11 



adjoining rows of Norway spruce, although the latter are planted 

 five years earlier. 



Combination No. 4. Rows 1 and 9, white cedar; rows 2 and 8, Nor- 

 way spruce; rows 3, 4, 5, 6 and 7, cottonwood. 



The evergreens on each flank of the shelterbelt will give efficient 

 protection against the wind close to the ground and, at the same 

 time, will give a pleasing effect to the windbreak both in summer 

 and winter time. The interior of the plantation will, in a few years, 

 not only break the force of the wind at some distance from the 

 ground, but also be a profitable source of saw timber or fuel. 



Combination No. 5. Row 1, white pine; row 2, white cedar; row 3, 

 white spruce; rows 4, 5 and 6, red cedar;* row 7, Jack pine; row 8, 

 western yellow pine; row 9, European larch. 



The above combination makes an effective shelterbelt of coniferous 

 species. The larch trees in row 9 shed their leaves during the winter. 



VARIATIONS IN THE METHOD 



It will seldom happen that the plan illustrated under this method 

 will exactly fit conditions found in other shelterbelts. The method 

 should be considered as suggestive and altered to suit local condi- 

 tions. In the case of a shelterbelt which has only three or four rows, 

 it would no doubt be preferable to use the system of regeneration 

 from one side, taking out one row at each period instead of two rows. 

 In the case of a plantation much wider than the one illustrated, it 

 might be preferable to take two rows of trees at a time from each 

 side instead of one row. There is no necessity of adhering to a 

 uniform period of five years between cuttings. This may be either 

 lengthened or shortened to suit convenience or necessity. On the other 

 hand, a plan should be prepared and the work should follow a definite 

 schedule or the regeneration will unquestionably prove a failure. 



REGENERATION BY CLEAR-CUTTING 



The method of clear-cutting is only employed when the windbreak 

 can be dispensed with while the new stand of trees is growing, or 

 where the old timber is in such poor condition that it must be re- 

 newed at once. Under such conditions, it is advisable either to cut 

 everything on the plantation or to leave only a row or two to give 

 some protection for a few years. 



Under this system it is advisable, where conditions will permit, to 

 leave two rows of the old trees after the first cutting, these rows to 

 be removed during the second and third steps, respectively, in the 

 regeneration process. (See figs. 11, 12, 13 and 14.) 



The system has several advantages. In cases where the old planta- 

 tion is to be cut into lumber (cottonwood for example), the trees 

 can be sawed at a minimum cost, since most of the plantation is 

 removed at one time. In addition, by removing practically all of 

 the stand at once and replanting, there is no damage to the new 

 stand of trees. On the other hand, where the timber is to be used 

 for fence posts and fuel, it very frequently happens that there is not 



*Red cedar should not be planted in the vicinity of apple trees. 



