52 FOREST PLANTING. 



their early age have a dense foliage, that, with increased 

 age, is getting thinner, and such as preserve their dense 

 foliage. To the latter belong Firs, Beeches, Spruces, and 

 the Catalpa; to the former, Oaks, Birches, Pines, 

 Larches, Hickories. 



Valuable hints on mixed forest planting are given in 

 the Report of the Division of Forestry, published by the 

 Department of Agriculture at Washington, 1887, on 

 page 189. There we read : "After having determined 

 what kinds are desirable and suitable to be planted in a 

 given locality, the possibility of mixing two or more 

 kinds depends : 



(a) On their relative capacity for preserving or in- 

 creasing favorable soil conditions ; 



(b) On their relative dependence for development on 

 light or shade ; and 



(c) On their relative rate of height growth." 



As general rules for mixing are thereupon summed up 

 the following : 



1. The dominant species, i. e., the one that occupies 

 the greater part of the ground, must be one that im- 

 proves the soil conditions, generally a shady kind. 



2. Shade-enduring (i. e., densely foliaged) kinds may 

 be mixed together when the slower-growing kinds can be 

 protected or guarded against the overshading of the more 

 rapid grower, either by planting the slower grower first 

 or in greater numbers, or in larger specimens, or else by 

 cutting back the quicker-growing ones. 



3. Shade-enduring kinds may be mixed with light- 

 needing kinds, when the latter are either quicker growing 

 or are planted in advance of the former, or in larger 

 specimens. 



4. Thin foliaged kinds should not be planted in mix- 

 tures by themselves, except on very favorable soils, as in 

 river bottoms, marshy soil, etc., where no exhausting of 



