HERMAN H. CHAPMAN 37 



safe to cut it for sprouts. The best season is from late 

 fall till before the growth starts in the spring. The stumps 

 should be cut low, with slanting surfaces, to prevent rapid 

 decay. A great many sprouts start, their number being 

 an indication of the vigor of 'the tree. In a few years these 

 are reduced by natural competition to 8 or 10, and only 

 two or three will mature as a rule. 



% Forest Types. To sum up, the composition of a forest 

 is determined by the conditions of heat, exposure, soil and 

 moisture; by the hereditary qualities of tree species which 

 enable them to compete for these sites, and by the de- 

 structive forces of nature and man combined, which modify 

 natural conditions. The accidental combinations of these 

 three elements give rise to the infinite variety which we 

 find in our woods. But as a rule in any given region, 

 the same set of conditions will produce the same kind of 

 forest. There will be certain characteristic associations 

 of species, which are able to grow together, or compete 

 with each other. These associations are known as forest 

 types, and are sometimes divided into permanent types 

 and temporary types. Permanent types are found in re- 

 gions where the forest is never destroyed violently by 

 fire, wind, insects, or lumbering, and where, during many 

 centuries, the struggle has gone on until only the most 

 enduring species, usually very tolerant, have survived. 

 The Adirondack hardwoods, of beech, hard maple, and scat- 

 tered spruce, are the best illustration. The forest floor is 

 covered with an accumulation of litter and humus some- 

 times two feet deep, showing entire absence of fires, and 

 these trees seldom blow over except singly here and there. 

 Starting with such a type we might construct a series, in 

 which accidental destruction played a stronger and strong- 

 er role until we come to types which are of such purely 

 temporary character that they are sure to be succeeded by 

 other species. Following the so-called permanent types, 

 come the types formed by most of the hardwoods, such as 



