Logging Options to Minimize Soil Disturbance in the Northern Lake States

Abstract Forest harvesting is likely to have greater impacts on site productivity than any other activity during the rotation. We determined effects of commercial, winter-logging of four aspen-dominated stands on site disturbance and development of regeneration on clay soils in western Upper Michigan. A large skidder caused deep rutting on 20% of a site in a thinning that removed 7.8 m2 ha-1 (34 ft2 ac-1) of basal area, and on 38% of a clearcut site. After the first growing season, 45% of the clearcut had no aspen regeneration, and 82% had less than the recommended minimum of 15,000 (15 k) suckers ha-1 (6 k ac-1). Options that can be utilized to minimize logging impacts include: (1) excluding riparian areas and poorly drained inclusions from cutting units; (2) dry season harvesting; (3) plowing snow from (or packing the snow on) skid trails and landings, permitting them to freeze; (4) felling with delayed skidding until trails and landings have frozen; and (5) application of best management practices (BMP) recommendations such as progressive (back-to-front) harvesting. Each of these should have minimal effects on logging costs and may be economically advantageous. As an interim guide, a minimum of 7.5 cm (3.0 in.) of soil frost is recommended for small equipment and 15 cm (6.0 in.) for large equipment. BMP guides could be effective in communicating management objectives to foresters, sale administrators, contractors, and operators, increasing their awareness of (and sensitivity toward) soil disturbance and thus, contribute to sustaining future productivity.