Hill: Penobscot Vegetation 325 



tion forest is forced, because of the altitude, to give way to 

 a forest of the northeastern conifer type; and this in turn, 

 on the highest summits, may even yield its place to alpine 

 vegetation. 



From these few cases it can be seen that the limits of the 

 forest regions outlined above are not hard and fast and 

 there is bound to be overlapping and an intermingling of 

 various types. Such conditions are fairly local, however, 

 and in general the vegetation in any given place may readily 

 be assigned to one or another of the above formations. 



The Penobscot Bay region of Maine lies within the Ca- 

 nadian Transition zone of the Transition Forest region. 

 Its climax forest is that characteristic of the larger area — 

 a mixed deciduous coniferous forest of sugar maple, beech, 

 hemlock, yellow birch, balsam fir and spruce. The nature 

 of this regional climax association-type, the climax forest, 

 as it occurs in Cape Breton, and the successions which lead 

 to it have been described in detail by Nichols (23) and need 

 not be discussed here. Consequently we may proceed to a 

 description of the regional climax as it occurs in the Penob- 

 scot Bay region. 



III. THE CLIMAX FOREST OF THE PENOBSCOT 

 BAY REGION 



In the Penobscot Bay region the nature of the forest cov- 

 ering varies greatly and it is at first difficult to determine 

 which of the several common types of woodland represents 

 the actual regional climax association-type. On the islands 

 and the outer portions of the mainland the prevailing ap- 

 pearance of the forests is coniferous, and it is only when we 

 go back from the exposed shores to the more sheltered lo- 

 calities that we find deciduous trees appearing. Even here, 

 however, the influence of various disturbing factors has so 

 altered the nature of the vegetation that the cases where the 

 deciduous trees of the regional climax predominate are com- 



