ASPEX AS A TEMPORARY FOREST TYPE 



By Frederick S. Baker 



Forest Examiner, Utah Experiment Station, Bphraim, Utah 



An article by Mr. Fetherolf^ has lately appeared, which presents 

 very clearly the arguments for considering aspen as a permanent type 

 in the Great Basin region. Since, however, the article by Sampson- 

 mentioned only the finding of coniferous charcoal in a pure aspen 

 stand as an evidence of the essential instability of the local aspen, it 

 may perhaps be well to sum up all the evidence showing the temporary 

 nature of the aspen, for the question of its permanence is of great im- 

 portance in this region. 



It must be admitted at the outset that the aspen stands of the Great 

 Basin are certainly not ephemeral, but have probably existed much as 

 they are now for many generations and will doubtless last for many 

 more. Accordingly they have the appearance of permanence. In 

 Colorado and New Mexico, when conditions are similar, the temporary 

 nature of the aspen stands is not questioned, because the coniferous 

 climax is generally further advanced, and there is not even an appear- 

 ance of stability or even of long duration. Duration, however, is no 

 criterion of true stability.^ 



As defined by the Forest Service, a permanent or climax type is "a 

 forest type which will eventually take possession of and perpetuate 

 itself on any given area if natural conditions are undisturbed."* 



Therefore if aspen is giving way to conifers at all within its "perma- 

 nent" range, it is essentially transitory and a subclimax stage in the 

 succession. Fetherolf holds, however, "that there is no conifer in the 

 district with exactly the same requirements and qualities as aspen ; 

 hence there is left a strip or belt, as it were, in which no native conifer 

 can replace it, with or without the help of fire, just as there is a belt 

 in which tree species cannot compete with sagebrush, with Engelmann 



^Fetherolf, James M. : "Aspen as a Permanent Forest Type." Journal ot^ 

 Forestry, 15, 757-760, October, 1917. 



"Sampson, A. W. : 'The Stability of Aspen as a Type." Proceedings of tlir 

 Society of American Foresters. Vol. 11, 86, January, 1916. 



^ Clements, Frederic E. : "Plant Succession." Pub. 242, p. 105, Carnegie In- 

 stitution, Washington, 1916. 



* "Instructions for Making Timber Surveys in the National Forests." Forest 

 Service, U. S. Department of Agriculture, 1917. 



294 



