FOREST DEMANDS 33 



tility by the growth and removal of crops and by erosion. 

 If the forest has been growing long enough this decaying 

 matter will be found mixed with the earth to quite a depth, 

 changing it from barrenness into fertility and giving to it 

 a porous character and a darker color. Not only does it add 

 valuable chemical constituents to the soil, but the decaying 

 vegetable matter acts mechanically in keeping the soil loose. 



The importance of maintaining a suitable forest floor 

 cannot be too strenuously urged. When not amply pro- 

 vided, the trees suffer, in part through lack of a continuous 

 supply of moisture which is secured by its presence, and in 

 part through failure to receive the elements of fertility 

 which the leaves may secure from the atmosphere ; and the 

 result of a failure to maintain this ground cover is always 

 manifest in the slow growth of the trees of the forest. A 

 typical productive forest is one where the crowns of the 

 trees practically shut out the sunlight and where the ripened 

 foliage, cast-off bark, and decaying wood so completely 

 cover the ground as to prevent a rapid run-off of the water 

 that may reach there, retaining a portion which, for a while, 

 will supply the roots of the trees that are near the surface, 

 and also prevent the rapid evaporation which would occur 

 were not such covering present. The necessity for preserving 

 the forest floor intact was experimentally learned in Europe 

 some time ago where the freshly fallen and decaying leaves, 

 bark, and wood were, by permission, removed from the 

 forests by the peasants. It was discovered in due time 

 that the forest-growth was severely interfered with through 

 such removal, and it was prohibited. Experience proves it 

 is necessary to secure a complete covering of the ground by 

 the foliage as early as possible in the life of a newly planted 

 forest in order to prevent evaporation of moisture, and to 

 hasten the time when the cast-off leaves, bark, and twigs 

 will furnish the greatly needed protection for the ground. 

 This, as well as to secure a growth free from limbs, ren- 

 ders close planting necessary. 



The Forest Crown. While the forest floor is important, 



