836 JOURNAL OF 1-ORESTRV 



Distribution of Age Classes. — The cedar association seems to be 

 even-aged, though we would expect the contrary on account of the 

 shade-enduring quahties of cedar. Its shade endurance is considerably 

 less than that of spruce, but almost if not quite equal to that of fir and 

 considerably greater than that of white pine. It may be, therefore, 

 that the even-aged character of the stands on Mt. Desert is due largely 

 to their youth, and that if undisturbed for a long while they would 

 become more or less uneven-aged. 



Reproduction. — The reproduction in many parts of the cedar asso- 

 ciation appears to be predominantly fir. This is because fir is the most 

 conspicuous growth among the large seedlings up to about 2 or 3 feet 

 in height. Mixed with the fir there is much cedar and some spruce ; 

 among the smaller seedlings cedar generally predominates and fir is 

 almost lacking. It is probable that the fir will diminish greatly before 

 the present generation of cedar dies off, and that the next generation 

 will contain about as high a percentage of cedar as the present one. 

 Spruce is fairly abundant under the main canopy ; white pine is of im- 

 portance only in the larger openings and where the stand has been 

 destroyed by fire or injured by cutting. 



Pitch-pine Association 



The pitch-pine (Pinus rigida) association is generally composed of 

 pure pitch pine, though frequently it contains an admixture of red pine, 

 and less commonly of red pine and white pine. Sometimes we find a 

 mixed association of pitch pine and white pine, which, however, can 

 generally be classed as either pitch pine or white pine, according to the 

 one which predominates. On the steep, rocky slopes bearing both of 

 these pines we sometimes find cedar in the crevices, together with red 

 oak and red maple, and also occasional clumps of alder ; but ordinarily 

 cedar is not a common associate of pitch pine. 



The characteristic ground cover of the more open portions of the 

 pitch-pine associations is ground juniper (Juniperus conimimis) , which 

 often forms dense mats between the pines. The more nearly fully 

 stocked stands are undergrown thickly with huckleberry (Gaylussacia 

 baccata). Among the first plants to start on the rocks between the 

 pines are blueberry (Vaccinium pennsylvanicum) and the attractive 

 little three-toothed cinquefoil (Sibbaldiopsis tridentata) , which in the 

 autumn aids in giving a beauty of coloring almost unsurpassed. Braken 

 fern, partridge berry (Mitchella rcpens), and wintergreen {Gaultheria 

 procumbens) are among the other plants common to this association. 



Occurrence. — The pitch pine is without doubt the most xerophytic 



