we find Picea dominating in one place and Abies in another. 



At the present time the Krummholz forest covers the upper 

 slopes of the various spurs, a greater part of the "tableland," 

 practically all of the "saddle," and extends far up toward the 

 summits, scattered trees being noted within a hundred feet of the 

 top (Figs. 2, 3). It is then only a question of time when the 

 entire mountain, where physically possible, may be forest clad. 

 That is, this possibility is not climatically excluded but only 

 edaphically retarded. 



The composition of the Krummhols is most astonishing. 

 Associated with the Picea and Abies are Betula papyrifera cordi- 

 folia, Pyrus americana, and Amelanchier oligocarpa. On the 

 forest floor Cor mis canadensis, Chio genes serpylhfolia, Coptis 

 trifolia, Linrxea borealis, Maianthemum canadense, Clintonia 

 borealis, Trientalis americana, Oxalis acetosella, Gaultheria-pro- 

 cumbens, Moneses grandiflora, Lister a cordata, Aspidium spinu- 

 losum dilatatum, Streptopus roseus, Aster macrophyllus, Carex 

 trisperma, Hylocomium splendens, Hypnum crista-castrensis, H. 

 Schreberi, and Dicranum all abound and in rich profusion. 

 These forms, and many others which might be mentioned, are all 

 common to the climax mesophytic forest of the region. 

 Further, most of these forms are characteristic of the mesophytic 

 forest of low altitudes. It seems then that the Krummholz 

 forest is almost as mesophytic as the Picea-Abies combination of 

 the Great basin and surrounding country, which very evidently 

 is the climatic mesophytic forest of this district. The nature of 

 this forest will be referred to a later discussion. 



In other words, no true alpine conditions or climatic 

 timber lines exist upon Ktaadn. The first is probably excluded 

 by the excessive moisture, its happy distribution, and abundant 

 retention, making the alpine conditions quite mesophytic. ' The 

 so called timber line, a popular rather than scientific delimitation, 

 is purely physical and not a climatic demarkation. 



The conditions along the tension line between the Krummholz 

 and the Alpine-Tundra are very suggestive. As the forest 

 advances and takes possession of the mat, many forms are driven 

 out, presumably by light starvation. Other forms are better able 

 to adapt themselves and so remain as relicts of the Alpine mat. 



34 



