If you’ve been around the ski world awhile, you might remember the “Stop the Brutal Grooming” campaign that sprang up in the 1990s. The bumper sticker protests focused on ski areas’ habit of turning fresh powder into beginner-friendly corduroy, but it could also apply equally to bulldozing ski trails to flatten terrain and remove boulders, stumps, and other natural features. The practice is common, but it damages the ecosystem, costs more in off-season maintenance, and only extends the ski season by a week, says a new study by the University of California, Davis.

There are two methods of trail building. The first is clearing, where trees, stumps, and other tall obstacles are removed by hand. The second is grading, where heavy machinery is used post-clearing to strip the run down to golf-course smoothness. UC Davis ecologist Jennifer Burt studied ski areas in California’s Sierra Nevada mountains and found that cleared runs reduce plant diversity and, by denuding the slope and eliminating topsoil, dramatically increase erosion.

What’s surprising is that cleared runs are ecologically more similar to surrounding forests than to graded runs. Indeed, cleared trails might even offer benefits. The soil stayed intact and there was a greater diversity of both plant life and wildlife.

“We have encountered a marked tendency…to consider all ski runs equal. In contrast, our research indicates that cleared ski runs present a viable, ecologically preferable alternative to graded ski runs,” Burt writes. “This begs the question as to why ski runs are graded.”

Well, it’s easy to understand. Graded runs require about 15 fewer inches of snow to open. Ski resorts are a dodgy business and any advantage, perceived or real, will be grabbed. The fact that graded runs are only skiable one week more per season than cleared runs would seem inconsequential to a resort operator, even given the increased off-season costs in planting and erosion management.

But there are bigger issues than the concerns of ski-resort accountants. As Burt points out, “Most large downhill ski areas in the United States are on lands managed by the USDA Forest Service, a federal agency charged with encouraging multiple uses while attempting to protect and maximize ecosystem services…however, ski areas are managed almost exclusively for recreation, when they might also be managed to minimize negative impacts on compatible ecological services, such as water storage, nutrient cycling, and maintenance of biodiversity.”

It seems an easy conclusion to reach: “Because grading is more damaging to multiple indicators of ecosystem function, clearing rather than grading should be used to create ski slopes wherever practical.”

Read Burt’s study for yourself. Find it here in PDF. LINK.

Photo courtesy of UC Davis.

Tagged as: environment, skiing