The 1970-80s outbreak effects were far-reaching on the resource as a whole and on future timber supplies. Spruce-fir inventory declined as the budworm caused mortality, growth loss, and damage to regeneration. Other factors were at work. Mill capacity during this time increased, and there was a strong demand for wood products. These demands as well as salvage cutting to thwart loss to the infestation increased cutting levels. The age structure of the forest also played a part, which led to a decline in fir stock due to aging, rot, and suppression.
Significant effects from the outbreak included:
- Defoliation of balsam fir by the budworm led to 84-97% mortality; 30-66% mortality was found for red spruce.
- The outbreak killed between 20 and 25 million cords of spruce and fir.
- Salvage logging led to increased clearcut harvesting–45% of the forest harvested in 1989 were clearcut.
- There was a significant increase in snowshoe hare population as a consequence of clearcutting.
- Protection efforts cost the state and federal governments, as well as private landowners, millions of dollars.
Annual SBW defoliation of spruce-fir stands in Maine from 1972-1989. Maps were digitized from the Maine Forest Service sketch maps by Hennigar et al. (2013).
- The glut of wood on the market kept pulpwood prices low.
- The increase in logging stimulated more mechanization.
- Long-term decrease in logging jobs as output decreased post-outbreak.
- Insecticides were limited to organophosphate and carbamate chemicals; only large aircraft were available to treat broad areas.
- The Maine Forest Service assumed control over the entire SBW management program, which is unlikely to happen again in the future.
- The impact of the SBW on the forest composition substantially affected the food sources and wildlife habitat for birds and other species.
- Numerous negative political and legislative policy consequences due to poor communications and misunderstandings among landowners, government bodies, and the public.