THE RED SPRUCE. 49 



lating or saw-toothed, like a series of wedges or triangles with their 

 bases on line. This modification is rather commonly used with 

 spruce abroad. 



Effectiveness in securing reproduction with the strip plan will 

 depend upon the width of the strips employed. Satisfactory restock- 

 ing of the cleared area can not be expected on a strip wider than twice 

 the height of the trees in the adjacent stand; not because of inabil- 

 ity to secure effective seed dispersal at even a great distance, but 

 because of the effect upon seed germination and growth. Too exten- 

 sive cutting will expose the soil to drying influences detrimental to 

 spruce reproduction and at the same time create a condition favor- 

 able to the development of hardwoods, raspberry, and other peren- 

 nials and weed growth in general. 



Satisfactory reproduction in the reserve strips must be secured as 

 advanced growth from seed trees standing on those strips, or the 

 cutting of the reserve strips must be delayed until the trees on the 

 strips first cleared are large enough to supply the necessary seed. A 

 spruce stand in which windfirmness has been especially developed by 

 periodic thinning from early youth may be reproduced by the shelter- 

 wood compartment method. Such stands, however, can hardly be 

 said to exist in this country at the present time. Thinnings of the 

 severity of shelter-wood cuttings are largely out of the question in the 

 previously unthinned stands of either virgin or old-field spruce which 

 it is desirable to manage under a system of clean cutting in strips. 



To insure an early second cut and prompt and effective regenera- 

 tion, alternate cut and uncut strips not over 75 feet in width should 

 be employed. By the adoption of strips of this width reproduction 

 would not only be reasonably assured to the cleared strips but the 

 side light and extra ventilation which would be let into the uncleared 

 strips would be sufficient to create a condition favorable to satisfac- 

 tory reproduction there also. For the dense, even-aged, old-field 

 stands, strips as narrow as 10 feet with 20-foot reserve strips inter- 

 vening have been recommended. 1 The final clearing of the area under 

 such a system should be possible within 10 or 15 years after the first 

 cut. This will enable the harvesting of a third or more of the crop at 

 one cut, The cost will of course be somewhat more than if wider 

 strips or clean cutting in a solid block were practiced. The yield and 

 operating cost per unit of area should not, however, be materially 

 different from that which would result from cutting to a diameter 

 limit of 14 inches, except that slightly greater expense would attach 

 to the handling and marketing of the smaller material which the clean 

 cuttings would yield. 



i " Forestry in New England," by R. C Hawley and A. F. Hawes, p. 226. 

 84949°— Bull. 544—17 4 



