsonian Institution Global
Earth Observatories, count on carbon flux and isotope data being
collected at the Wind River facility from the tower. Recently the
site was chosen as the Pacific Northwest core site for the National
Ecological Observatory Network, known as NEON, a major new initiative
of the National Science Foundation.
The Liebherr 550 HC crane was purchased used and erected in 1995.
It had previously been used at construction sites.
The crane has facilitated other significant scientific discoveries,
Franklin says, including seminal research on the structure of forest
canopies, physiology of northwestern tree species, carbon and water
cycles in forests, forest productivity and health, and the contributions
of forest canopies to biodiversity, including birds, bats and insects.
Researchers and students using the crane have generated more than
The crane has, for example, enabled Pacific Northwest Research
Station ecologist Rick
Meinzer to study how very tall trees get
the water they need to survive centuries of environmental extremes.
During annual cycles of summer drought, trees rely on internal
water storage to stabilize the supply of water to foliage high
in the canopy, and on their deep roots to bring water close to
the surface to feed shallow roots that might otherwise die every
“Research using the crane has provided important insights
about the factors that limit maximum tree height and why height
growth slows drastically as a tree becomes taller,” Meinzer
says. “The tower will continue to be part of the nationwide
network for continuous camera observation of changes in the timing
of events such as leaf emergence and senescence, which are being
influenced by climate change. Camera images are updated continuously
and are available to both scientists and the public through websites.”
The tower site and experimental forest also will continue to provide
educational opportunities for high-school and college students
focused on forest ecology, population dynamics and functions such
as the cycling of carbon, water and nutrients.
The Pacific Northwest Research Station is headquartered in
Portland, Oregon. It has 11 laboratories and centers in Alaska,
Sampling of findings, opportunities
Scientists interested in comparing the canopies of young and old-growth Douglas fir forests used the crane to document how completely different the structure – or architecture – of the older forest is.
The complexity of older canopies – with branches and foliage from the bottom to the top of trees – is one reason older forests are good at taking up carbon dioxide, research at the crane showed. There’s a lot more “leaf area” than in younger forests where foliage is mainly at the tops of trees.
Research at the crane has revealed some of the ecosystem advantages of complex forest canopies and insight into how younger forests might be managed for more complexity if we wish.
As to the puzzle of how old growth Douglas firs can thrive for centuries after they stop growing taller and their crowns stop getting fuller, work at the crane was the first to definitively show that old trees generate new growth from dormant buds on their lower branches. It’s more proof of the active growing in stands once considered to be in a state of decay.
The crane has provided educational opportunities for thousands of college students, teachers and natural resource professionals. At the secondary level, among other things, the crane was part of a television broadcast that reached 7 million students in North America.
The crane is located in the Wind River Experimental Forest of the Gifford National Forests where for nearly 100 years studies have been conducted into nursery practices, seedling survival and growth, genetics and ecology.