340 Proceedings Portland Society Natural History 



pecially characteristic of the islands and seaward peninsulas 

 of the mainland, where it grows in the most exposed situa- 

 tions even on the very edges of the rocky shores (Figure 

 19), where it must be subjected not only to cold fogs but to 

 the constant drenching by wind swept spray as well. Many 

 of the smaller rocky islands have as their entire vegetation 

 a forest of this sort, which constitutes a physiographic cli- 

 max and seems likely to persist indefinitely unless condi- 

 tions are altered. The summits of the higher mountains, 

 such as Great Pond Mountain in Orland, Isle au Haut, and 

 Ragged and Megunticook Mountains among the Camden 

 Hills also have a coniferous forest of this type. 



Normally, however, this first rather xerophytic forest is 

 not at all permanent. The death of the older trees and 

 their removal, due to windfall, results in the admission of 

 more light to the forest floor and the consequent appearance 

 of a moss carpet. This in turn favors the coming in of 

 herbaceous plants and shrubs, and the better development 

 of seedlings. The suppressed little spruces, which were able 

 to tolerate the deep shade, now grow rapidly under the 

 stimulus of the renewed light. Reproduction, chiefly of bal~ 

 sam, takes place in these open places, and as is the case else- 

 where the rapidity with which this species grows makes up 

 for its lack of tolerance. As conditions become more and 

 more mesophytic and a larger amount of soil accumulates, 

 another type of coniferous forest (Figure 9) is gradually 

 developed in which balsam fir is nearly as prominent as the 

 red spruce, and other species are conspicuous members, 

 chiefly the paper birch, white spruce, mountain ash (Pyrus 

 americana), mountain maple, moosewood, alder (Abuts 

 crispa var. mollis), hobble bush, withe-rod (Viburnum cas- 

 sinoides ) and yew. The most conspicuous feature of these 

 woods is the profuse moss carpet, which comprises a great 

 number of species of both mosses and liverworts. Promi- 

 nent forms include: 



