|
|
The center incorporates solar panels, efficient design, geothermal heat and roof runoff draining to a rain garden February 2008A legacy in pineFrom plantation to pillar and post, pines with an environmental heritage have been transformed into one of the greenest buildings on earth. Kathryn A. Kahler
Pines, like other blessings, come to him who waits. When the labor of planting is done, you wait for a rain. When the plantation is safely rooted, you wait three years for real growth to begin. Then, for a decade or two, you wait all year for May to come, for buds to burst, for waxy "candles" to reach skyward, each year a little farther: first a foot a year, then two feet a year, finally sometimes three feet a year. If, during the pyramiding period, your own clock shows signs of running down, you may gain from your trees a curious transfusion of courage. Pitch, like blood, is thicker than water. Perhaps Aldo Leopold foresaw the dilemma his children would someday face when he wrote this essay in the early 1940s. They had, after all, worked and played among the pines during their "pyramiding" process and watched over the plantings during the seven decades since. The Leopold pines were in their blood when in 2003 the family was asked to approve a plan to selectively cut some of them. The plan was to use the thinnings to build the Aldo Leopold Legacy Center a mile from the Leopold Shack, northeast of Baraboo near the Wisconsin River. But approve the plan they did and construction of the center, named for one of the country's most influential conservationists, was completed in April 2007. It soon received an award from the Forest Stewardship Council (FSC). More than three-quarters of the wood used to construct the building was FSC-certified, 92 percent of which was harvested on-site and locally processed. Last November, the center was certified by the U.S. Green Building Council as the "greenest" building in the world. The council's LEED (Leadership in Energy and Environmental Design) program gave the center the highest rating of all buildings ever assessed for its energy efficiency and use of locally harvested products. Where it all startedThe pines took root in the sands of northeastern Sauk County on the farm Aldo Leopold bought as a family hunting camp for $8 an acre. Worn-out and abandoned, the farm was destined to become a place of respite for Leopold, his wife Estella and their five children, and inspiration for his most famous book, A Sand County Almanac. Leopold's budding land ethic, accompanied by persistence and much trial and error, transformed the barren land into a haven for wildlife and humans alike. Between 1936 and 1948, the family planted, watered and cared for 40,000 pines obtained from state nurseries. Although 95 percent died in the early years due to the Dust Bowl, by the turn of the millennium thousands of white and red pines towered above the farm. By 2003, it was apparent that the pines needed further care. As pine plantations mature, it's common for managers and landowners to thin out the smaller, weaker trees to provide better growing conditions for the more stalwart of the stand. Dan Pubanz, a consulting forester for Clark Forestry in Baraboo, was hired by the Aldo Leopold Foundation to make an assessment of the pines. Pubanz concluded that many of the red pines were at a critical stage. They were stressed from competition for sunlight, water and soil nutrients to a point that an insect attack or drought could kill a large number of them. The Leopold family and foundation agreed to a careful thinning but, in the vein of their father's land ethic, sought to find good use for the thinnings. "As fate would have it, we had been considering the notion of building a new center for a couple of years," recalled Buddy Huffaker, the Aldo Leopold Foundation's executive director. "When the evaluation of the health of the pines was done and they were found to be in decline, the two things moved forward in unison from then on." A design team headed by Kubala Washatko Architects developed plans for a 13,000 square-foot, three-building complex that would use as much of the wood from the pines as possible and incorporate innovative techniques rarely tried before. In addition, the center was designed as a model for energy efficiency with a goal of producing 10 percent more energy than the buildings consumedv Blueprint for harvestAll told, the foundation's ecologist Steve Swenson marked 1,000 trees for harvest, including 450 red and white pines from the Leopold family stands and 50 trees of various other species that would be put to structural and non-structural uses. "Structurally, we milled columns and beams from our trees that created the majority of the interior skeleton of the building," said Swenson. "We also used our site-harvested wood for non-structural building materials like interior and exterior siding, windows and doors; ceiling and porch decking; flooring; window and door trim; baseboards; batten strips; counters; cabinets and furniture." Besides the red and white pine, site-harvested species included red, black and white oak; black locust; black cherry; red maple and aspen. Len Fike, proprietor of Fike Forest Products of New Lisbon, was chosen to harvest the pines. Harvest began December 27, 2005, and after some stops and starts due to variable weather, was concluded in February 2006. Fike used a low-impact harvester-processor that both held and selectively cut trees from the stand without damaging the remaining trees. The processor used large arm-like clamps to grasp a tree, then a chainsaw swung out from its housing at the bottom and cut the tree at the base. The arm then swiveled with the tree in its grasp and dropped the massive trunk in the desired direction. Once the pine was on the ground, large rollers slid the tree along and a chainsaw automatically limbed and cut the logs to a desired length. The harvester moved on wider, tank-like tracks that greatly reduced soil disturbance in the forest.
