Effect of site preparation on soil properties and vegetation cover, and the growth and survival of white spruce (Picea glauca) seedlings, in Saskatchewan

A clear-cut aspen stand, near Prince Albert, Saskatchewan, was treated in J uly 1994 to encourage the establishment of mixed aspen-white spruce forest. Site preparation methods included use of a v-blade, disc trencher and Brac ke mounder, as well as a drum chopper in combination with the disc trencher and Bracke. The study site was planted to white spruce in May 1995 using 3 + 0 nursery stock. During 1995 and 1996, soil and atmospheric conditions w ere monitored along with density and composition of regrowth vegetation and survival and growth rates of the white spruce seedlings. Although conditio ns for seedling establishment did not differ substantially between any of t he treatments, the two drum chopper combinations were the most favourable. Both produced moderate height and biomass increases and low mortality rates , at the same time reducing competing aspen and shrub growth. The v-blade t reatment also restricted encroachment of competing plants, and because of i ts lower cost makes it the preferred treatment method to establish a mixed aspen-white spruce forest stand. (C) 2000 Elsevier Science B.V. All rights reserved.