Clearcutting involves harvesting all the trees in a stand regardless of their species or marketability (Figure 4-7). Clearcutting simulates regeneration conditions after a catastrophic windstorm, fire, or other disturbance. This method creates conditions optimal for regeneration of light-demanding species adapted to growth in full sunlight.
Traditionally, unmerchantable trees in a stand that was being clearcut would be felled or killed standing. Only desirable seedlings and saplings (advance regeneration) would be left to grow. Today, however, retaining scattered trees or patches inside clearcuts is becoming more common. Residual trees and patches provide vertical habitat for some wildlife species, particularly raptors, which use the residual trees as perch sites. Residual trees also provide some age, size, and perhaps species diversity and may improve the visual quality of a clearcut. On the other hand, residual trees may be subject to wind damage and can interfere with the regeneration of desirable species that do not tolerate shade. For these reasons, residual trees often are left in patches rather than distributed uniformly throughout the clearcut. Clearcuts typically are larger than two acres, but vary greatly in size and shape.
As in all regeneration systems, sources of regeneration must be determined before harvesting, but they may include seedlings already present before the harvest (advance regeneration), natural seed on the forest floor or on tree branches at the time of harvest, natural seed produced by adjacent stands, direct seeding, replanting, or stump sprouts and root suckers sprouting after harvest.
Clearcutting is not appropriate where the removal of a mature overstory would allow the water table to rise and inhibit the regeneration of a new stand.
Figure 4-7. Clearcutting system.