Weir: Altitudinal Range of Forest Fungi 



5 



The limber pine (Pinus flexilis James) is also a timber line tree 

 in several regions visited, as is also the alpine larch (Larix 

 lyallii Pari.). Other trees reaching well up into the subalpine 

 zone are lodgepole pine (Pinus contorta Loud.), Engelmann 

 spruce (Picea engelmanni Engelm.), and Douglas fir (Pseudo- 

 tsuga taxifolia (Lam.) Britton), the latter often assuming most 

 peculiar and grotesque shapes. 



Although most of the higher elevations visited represent the 

 timber line for the region, the fungi collected would be found at 

 a much greater elevation farther south, since the altitude of the 

 timber line varies with the latitude in that direction while the 

 reverse is true to the northward. Specimens of forest tree fungi 

 at hand from some of the mountain ranges to the south and 

 from northern Alaska show this to be true. 



Factors Governing the Altitudinal Range of Forest Fungi 



In the course of the collection of fungi on high mountains many 

 points of interest have been recorded. Certain species disappear 

 with increasing elevation, some are chiefly associated with par- 

 ticular forest zones, wl^ile others are more cosmopolitan and are 

 found in greater or less quantity at all elevations. Some species 

 always occur in greater or less quantity under all conditions pro- 

 vided their hosts are present. For example, Fomcs pini (Brot.) 

 Lloyd and Echinodontium tinctorium E. & E. are always found 

 to accompany their respective hosts to the absolute timber line. 

 Both species primarily belong to the lower forest zones. Tubeuf 1 

 reports the occurrence of Fomes pini on Pinus cembra in the 

 Bavarian Highlands at an elevation of 1700 m. (5610 feet). 



In ascending a high mountain it is soon noticed that the 

 number of fungous species, likewise their abundance, decreases 

 with increasing elevation. Barring the demands on moisture this 

 seems to be due to the influence of temperature. It is known 

 that there is a particular optimum temperature for spore germina- 

 tion about which many species seem to oscillate. This may vary 

 from the temperature at which the best mycelial growth of the 



1 Tubeuf, C. v. Notizen iiber die Vertikalverbreitung der Trametes pini 

 und ihr Vorkommen an Verschiedenen holzarten. Naturw. Zeitschr. f. Land- 

 u. Forstw. 4: pp. 96-100. 



