Site preparation for establishing lodgepole pine in the sub-boreal spruce zone of interior British Columbia: the Bednesti trial, 10-year results

Nine site preparation techniques for reestablishing productive lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) forest in the Stuart Dry Warm Sub-Zone of the Sub-Boreal Spruce Zone (SBSdw3) of interior British Columbia on 'NSR backlog' (i.e., by provincial criteria, not-sufficiently-regenerated) sites are compared in a randomized block experiment, with one 48-tree, 750 m(2) plot of each treatment in each of five blocks. Low fertility, compact subsoil, and low water-holding capacity in a rooting zone as thin as 10 cm in lower slope and level positions are the main limiting factors. After 10 growing seasons, pine survival was 90-97%; mean stem volumes in 7 treatments were 41-235% higher than the control, and one treatment gave 29% less volume. Results from mounding and patch scarification were virtually identical. While site preparation can increase early growth of lodgepole pine, especially on the more poorly drained parts of sites such as Bednesti, planting directly into sheared, windrowed ground will give satisfactory survival and growth. (C) 2000 Elsevier Science B.V. All rights reserved.