Fig. 6. At the beginning the two dhtside rows, 1 and 9, are cut out and re- 

 planted the same year with young trees of the new species. 



Fig. 7. After 5 years, rows 2 and 8 are cut out and planted with new trees; 

 the trees in rows 1 and 9 are 5 years old. 



At the beginning, rows 1 and 9 of the old plantation are cut out 

 and replanted to the new species. Five years later rows 2 and 8 are 

 taken out, and after another period of five years, rows 3 and 7 are 

 removed. At the last cutting, rows 4, 5 and 6 are replaced with 

 young trees. It will be seen that fair protection from the wind is 

 afforded by the old trees, even up to the last cutting, and by this time 

 some of the newly-planted trees should be sufficiently high to give 

 some protection. 



USE OF THE METHOD FOR DIFFERENT SHELTERBELTS 



This second method should be almost as successful in regenerating 

 short-lived shelterbelts of cottonwood, soft maple, willow and boxelder, 

 as the method of planting up from one side. There is one slight dis- 

 advantage; the new trees planted directly north of the old rows will 

 receive less light than those planted to the south, consequently, some 

 care should be exercised in the selection of species for planting. The 

 shading is most severe in the cases of soft maple and boxelder shelter- 

 belts, since the foliage of these trees is much more dense than that 

 of the cottonwood or willow. 



