The Mount Tom adaptive management trial was initiated in 1999 to assess whether group selection silvicultural systems, conducted at an operational scale, could main-tain attributes of mountain caribou (Rangifer tarandus caribou) winter habitat in high-elevation Engelmann spruce-subalpine fir (ESSF) forests of east-central British Columbia. The results from this trial confirm that a group selection silvicultural system using a range of opening sizes from 0.1 to 1.0 ha can provide acceptable regeneration per-formance of subalpine fir and Engelmann spruce. The average height of all planted seedlings in the main trial generally exceeded the free-growing standard goal of 80 cm. The exception was subalpine fir seedlings planted on preferred natural microsites in CP551-1. Heights of those seedlings averaged 72 cm after 10 years, but they will easily exceed 80 cm within the 20-year allowance and meet free-growing standards. However, trees in these ecosystems that border alpine areas are challenging to re-generate. For example, slight changes in logging practices such as roadside versus stumpside processing can affect regrowth of competing vegetation and, in turn, re-generation outcomes. Seedlings must be of high quality, and planting microsites should be selected with care. Planted seedlings may grow poorly next to the edge of the openings, especially those seedlings with northern exposures. Mechanical mounding may alleviate some of the limiting factors associated with these cooler shady sites. Budworm is always a concern and can damage seedlings that are re-generating in small openings. The harsh and variable environment of high-elevation forests requires the forester to adapt practices to suit individual sites more so than in other ecosystems. As with any forestry research, 10 years of data cannot predict long-term results. Continued monitoring will be required to determine the final trial outcomes.
Newsome, T.A., Brown, K.R.; Nemec, A.F.L.. 2017. Ten-year Survival and Growth of Planted Conifers in a Group Selection Silvicultural System: Mount Tom Adaptive Management Trial. Forests, Lands, and NR Operations. Research Report (FLNRORD). TR107