Table 2 Overall volume losses (mortality and growth) linked to the spruce budworm outbreak and volume gains attributable to treatments for the three host species according to the different protection scenarios. This information was used to estimate the benefits used in the cost–benefit analysis. The benefits were estimated as the gains in volume that can be attributed to the protection scenarios by subtracting volume losses through mortality and growth losses per hectare that were observed in each protection scenario from volume losses that were observed in the no protection scenario
| Â | Losses | Gains | ||||||
|---|---|---|---|---|---|---|---|---|
Scenario | Balsam fir | White spruce | Black spruce | Total | Balsam fir | White spruce | Black spruce | Total |
(m3/ha) | (m3/ha) | (m3/ha) | (m3/ha) | (m3/ha) | (m3/ha) | (m3/ha) | (m3/ha) | |
No protection | 91.4 | 7.3 | 13.9 | 112.6 | 0 | 0 | 0 | 0 |
Btk every 3Â years | 56.6 | 2.9 | 4.3 | 63.8 | 34.8 | 4.4 | 9.6 | 48.8 |
Btk every 2Â years | 21.9 | 2.2 | 3.8 | 28.35 | 69.5 | 5.1 | 10.1 | 84.3 |
Standard | 6.7 | 2 | 3.8 | 13 | 84.7 | 5.3 | 10.1 | 99.6 |
Intensive | 5.8 | 2.2 | 1.2 | 9.3 | 85.6 | 5.1 | 12.7 | 103.3 |