HERMAN H. CHAPMAN 39 



is a temporary type only because reproduction occurs at 

 irregular intervals depending on accidental conditions, and 

 this reproduction may not be of the original species. 



The types which.,, are most truly temporary are those 

 formed by short lived; species with seeds wind blown or 

 carried by birds, and which cannot hold their own if any 

 other species can reach the same area with seeds. For 

 this reason cedar in old pastures or aspen stands on burned 

 lands are true temporary types. 



Types are of the greatest use to the forester. They in- 

 dicate the quality of the soil and the kind of wood materials 

 which it will produce, and determine the species of trees 

 which he should try to raise in the future. It is useless 

 to attempt to grow trees on any soil which is not suited 

 to the demands of that species, and there are always kinds 

 which are adapted to it, and will make as good growth 

 as the site permits. No greater fallacy exists than that 

 any tree found in a region can be successfully grown for 

 wood products on any site in the region. Mistakes can 

 be made which will not become evident for many years, 

 and the only sure guide for the forester in planting or man- 

 agement of forests is the evidence constantly before his 

 eyes of the natural types, representing the survival of 

 the fittest. From such types he can gain the knowledge 

 necessary to decide what trees to plant on vacant land, 

 or to recognize a purely temporary type, and know wheth- 

 er a better species might not grow there if given a chance. 

 For instance, white pine would ordinarily grow well in 

 old pastures, if planted there, when for lack of seed trees, 

 it might not be present at all under natural condi- 

 tions. 



The Basis for Distinguishing Types. Types, being the 

 result of a number of influences, are not usually bounded 

 by sharp lines, except where artificially produced as in 

 clearing. They grade into one another and their bounda- 

 ries are somewhat arbitrary. Nor is the composition of a 



