20 W00DL0T FORESTRY. 



easily managed because they contain but one, or, at the most, 

 a few, species. In any hardwood forest, however, trees of widely 

 varying light requirement are found. Pitch pine, red cedar, grey 

 birch and tulip poplar are some of our most intolerant trees; 

 black oak, red oak, white oak and basswood are more or less 

 tolerant, while beech and sugar maple are very tolerant. 



One intending to cultivate a forest should study the light re- 

 quirements of each species represented, and by proper and timely 

 thinnings give each tree the light it needs — not too much, for it 

 is easily possible to develop oversized crowns and to waste the 

 humus and foster weeds on the forest floor. Most trees need 

 some shade protection in early life, as direct sunlight frequently 

 causes the tender plants to dry out. Once fully established, how- 

 ever, any tree will make a more rapid growth in full sunlight 

 than elsewhere. 



Soil. — Each tree species grows best in some particular kind 

 of soil, yet, other things being equal, most trees will live in any 

 soil except the most impoverished. Trees even in the forest 

 often become established in places entirely unsuited for them. 

 Some species, like the hickories and oaks, have deep root sys- 

 tems, and consequently require a deep soil ; others, like the hem- 

 lock and spruce, have shallow root systems, and often will grow 

 in a few inches of soil on the face of a solid rock. In improv- 

 ing a forest the trees should be studied with reference to their 

 soil requirements, and an attempt made to bring about an ad- 

 justment by encouraging those which seem well satisfied. In 

 planting new forests the most suitable trees for a given locality 

 can always be found, but in the case of old forests, it is neces- 

 sary to make the best of the trees which are already on the 

 ground. 



Humus. — The humus which forms on the forest floor from 

 the decay of leaves and other litter is of value to the trees as 

 fertilizer, as a mulch to prevent the evaporation of moisture 

 from the soil, and as a medium through which the air may 

 reach the roots. The forest soil improves year by year as the 

 humus enters into it; it is, therefore, important to preserve it. 

 This can be done by keeping a moderate amount of shade. Too 



