;344 Proceedings Portland Society Natural History 



(2) Lack of basic material. Such mineral soil as may 

 be present is derived from sterile acid granites, gneisses and 

 quartzites, and does not afford the requisite amount of basic 

 material necessary for most of the rich woods types. 



(3) Exposure. The proximity of the ocean with the 

 accompanying fogs and cold winds has the same limiting ef- 

 fect on the vegetation as increase in altitude or latitude, 

 resulting in a local climate within a larger climatic unit 

 area. 



These factors which prevent the development of the re- 

 gional climax are distinctly favorable for the coniferous 

 forest and this latter type is widespread in the coastal re- 

 gion, where it forms at once the most prominent and strik- 

 ing feature of the landscape. The dense stands of spruce 

 and fir, particularly on the islands, stand out in unexcelled 

 beauty against the sky and water, and their pyramid out- 

 line deservedly entitles the region to be known as "the coun- 

 try of the pointed firs." 



In a few instances there is developed in the Penobscot 

 Bay region an upland forest in which the white cedar (Thu- 

 ja occidentalis) is the predominant tree. This species is 

 more characteristic of the swam]) forests of the region, but 

 it occasionally is found occupying hollows and other rela- 

 tively moist sites on the uplands. The stands may be al- 

 most pure cedar, but usually considerable spruce and white 

 birch is present. In rare cases this forest is developed on 

 rocky ledges, usually of diorite, situated near the sea and 

 in areas where there is abundant moisture from higher up 

 on the slopes. It is an interesting fact that such stands 

 almost invariably occupy the seaward slopes of the moun- 

 tains and it is conceivable that the mountain summits inter- 

 cept the fogs, which blow in from the ocean at all seasons, 

 and precipitate them on these eastern slopes, thereby in- 

 creasing the atmospheric humidity and the general moisture 

 conditions. 



