STRUCTURE AND REQUIREMENTS OF TREES 113 



of sand and rock and of vegetable matter called humus. 

 A tree will require a certain soil, and unsuitable soils can 



Fig. 90. — A Tree in the Open. Note the full development of the wide 

 crown with branches starting near the ground. The tree is the 

 European larch. 



be very often modified to suit the needs of the tree. A 

 deep, moderately loose, sandy loam, however, which is 



