14 l". S. DEPARTMENT OF AGRICULTURE BULLETIN NO. 484. 



Blue beech, choke cherry, wild red cherry, hop hornbeam, and 

 sassafras have no particular commercial value, and the elimination 

 of these species from stands would afford some degree of protection. 



Black cherry has considerable commercial value, but occurs very 

 scatteringly. As it is not a favored food, it may well be left in view 

 of its value. American elm and slippery elm also occur as scattered 

 trees. Their value is less than black cherry, but they might well 

 be left. Cottonwood, bitternut hickory, black gum, silver maple, 

 and silver poplar if found might well be eliminated from most 

 stands. Such an elimination would help to reduce the complexity 

 of stands and would serve as a protective measure. 



The remaining species of this class, black and yellow birch, mocker- 

 nut, pignut and shagbark hickories, and red and sugar maple, can 

 be grown in comparative safety. In any process of gradual trans- 

 formation these species should be retained in preference to the trees 

 of Class I. 



Class IV (p. 9) is composed of trees on which the gipsy moth 

 does not feed, or if it does, the amount is so slight as to be entirely 

 negligible. Stands composed of trees of this class alone, or combined 

 with the trees of Class II, need cause no anxiety whatever as far 

 as gipsy-moth attack is concerned. Some of the species of this 

 class are of rare occurrence, some require peculiar conditions for 

 their development, and some have little or no commercial value. 

 Arborvita?, black ash, and white cedar require very moist situations 

 and usually occur in or near swamps. Butternut, red cedar, locust, 

 honey locust, and sycamore all require a large amount of light. The 

 red ash, hackberry, American holly, red mulberry, tulip, and black 

 walnut are of rare and local occurrence, for which reason they can 

 not be depended upon to supply any large commercial demand. 

 Flowering dogwood, mountain laurel, mountain maple, striped 

 maple, and sheepberry have little or no commercial value locally. 

 The white ash has a high commercial value, but should be confined 

 to the best forest soils. 



In general, it may be said that stands containing only trees of 

 Classes II, III, and IV will suffer but slight damage from gipsy- 

 moth attack. The number of Class I trees would be tremendously 

 reduced if the worthless species were replaced by suitable trees and 

 the remainder were confined to the best sites, as is necessary if they 

 are to be grown at all profitably. 



Any plan for the removal of trees must provide for their replace- 

 ment with more desirable ones. All trees may be removed in one 

 operation and replaced in another, or the transformation may be 

 gradual. There are many conditions which influence the methods 

 to lie employed, and these vary greatly among different stands. It 

 is hoped that the experiments now in operation will provide a basis 



