1919] CURRENT LITERATURE 371 



characterized by long winters and short cool summers, the extremes of tem- 

 perature being modified by the close proximity of the ocean. A rainfall of 

 50 in. per year and frequency of fogs make the water supply sufficient for a 

 luxuriant vegetation, which has been carefully studied by Nichols.'' He finds 

 two climatic forest formations represented, the deciduous type upon the low- 

 lands which fringe the coast, and the coniferous type upon the granite uplands 

 which occupy the entire interior portion of the island. These are about 

 1000 ft. above sea level and form a slightly undulating glaciated surface. 



The lowlands show many associations depending upon the stage of develop- 

 ment attained, and these variations and the successive stages which have led 

 to their development are carefully discussed and the climax shown to be a 

 forest dominated by beech, sugar maple, and hemlock, together with small 

 quantities of Betula lutea, Picea canadensis, and Abies balsamea. The abundant 

 details of these studies cannot be noticed in a brief review, but two problems in 

 the relationship between the deciduous and evergreen elements of the vegetation 

 are decidedly interesting. It has been found that upon the destruction of the 

 deciduous forest by culling or burning it is succeeded by a coniferous stand 

 dominated by Abies balsama and Picea canadensis; and further that the climax 

 deciduous forest possesses a very considerable percentage of small Abies 

 balsamea which never seem to succeed in competition with the other tree 

 members of the association. Nichols presents evidence showing that the 

 balsam fir is fairly shade tolerant, and that its lack of success is due to its short 

 life, maturity being attained in about one century, and to its great susceptibility 

 to fungus diseases. 



It seems evident that the coniferous forest dominated by Abies and Picea 

 is the cHmatic rather than the edaphic climax of all portions of the island 

 exceeding 700 ft. in elevation. The factors which appear to differentiate the 

 climate of the uplands from that of the lowlands are the greater extremes of 

 temperature and the greater humidity due to fogs and low-hung clouds which 

 frequently envelop the more elevated areas. 



This upland forest is of decided importance in the production of pulp wood, 

 its contents being estimated at 12,000,000 cords. Upon the more exposed 

 parts of the uplands are developed "the barrens," closely resembUng the 

 tundras of the subarctic. The low vegetation of "the barrens" varies from a 

 degenerate coniferous forest of the Krummholz type, where the distorted trees 

 are limited in height to the thickness of the snow cover, to coniferous and 

 ericaceous heaths, and to bogs of varied character. These bogs occupy con- 

 siderable portions both of the lowlands and "the barrens," their most striking 

 form being the raised peat bogs of the latter region, which have received careful 

 attention, so that many problems connected with their development have been 

 elucidated. 



^ Nichols, Geo. E., The vegetation of northern Cape Breton Island, Nova Scotia. 

 Trans. Conn. Acad. 22:249-267. figs. 70. 1918. 



