III. 

 DIRECT RESULTS OF WINDBREAK PLANTING TIMBER YIELDS. 



RELATION OF WINDBREAK FORMATION TO QUALITY 

 PRODUCTION. 



Before deciding what is the best form for a windbreak, the actual 

 timber value of the available species, and the comparative value of 

 the timber produced in single rows, in belts, and in wider tracts 

 should be carefully measured. A large number of estimates of the 

 products of different species under various conditions have been 

 made with such comparisons in view. 



Quality production in the case of the best forest trees depends 

 primarily upon the length of rotation or length of time taken to 

 mature the forest crop. In the production of any forest crop a point 

 is sooner or later reached where the interest on the investment 

 becomes greater than the annual increase in value. This stage, 

 which is known as the " financial rotation/' is often reached before 

 the forest has reached its greatest value, especially with species whose 

 value is dependent on the large size and clear quality of the logs. 

 The financial rotation is, of course, reached earliest when the interest 

 on money is high. 



The measurements of indirect benefits through protection must 

 have an important bearing upon the profits from forest planting, and 

 especially upon the growing of valuable forest products in long rota- 

 tions. If the indirect benefits pay the first cost of planting, or at 

 least the interest thereon, an important item of economy is added to 

 the management of woodlots. 



The method of planting whether in rows, belts, or groves will 

 have a strong influence on the quality and value of the products. 

 Trees in rows, like trees standing alone in open fields, will put a large 

 amount of their growing power into branches. Trees in belts may 

 grow in somewhat better form than those, in rows, but if a belt is 

 composed of only two or three rows the trees tend decidedly to spread 

 in both directions. This tendency results in the production of large 

 branches on one side, and frequently of stems which are bent, espe- 

 cially at the base of the tree, where the most valuable timber might 

 be produced. Trees in a grove or forest put most of their growth 

 into the bole; their branches are small and gradually drop off from 

 the base of the tree. 



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