14 



Mycologia 



Summary 



Most forest fungi have a great altitudinal range, being found- 

 from sea level to the extreme limits of the timbered zones. 



Most of the common forest fungi are found at the highest 

 timbered zones but are not so abundant as at lower elevations. 



Certain of the more economic species predominate in particular 

 forest zones or types. 



Some species are strictly alpine in habit and are not found 

 below certain elevations and exhibit particular adaptation to 

 their environment. 



With increasing elevation the sporophores of certain fungi pre- 

 dominating in lower forest zones exhibit many changes in form, 

 structure, and in mode and place of attachment. The great varia - 

 tion in the temperature and moisture relation induced by the 

 diversity of high mountain regions may greatly influence the de- 

 velopment of the aerial parts of wood-destroying fungi but may 

 not materially influence their development within the substratum. 



The influence of high mountain conditions on the form and 

 structure of host plants in turn influence the growth of their 

 fungous parasites. 



Office of Investigations in Forest Pathology, 

 Bureau of Plant Industry, 

 Missoula, Montana. 



