The major tree disease in the coastal zone is the blister rust which occurs 

 when white pine is grown near Ribes species, such as currants or gooseberries. 

 The fungus grows through the needle or new shoot into the branch and from 

 there into the trunk where it produces a girdling, killing canker. Orange 

 blisters filled with spores appear on these cankers in the spring and spores 

 are liberated when the blisters break. The spores then infect Ribes leaves 

 and the cycle begins again. 



White pine should not be planted in an area where Ribes grow unless the Ribes 

 bushes are removed from the planting site and from an area 900 feet (273 m) 

 wide around it. Ribes should be removed in stands of white pine where blister 

 rust occurs. Losses in infected stands can be minimized by removing stem- 

 cankered trees and pruning the others to reduce the possibility of the rust 

 reaching the trunk through one or more lower branches. 



FUELW00D 



Recent price increases and scarcity of fuel oil has stirred interest in 

 heating with wood. A 1978 survey by the Maine Audubon Society revealed that 

 46% of Maine's households are currently heating entirely or partially with 

 wood and the average annual consumption of wood per household was 3.6 cords. 

 This use of wood for heating represents a net increase in the State's total 

 wood consumption. 



Species Used 



The species most used for heating are those with the highest BTU values, such 

 as oak and maple (table 19-7). The species are present in all of the forest 

 types previously described, but they are most indigenous to the northern 

 hardwood type. Silviculturally , the ideal way to produce fuelwood is by 

 selectively thinning hardwood stands. This method, when properly applied 

 throughout the life of the stand, will yield adequate amounts of fuelwood and 

 permit the most valuable species in a stand to grow rapidly throughout their 

 lives. Removal of less valuable competing trees enables the stand to 

 ultimately produce large, high quality trees that can be sold at rotation age 

 for veneer, sawlogs, and other valuable products. 



The monetary value of the species in a stand must be known before thinning can 

 begin (table 19-8). Sugar maple, white ash, yellow birch, and white birch, 

 usually, are more valuable than red maple, beech, and aspen. The higher- 

 valued species should be favored to remain uncut in the stands. 



Silvicultural Methods 



Thinnings should begin as early as possible so that the benefits of repeated 

 thinnings may be gained. The best time to begin thinning a hardwood stand is 

 when the trees average 4 to 10 inches (10 to 25 cm) in dbh. Trees of this 

 size class, commonly referred to as poles, respond rapidly to thinning because 

 intense competition from surrounding trees has begun to slow their growth. 

 Even larger trees, averaging 10 to 12 inches (25 to 50 cm) dbh, should 

 sometimes be thinned. These hardwood stands are approaching commercial 

 sawtimber size and some of the high quality thinned trees can probably be sold 

 as sawlogs. 



19-22 



