The criteria for wise removal of trees are not adhered to in the coastal zone. 

 Instead, a selection method known as diameter-limit harvesting is employed. 

 Under this method all trees over a specified minimum diameter are removed. 

 Diameter limits range from 8 to 15 inches (20 to 38 cm) for the spruces and 

 over 6 inches (15 cm) for balsam fir. This method of cutting is conducive to 

 future stand development and keeps the cost of harvesting reasonably low, 

 however, diameter-limit harvesting removes large vigorous trees and leaves 

 small, poor-risk and defective trees. In some areas too many trees per acre 

 are removed, while too few are removed in other areas. The overall effect of 

 the diameter-limit method is to lower the quality of the stand. The long-term 

 genetic makeup of the forest is also affected adversely since only the best 

 trees are removed with each cutting, and the poorer trees remain to disperse 

 seeds and repopulate the area. Positive responses to selection for several 

 traits have been shown for most tree species growing in the spruce-fir type 

 (Wright 1976). Negative responses due to diameter-limit cutting practices are 

 to be expected but no confirmed dysgenic effects (detrimental to the genetic 

 quality) have been shown to date in the coastal zone. Diameter-limit cutting 

 is also frequently applied to the northern hardwood and white pine-hemlock- 

 hardwood types under the guise of selective harvesting. 



Mana gement of even-aged stands . Development of highly mechanized 

 harvesting systems has prompted the use of even-aged stands in the management 

 of the spruce-fir type. Although various methods of establishing even-aged 

 forest stands have found application, the method most frequently used in the 

 characterization area is the Clearcutting method. In clearcutting, all trees 

 on an area are removed in one cutting, with subsequent regeneration being 

 obtained from seed disseminated by adjacent forest stands and/or by the trees 

 being removed in the harvesting operation. Different methods of clearcutting 

 are discussed in "White Pine-Hemlock-Hardwbod Forest Type." Cutting areas may 

 also be artificially regenerated by planting seedlings or sowing seed. 



It is difficult to characterize all of the clearcutting operations that are 

 presently taking place in or near the characterization area. A typical 

 operation would have these component parts: (1) mature trees are cut either 

 mechanically or by hand; (2) they are delimbed in the woods or are dragged to 

 the roadside and then delimbed; (3) a reproduction survey is performed on the 

 area and if adequate reproduction of desired species is expected to take 

 place, no additional reforestation steps are taken; if an adequate 

 reproduction is not expected, planting is done; (4) 2 to 3 years after 

 clearcutting, the area is aerially sprayed with herbicide to kill hardwoods, 

 raspberries, and other competing vegetative growth. 



Major ecological implications of clearcutting are as follows: 



1. The effect of mechanical harvesting on soil quality. Holman (1977) 

 found that no permanent compaction of soils was present in clearcut 

 areas as bulk densities returned to preharvest levels after one 

 complete overwintering period. The most compaction observed was on 

 skid trails that had been used in the summer. Several different 

 types of mechanical harvesting systems are currently in use in the 

 coastal zone, however, and different levels of compaction could be 

 expected with different systems. 



19-11 



10-80 



