Assessing the Use of Shrub-Willows for Living Snow Fences in Minnesota
Diomy Zamora, Eric Ogdahl, Gary Wyatt, David Smith, Gregg Johnson, Dean Current, Dan Gullickson
Report no. MnDOT 2015-46
Topics: Snow and ice control
Blowing and drifting snow adversely affect winter driving conditions and road infrastructure in Minnesota, often requiring removal methods costly to the state and environment. Living snow fences (LSFs) - rows of trees, shrubs, grasses, or standing corn installed on fields upwind of roadways - are economically viable solutions for controlling drifting snow in agricultural areas. Despite incentives and financial assistance by state and federal agencies, farmer adoption of LSFs is low, in part due to concerns about removing cropland from production. Of recent interest in Minnesota is the use of shrub-willows (Salix spp.) for LSFs, as they have been successfully implemented for LSFs in other states and are researched increasingly as a marketable biomass product for bioenergy production. To evaluate the potential of willow LSFs for multiple benefits in Minnesota, we established studies in Waseca, Minnesota, 1) to test different designs of willow LSFs in their ability to trap snow, 2) to compare the growth of willow varieties to willows native to Minnesota and other species traditionally used in LSFs, and 3) to assess the costs of planting and establishing a willow snow fence and the viability of biomass harvest. We found all shrubs to have generally high survival rates, with willows tending to have higher growth than traditional LSF shrubs. Additionally, willow LSFs may have the potential to trap all blowing snow at the study site as soon as three to four years after planting. This may provide earlier road protection than other shrub species traditionally used in LSFs. Regarding economics, willows can provide affordable LSFs relative to traditional LSF species, although harvesting for biomass may only be appropriate for very long transportation corridors.