Foundation staff learned new respect for professional loggers. Huffaker recalls that when weather made it difficult for Fike to get his equipment into the woods, staff tried to do some of the cutting by hand-felling and using a light tractor. "It became apparent to us that we were doing more damage than the bigger equipment," said Huffaker. "It showed us the value of using a good logger and how good they are at what they do." The largest logs were trucked just one mile down the road to the construction site where local sawmill operator Troy Zietlow milled them into structural posts and beams. "The butt log, which is the lowest log of a standing tree, and obviously the largest, was cut at 17 feet long and hauled to the building site," Swenson recalled. "The posts and beams milled on-site were mostly 8 x 8 and 8 x 10 inches wide, but also 8 x 12 and 8 x 14. "Some trees were large enough in diameter to make two 17-foot logs for structural use, but typically after the butt log was cut at 17 feet off the ground, the next logs were cut to 8 feet 6 inches in length down to a diameter of 6 inches and hauled away for milling." Eleven truckloads of these smaller diameter logs, or 115 cords, were shipped an hour's drive to Samsel Limited, a family-owned sawmill near Hancock. Samsel handled milling, kiln drying and finishing of more than 70,000 board feet of wood, including pine paneling, red maple ceiling decking and oak siding. About 70 skinny and tall red pine logs, ranging in diameter from six to eight inches, also became an integral part of the center's structure. Too small to be milled into structural beams, such logs are usually considered "substandard" for most construction and are more typically ground for pulpwood or other uses. In this project, designers employed an innovative technique – leaving the logs in the round – for use as trusses, purlins and rafters. By keeping the logs in the round the strongest part of the wood, the sapwood, remains intact. The round-log trusses are so strong they can span the roof of a 30-foot deep building without any internal support columns. The center's three-season outdoor classroom, made entirely of round logs, is the best example of this technique. "We didn't want to pass judgment in the field on which part of the tree was the best structurally," Swenson said, "so we decided to get them down to the building site whole and have them looked at by a professional grader." In all, some 70 logs ranging from 37 to 80 feet long were trucked whole to the building site. In keeping with the other low-impact techniques used in construction, staff decided to "peel" or remove the bark from each log by hand. More than 200 volunteers were recruited over a period of several weeks and spent about 500 hours peeling the logs. "The teams used draw knives to peel the logs," Swenson explained. "The knives are curved and look like bicycle handlebars. The peelers straddle the logs and pull the knives toward themselves, peeling and turning the logs as they move down the trunk." Volunteers who each dedicated at least two hours of their time received special recognition. Their names are engraved in a plaque made from one of the Leopold pines and displayed at the center.
The round logs used for trusses were graded for quality and structural soundness by Mac Garcia of Expedition Log Homes. Once graded, truss construction commenced. Each truss was formed from a bottom chord parallel to the ground, a top chord forming the angled roofline of the building, and shorter web pieces in between. The webs were attached to the chords at all weight-bearing surfaces with foot-long steel screws. Compression from the weight of` the roof helps stabilize the trusses, as do steel plates inserted inside the beams at critical points and threaded steel pipe running diagonally between the webs. Finally, the tops of the pines that were deemed too small for building materials were ground and made into paper used to print a commemorative edition of A Sand County Almanac. Researchers from the Forest Product Laboratory in Madison and students from UW-Stevens Point's Paper Science Laboratory collaborated to make paper from the 500 pounds of pine pulp, strengthened by pulp from other softwoods and hardwoods. Lessons learnedHuffaker hopes the Leopold project contributes to a trend toward more intelligent consumption of forest resources, where more forest products now considered unusable will be available to a broader public. "Using small diameter trees and thinnings is certainly a prime example of finding a market for something that's currently undervalued," said Huffaker. "The Leopold center reinforces that goal in other ways. The ceiling decking, for example, is red maple which economically and ecologically is creating challenges for landowners. This species shades out oak woodlands that are converting to red maple. Using red maple for finishing projects creates a market for it. "Another example is our oak flooring. When the builders came in to do the flooring, they asked where the materials were. We pointed to the pile of wood and they said, 'You're kidding, that's terrible!' By the time they were done it was beautiful. Small-diameter wood can't be purchased at most commercial lumber yards because its imperfections don't meet many consumers' expectations. People these days expect the flawless finishes they see in artificial flooring made with composites. We hope that by showing the general public its beauty, they will want it in their homes. That would further eliminate waste in the wood products industry." Clyde Samsel, owner of the company that milled some of the hardwoods and small pine not used for structural components agreed. "I knew the job would be very difficult for our sawyer, but we would never reject low-grade logs or discourage people from marketing low-grade woods. It can be successfully marketed as 'character wood,'" noted Samsel. "If you have a floor made out of wood with lots of defects, it's very interesting to look at." Steve Swenson believes the Leopold center can also serve as an example of a trend away from overbuilt designs that use more wood than necessary. "Ironically, it's in environmental learning centers where we often see these nostalgic 'lodge aesthetic' designs," Swenson explained. "In our case, we feel fortunate that our commitment to site-harvested wood forced the design process to draw a tighter connection to sustainability in ways we were not considering." In Leopold's words, it also appears there was a "curious transfusion of courage" involved in the process. All along the way, partners put old methods aside and looked at the project as a way to use innovative, ground-breaking techniques as examples for us all. As Leopold observed, the decision about which tree to cut, spare, or plant is not just made in the woods by a forester, but in part by architect, engineer, and each one of us selecting a home, furniture or flooring. "The long and short of the matter is that forest conservation depends in part on intelligent consumption, as well as intelligent production of lumber." Kathryn A. Kahler writes from Madison. |
Wisconsin Department of Natural Resources
about ||
freelance ||
legal notices ||
top of page
WNR Webmaster
Need this information in an alternative format? Call (608) 266-1510
Send Letter to Editor
