﻿32 



BULLETIN 11, U. S. DEPARTMENT OF AGRICULTURE. 



Under this method the stand is cut to a rough diameter limit, either 

 because it does not actually pay to cut trees below that limit or 

 because it is wished to leave trees to form the basis for a second cut 

 10 to 20 years later. 



If, in pure well-stocked stands, a large number of trees remain 

 after lumbering by the diameter-limit method, excellent results will 

 often be had both in the growth of trees left and in the seeding of a 

 new stand, the cutting, in its effects, amounting to a modified form of 

 the method of successive thinnings. The chief drawback is that the 

 small-crowned overtopped trees, such as would be left under this 

 method, require a number of years to recover from suppression 

 before producing much seed; and, furthermore, a large proportion of 

 them usually die or are windthrown or broken within a few years 

 after lumbering, especially on dry and exposed situations. It some- 

 times happens, however, as shown in Table 25, that the area cut under 

 this method is immediately seeded up from seed produced by the 

 large-crowned trees removed at the cutting, or from seed trees left in 

 the vicinity of the area cut. Table 25 is a summary of the results 

 of cutting a half-acre plot in a 35-year-old fully stocked stand of 

 loblolly pine on fresh, sandy soil, to a diameter limit of 12 inches 

 breasthigh in the winter of 1904. The stand was measured in 1906, 

 and remeasured 4^ years later. It indicates what sometimes happens, 

 under favorable conditions, in cutting by the ordinary diameter-limit 

 method. (See Plate III.) 



Table 25. — Effect of a diameter-limit cutting on a half acre of even-aged, fully stocked 



loblolly pine 35 years old. 



TREES REMOVED, TREES DYING, AND GROWTH OF TREES REMAINING. 





Removed, 

 1904. 



Remaining. 



Died, 

 1906-1910. 



Increase 

 ( + ) or de- 





1906 



1910 



crease (— ) 

 in 4i years. 



Number of trees 



65 



13(12.8) 



70 

 1,638 

 8,450 



53 



8.4 



60 



493 



1,900 



44 

 9.1 

 60.3 

 475 

 2,400 



9 



7.9 

 60 

 69 

 270 



Per cent. 

 -17 





+ 7.7 





+ .05 





+ 3.7 





+26.3 







AMOUNT AND GROWTH OF LOBLOLLY-PINE REPRODUCTION ON THE HALF ACRE. 



Size. 



Number. 



1906 



to 2 feet in heigbt 



2 to 4 feet in height 



4 to 6 feet in height 



1 inch in diameter breasthigh . . 



2 inches in diameter breasthigh . 



3 inches in diameter breasthigh 



720 

 101 

 32 



125 

 203 

 214 

 62 



5 



