Mar 07, 2018
THEME: Sustainability

A (Wood-clad) Natural History for Minnesota

Minnesota is home to four distinct ecological provinces, or ‘biomes.’ The largest of these is the Laurentian Mixed Forest – mostly comprised of aspen, spruce, fir, and eastern white pine trees. Prior to European settlement, it extended as far south as Chisago County, all the way up to Canada, and the North Shore of Lake Superior. In the late 19th century, the Minnesota North Woods were aggressively logged for white pine – the timber industry feeding the growth of new boomtowns like Stillwater, Minneapolis, and Duluth. Around the same time, in 1872, the Bell Museum of Natural History was established by the Minnesota Legislature to “collect, skillfully prepare, display, and interpret Minnesota’s diverse animal and plant life.”

Extent of the Laurentian Mixed Forest. Image via Wikimedia Commons.

Extent of the Laurentian Mixed Forest within the United States. Image via Wikimedia Commons.

The Minnesota Legislature entrusted the governance of this new museum to the University of Minnesota. With the settling of the prairie, and the mining, quarrying, logging, and railroading that followed, it’s not difficult to imagine what the Bell’s founders were thinking. The plow follows the ax, and industrial development has a huge impact on natural environments. Today the Bell Museum continues to pursue this mission, working to “educate and connect people to our natural world and universe.”

A Living Diorama

With its internationally renowned collection of dioramas, the new Bell Museum  building will act as a living diorama, framing experiences of Minnesota at scales from microscopic to galactic. The entire museum site is designed as a learning landscape – its surfaces configured to tie people, nature, and the environment together. Even the building’s skin offers a lesson about the natural history of our state.

As a site for Minnesotans to learn about the place we inhabit, it was critical to the University of Minnesota and the Perkins+Will design team that the new building feature local materials. The Laurentian Mixed Forest biome, home to over 6 million acres of FSC certified forests, is the source for all of the white pine cladding on the new Bell Museum building.

Because of its clear grain, stability, and durability, white pine has historically been in great demand for use in furniture, building materials, and – most famously – masts for sailing ships. The largest tree species in Eastern North America, some measured over 200 feet tall and 8 feet wide. In 1900, 2.3 billion board feet of lumber was cut from Minnesota forests.

Eventually, even the most remote forests had been harvested. In Virginia, Minnesota, the world’s largest white pine mill shut down in 1929. By the mid-1930s, large white pines were exhausted, and most lumber outfits had moved on to the Pacific Northwest. The Minnesota timber industry shifted to pulpwood for paper.

Today Minnesota forestry is focused on sustainable practices. Long-term productivity and responsible stewardship of forest resources is prioritized. The Minnesota Forest Resources Council was established by the Sustainable Forest Resources Act of 1995. Minnesota forest resource interests work together to protect forests and encourage management that supports healthy ecosystems and healthy human communities.

White pine lumber has been used for exterior cladding for centuries. Today, because of responsible forest management, it’s readily available again in Minnesota. Its strong association with Minnesota history makes white pine an ideal expression of the Bell’s mission.

A (More) Durable Product

Research at the University of Minnesota has helped enhance processes that increase the durability of white pine lumber. The Natural Resources Research Institute (NRRI), based at the University of Minnesota Duluth, is working to upgrade the durability of several Minnesota tree species with thermal modification processes. Just recently, the Bell Museum building itself became clad in thermally modified white pine.

Under construction, but starting to show its wood-clad facade.

Under construction, but starting to show its wood-clad facade.

Thermal modification is a heat and steam process that ‘cooks’ wood, modifying its cell structure to increase its durability and stability. Thermally modified wood is more resistant to moisture absorption and rot, and over time it weathers to a warm gray color.

From the street, the wood siding displays a rough surface. The design team worked with the University of Minnesota, McGough Construction, and Intectural, Inc. to develop this distinctive siding pattern of varying board widths and depths. This variegated texture provides generous surface area to enhance its drying capacity after exposure to moisture.

Finally, the white pine boards are left rough-sawn and unfinished. Reduced cost is one benefit of this irregular surface, but for the Perkins+Will design team the rough-sawn finish provides a window into the origin story of the building envelope. With minimal finishing, the thermally modified boards are simply cooked – cut – and installed – the rough surface recalling the uneven bark of a white pine tree.

The new Bell Museum will be a destination for anyone that is curious about life. The exhibits, classes, landscape, and the building itself will enable journeys of discovery, both microscopic and grand. When visitors come to the site and walk the surrounding learning landscapes, the building’s white pine wood cladding will offer an opportunity to learn a natural history story about sustainable forestry practices, University of Minnesota research, and our natural world.

The Museum opens this July.

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