Objectives:

• To examine partial harvesting prescriptions within and adjacent to FENS (Forest Ecosystem Networks), while attempting to maintain functional old-growth ecosystems; and
• To compare the effects of different levels of partial harvesting on wildlife species which use old-growth attributes.

For the wildlife component, this project tests the following specific hypotheses:

• The diversity and composition of bird species does not change as a result of the treatment
• The density of active nests or dens of cavity nesters does not change as a result of treatments, and
• The abundance of woodpeckers feeding within the treatment units does not change as a result of the treatments

Experimental Design:

• Factors:
  • Site: random, with two replicates within each of two BEC variants (IDFdm2 and MSdk)
  • Basal area retention: fixed with three levels (100%, 70% and 40%)
• Dependent Variables:
  • density of active cavity nests per treatment unit
• Observational Variables:
  • Presence of avian species
  • Frequency of feeding use
  • Pre- and post-harvest stand structure/composition
• Layout:
  • Each treatment unit is approximately 20 ha, and contains a systematic sampling grid with a randomly located origin.
  • Each grid is 3 x 3 with a spacing of 100 or 150 m, depending on area and shape of the treatment unit.
  • Wildlife data is also collected by observation throughout the treatment units.

History:

• 1997 - Site selection and pre-treatment data collection
• 1998 - First post-treatment data collection.
• 1999 - Post-treatment data collection
• 2000 - Sites in MSdk monitored

Status: Active

Reports and Publications:

Steeger C. and H. Quesnel, 1998. Impacts of partial cutting on Old-growth forests in the Rocky Mountain Trench: Interim Report. B.C. Min. For. Invermere District, Enhanced Forest Management Pilot Project, Project Summary, Report Number 9.

Comments:

Pre-harvest stand structure had a strong influence on the development of the silvicultural system. Although infrequent in the treatment units, western larch has been the main choice of the primary users both before and after treatment, Douglas-fir and lodgepole pine were less frequently used.