Retention Treatments

Retention treatment - Unlogged control

1) Unlogged control

Retention Treatment - Clearcut

2) Clearcut

No trees of any size retained

3) Single tree retention

  • Approx. 25 mature trees per hectare retained in a uniform distribution
  • Preference given to retaining dominant old Douglas-fir
Single Tree retention treatment

4) 30% patch retention

  • Retention of 30% of the stand area in patches (“islands”) containing mature old Douglas-fir and their neighbours
  • No cutting within the retained patches
  • All trees of all sizes cut in the 70% of the stand area that is cleared
  • Retained patches about 30-40 m in diameter, with no connectivity between retained patches; patches can be irregularly shaped
30% patch retention

5) 60% group retention with thinning

  • Retention of 60% of the stand area in connected patches containing mature old Douglas-fir and their neighbours

  • Retained patches thinned from below by reaching in with a machine

  • All trees of all sizes cut in the 40% of the stand area that is cleared

  • Retained areas and gaps can be irregularly shaped

60% group retention with thinning
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