VEGETATION MANAGEMENT — EGLER 321 



SUMMARY 



Vegetation management, a synthetic field involving basic sciences 

 as well as forestry, range management, wildlife management, and 

 other branches of land management, has recently been applied to 

 roadsides and rights-of-way. The rights-of-way include electric- 

 power transmission and distribution lines, telephone lines, pipelines, 

 railroad rights-of-way, and roadways, and in the aggregate repre- 

 sent a large acreage. These lands comprise a series of narrow belts, 

 each with its different demands and tolerances, varying from complete 

 bareness, as on rail ballast, to tall shrubs on the sides of power lines. 

 In addition to the direct importance of these lands for transportation 

 of men, materials, and power, they are of great public interest and 

 are important in the national economy. Factors involved in maintain- 

 ing such areas include potential fire hazards (such as flammable dry 

 grasses), landscaping with ornamental shrubs, control of undesirable 

 plants, and the preservation of wildlife habitats for game and small 

 birds. 



The control of vegetation with herbicide sprays is being studied. 

 The chemicals now mostly used are esters of 2, 4-D and 2, 4, 5-T and, 

 to a lesser extent, ammonium sulfamate. These are generally applied 

 as a summer-foliage blanket spray, using knapsack sprayers. This 

 technique has been heavily exploited by many chemical manufacturers 

 and spraying contractors to produce grasslands. The grasslands, 

 attractive in superficial appearance, are open to invasion by certain 

 tree species, are frequently a fire hazard, are relative deserts for 

 wildlife, and are devoid of ornamental shrubs and wildflowers. The 

 technique of selective basal spraying is usually preferable, and results 

 in a "shrubland" composed of shrubs, forbs, and grass. Such vegeta- 

 tion resists tree-seedling invasion, is less of a fire hazard, and has 

 optimum value for wildlife and the ornamental plants naturally 

 occurring. 



The vegetation development refers to the orderly succession of 

 vegetation types on land from which the original vegetation has been 

 removed. On abandoned agricultural lands, this development com- 

 prises a succession from annual weeds, through grasslands, forblands, 

 shrublands, and finally forests. The interpretation of this develop- 

 ment has usually been in terms of a succession of invading "relays," 

 each succeeding another in one community. Recent investigations 

 show that the initial floristic composition is of major importance in 

 that most of the trees and shrubs entered in a very early stage of de- 

 velopment, and only assumed physiognomic importance at a later 

 time. Such conditions are of considerable economic value, for un- 

 wanted trees of this category do not reinvade, once they are root- 

 killed by herbicides. 



