RENEWING THE SHELTERBELT 



BY G. B. MACDONALD 



In removing the old decaying shelter-belt and replacing it with 

 younger and better trees, it is not necessary to lose its protective value 

 during the process. By following any one of the methods described 

 in this circular the old stand of trees may be cut out and a new 

 stand of the same or some other species secured while keeping the 

 shelterbelt in a more or less effective condition. 



On many farms in Iowa there is need of renewing the old shelter- 

 belts. They were planted in the early days mainly for protection and 

 and were made up of quick-growing, short-lived trees, such as the 

 soft maple, cottonwood, willow and boxelder, having been planted 

 heavily in the central and northern sections of the state. Some of 

 these shelterbelts have yielded good returns in fuel and lumber in 

 addition to affording protection to farm buildings. Others, through 

 the trampling of stock and other causes, have yielded only small 

 returns in wood products and only a little more in protection. Most 

 of these short-lived groves which are still uncut are in various stages 

 of decay and in many instances should be replaced with new stands of 

 of longer lived species. 



Five different methods for renewing shelterbelts in Iowa are pre-.. 

 sented in this circular: By renewing from one side; by renewing 

 from two sides; by renewing by clear cutting; by renewing in alter- 

 nate rows; by renewing by underplanting. Each method is illus- 

 trated with drawings which explain how the work is carried on for a 

 shelterbelt of average size. Whatever system is used must be so 

 adapted that it will meet the local conditions found in the shelterbelt 

 that is to be renewed. 



REGENERATION FROM ONE SIDE 



In this method the object is to replace the present stand of trees 

 gradually without losing much of the grove's protection value. If 

 the grove is so old or in such poor condition that it will not hold 

 together during the 15-year period required for regeneration, another 

 system should be used which will take a shorter time. 



METHOD OF REMOVING THE OLD TREES 



Figures 1 to 5 show how the cuttings should proceed. In the case 

 illustrated, it is assumed that the plantation is composed of 9 rows 

 and that the trees will last at least 15 years longer. The rows run east 

 and west and the grove is situated just to the north of the farm 

 Buildings. 



First Step: During the winter or early spring remove all of the 

 trees in the two south rows (8 and 9), leaving seven rows of trees 

 for protection for the farm buildings. During the spring the blank 

 rows should be planted up, preferably to one of the evergreen species 

 mentioned later. The two new rows of trees will receive an abundance 

 of light from the top and south side and also will be protected from 

 wind damage by the old trees, which will insure a good growth. The 

 new rows should be fully protected from stock and surface fires. 

 Cultivation for several years will keep out weeds and grass and 

 will increase the rate of growth. 



Second Step: Five years from the time the two south rows are 

 removed, cut out the next two (6 and 7) and replant in much the 

 same manner as the first two. Great care should be exercised in 

 felling the large trees so as not to damage the newly planted rows. 

 At this time also replant the fail spots in rows 8 and 9. 



