222 FORESTRY IN NEW ENGLAND 



even though they may be above the hmit in diameter. On the 

 other hand, injured or suppressed trees frequently are seen, be- 

 low the limit in size, which are unthrifty and growing very 

 slowly if at all. Such unproductive trees ought to be cut, what- 

 ever their size, unless needed to scatter seed. 



The diameter hmit is thus "elastic," permitting the cutting 

 of some trees above and some below the limit. 



Where the forest is of the typical uneven-aged form it will be 

 possible to return to the sarhe areas and cut again after an 

 interval of ten to thirty years; the interval depending on the 

 amount of the first cut. 



A difficulty often met with in handling this type, as well as the 

 other spruce types, is the presence of balsam. This tree repro- 

 duces so well that it may become a strong competitor with the 

 spruce. On account of its lower value for lumber and pulpwood 

 it should be discriminated against in favor of the spruce.^ Where 

 the cutting is made on the selection system this discrimination 

 may be effected by cutting balsam to a lower diameter limit than 

 spruce. This limit should be as low as the market conditions on 

 any given tract allow. 



Swamp. — The method of handling this type is the same as 

 for the spruce flats. Wherever danger from windfall is great 

 (as is the case over a great part of the swamp type) , or occasion- 

 ally where a dense, nearly even-aged growth occurs, the stand 

 must be cut nearly clear, making provision for clumps of seed 

 trees, and where the stand is comparatively safe from wind the 

 selection system may be used. In a great many instances repro- 

 duction will be found already started before the cutting is made. 

 Here, even if the stand is cut clear, a good second crop will be 

 insured without leaving trees for seed. 



From one hundred to two hundred years, depending on the 

 quality of the site, are needed to produce yields of saw timber 

 on the swamp, spruce slope and flat types. 



^ The rapid growth of the balsam in part compensates for its lower value. 

 Eventually, as the market for bajsam becomes better, it may merit the same or even 

 greater attention than spruce. 



