Objectives:
To investigate the effects of:

• Harvesting season (spring vs. summer) on soil disturbance.
• Harvesting method (pushover vs. handfalling) on soil disturbance.
• Harvesting method and silvicultural system (single tree vs. group selection) on control of Armillaria root disease.
• Harvesting method, silvicultural system, and season of harvest on regeneration establishment and stand development.

Experimental Design:

Treatments:

• Spring harvesting was conducted between June 17 and July 23, 1996.
• Summer harvesting was conducted between July 24 and September 15, 1996.
• Single tree selection preferentially removed Douglas-fir, Interior spruce, lodgepole pine, western larch and yellow pine in that order. Trees with poor form and vigour, thinning crowns, and other damage were targeted for removal. Some undesirable stems were retained to preserve the desired diameter class distribution to meet wildlife objectives. Sufficient trees (layer 1) were retained to approximate 17 m²/ha of basal area.
• Group selection harvested five to seven approximately 0.1 ha openings per treatment unit. All stems within Armillaria centres were marked for removal.
• Hand falling used one faller/bucker and one crawler-tractor, with narrow trails and single-pass random skidding to the trails.
• Pushover falling used one small excavator, a bucker and  a skidder. In single tree selection, the excavator was restricted to 5 m from the trail. This resulted in a central swath of inaccessible trees. Stumps were bucked within the harvest area.

Layout:

• There are two study sites in the same area.
• Each study site contains eight treatment units, each approximately 2 to 4 ha in size.
• Before harvesting, a permanent cruise plot was established in each treatment unit.
• Treatments were randomly assigned to each treatment unit

History:

• 1996 Study design and pre-treatment stand measurements and soil and foliar sampling.
• 1996 Harvesting, and first post-harvest measures
• 1997 Hyphaloma innoculation
• 2001 Permanent regeneration plots established

Status: Active

Reports And Publications:

Sacenieks, K. and H. Pinnell. 1998. CASE STUDY: Harvesting options in highly constrained IDF stands in the Rocky Mountain Trench: Whitetail Brook, Invermere Enhanced Management Pilot Project Area. Research Summary 038, Nelson Forest Region.

Kishchuk, B., D. Maynard and M.Curran. 1999. Calcareous soils. Canadian Forest Service, Pacific Forestry Centre Tech. Transfer Note 15