66 BULLETIN 55, U. S. DEPARTMENT OF AGEICULTUKE. 



2, The same ground should not be logged too often; say, not oftener 

 than every 10 or 20 years. Frequent logging over the same area 

 prevents the firm establishment of 3^oung growth. 



3. Keep out fires from the logged-over areas. 



This system of gradual cutting, which may be called a selection 

 system in groups, is decidedly the most practical, simplest, and 

 safest so far as securing natural reproduction of spruce and balsam 

 is concerned. Under it, spruce reproduction is favored at the expense 

 of balsam, since the openings are small and the hght conditions 

 more favorable to spruce than to balsam. The greatest advantage 

 of the system, however, is the protection which it affords against 

 windfall — a very important consideration in all spruce cuttings. 



The system differs from the method of logging practiced 25 to 30 

 years ago only in that the trees are cut in small groups instead of 

 singly. Many of the old cuttings, when fires were kept out, have been 

 cut over for the second and third time. Experience shows that no 

 forest has ever been ruined by such a method of cutting. It is the 

 recent logging, which amounts to practically clear cutting, especially 

 when followed by fires, which has reduced large areas of timberland 

 to a state where artificial planting or sowing is the only means of 

 bringing them baqk to forest'. 



By clear cutting small groups, opportunity is afforded for utihzing 

 all the merchantable timber, especially if the openings are made in 

 the older and more mature stands. At the same time, forest con- 

 ditions are preserved which are favorable for natural reproduction. 

 The danger from windfall under this method is almost entirely 

 avoided. 



Cutting to a diameter limit. — Cutting in strips or selection cutting 

 in groups requires a careful selection of the logging areas and expert 

 technical knowledge. Wherever such knowledge can not be had, 

 light cutting over the entire logging area may roughly answer the 

 requirements of natural reproduction of both spruce and balsam fir. 

 The higher the diameter limit for both species the more favorable 

 will be the conditions for natural reproduction. The diameter limit 

 should be raised in thin stands and lowered in dense ones, the main 

 point being not to open the stand too heavily and destroy the con- 

 ditions under which natural reproduction takes place. Although by 

 cutting balsam fir to a lower diameter than spruce some advantage 

 may be given spruce in reseeding the ground, yet under such a rough 

 system it is difficult to control the conditions under wliich one or 

 the other species can best come up; the preponderance of spruce or 

 balsam fir in the future stand must therefore be left largely to chance. 



