Strong winds approaching 150 km/hour in October 1975 caused widespread spruce blow-down and breakage in the upper Bowron river valley and to a lesser extent, in adjacent valleys. Several warm winters with heavy snow packs and early springs set the conditions for one-year life cycle spruce beetles. Overlapping one and two-year cycle beetles resulted in huge beetle flights and dramatic expansion and intensification of the infestation.
The subsequent outbreak killed 40-60% of the mature spruce and, in response, approximately 5 million m3 of timber was logged from 1981-1987. Licensees were compelled to harvest 25-30 years of normal annual allowable cut in this compressed time frame. Within the 175,000 ha outbreak area, 48,000 ha were harvested, and all openings were reforested by 1999.
The management response and lessons learned from the outbreak will be outlined. The presentation will precede a 30 minute Westland video presentation of "The Biggest Clearcut".
Dr. Allan Costello, 250.960.5658
Dr. Henry Philippe, 250.960.5424