THE NORTH TEMTERATK ZONE 89 



genus mainly confined to the tropics and to the temperate regions 



of the southern hemisphere. 



The forests of New Brunswick and Nova Scotia 1 are of two 

 types, one in which conifers predominate, and which approaches 

 the sub-arctic forest, the other mainly composed of deciduous 

 species. The latter occupies the best soils, and its most abundant 

 trees are sugar maple and paper birch, with an admixture of red 

 spruce and balsam fir, with occasionally white pine. In some areas 

 beeches are the prevailing trees. 



Recently, attention has been called to the occurrence in certain 

 isolated areas in eastern Canada of many plants unknown else- 

 where in eastern America, but which are identical with or closely 

 related to species of the Rocky Mountains and Pacific Coast. 

 These western species are especially abundant in the Gaspe 

 Peninsula at the mouth of the St. Lawrence, and on the Long 

 Range in Western Newfoundland. 



Fernald 2 has shown that the areas occupied b}^ these far- 

 western plants have apparently entirely escaped glaciation and 

 that these plants are probably relics of wide-spread pre-glacial 

 species which were destroyed elsewhere in eastern America by 

 the great ice-sheet which covered the rest of the country. 



Throughout northern New England, e. g., Maine, Northern 

 Vermont, and New Hampshire, the forest is much the same as 

 in New Brunswick. Red spruce is the most abundant species, 

 together with white pine and balsam fir. Beech and sugar maple 

 also occur, but less abundantly than the conifers. In the more 

 southerly areas of the coniferous forest, black spruce is more 

 abundant, and white cedar {Thuja occidental is) and hemlock occur, 

 as well as various deciduous trees. 



The conifers are more abundant at higher elevations, while 

 at the base of the mountains, especially in the better soils, de- 

 ciduous trees become dominant, and there is a transition to the 

 hard-wood forests characteristic of southern New England. Sugar 

 maple, beech, and yellow birch (Betula Ivied) are the commonest 

 trees, but oaks, elms, and other common New England species 

 begin to appear. 



1 HarshberKor, J. W. f Phytngcogrnphic Survey of North America. Die Vbgata- 

 tion der Erde, XIII, pp. .)<» 1-370, 1911. 



2 Fernald M. L., Persistence of Plants in Ungladated Arms of />'"/•<.// North 

 America, Mem. Amer. Acad, of Arts and Science, Vol. XV, No. Ill, 11)25. 



