338 George E. Nichols, 



but only frequent cutting will prevent trees from eventually gain- 

 ing supremacy. The speed with which grassland may become 

 superseded by woodland is suggested by the conditions observed in 

 two quadrats (10 meters, 32.8 feet square), which were located 

 in fields that had been neglected for twelve or fifteen years. In 

 one case, counting only specimens which were more than a foot 

 high, there were ninety trees in the quadrat, ranging up to twelve 

 feet in height and thirteen years in age. Of these trees, thirty- 

 four were white spruce, twenty-seven balsam fir, twenty-seven 

 paper birch, and two white pine. In another similar quadrat 

 there were fully five hundred trees, dead or alive, ranging up to 

 fifteen feet in height and averaging between eight and fifteen 

 years in age. In this case, the trees without exception were 

 white spruce. These quadrats illustrate the varying composition 

 which an old field woodland may possess. In some cases there 

 will be nearly pure stands of white spruce, in others intimate 

 admixtures of this tree with black spruce, balsam fir, and paper 

 birch. In the vicinity of Baddeck, and in a few other localities 

 noted, the tamarack, in many cases, rivals the white spruce for 

 ihe position of prominence in abandoned pastures. The local 

 frequency of the tamarack, as already suggested, is attributable, 

 without much question, to soil conditions : indeed, it seems quite 

 possible that the local distribution of this tree might prove of 

 value as an indicator of the capabilities of land for crop pro- 

 duction. It seems quite probable that variations in the composi- 

 tion of old field woodlands can be correlated still further with 

 local differences in soil, etc., although, so far as the observations 

 of the writer have extended, the variations might well be 

 explained, in large measure at any rate, by the proximity of 

 seed trees and the fortuitous distribution of seed. 



The changes which accompany the development of woodlands 

 in old fields can best be brought out by a specific illustration : a 

 series of pastures along the Barrasois River which have been 

 abandoned at different dates. The vegetation of the pastures 

 themselves is essentially as described above. The pioneer trees are 

 mostly white spruce. These germinate prolifically, especially in 

 places where there is a carpet of Polytrichttm. The moss carpet 

 apparently furnishes an ideal seed bed, since in situations where 

 it is absent reproduction is noticeably sparser. As the spruces 

 mature, forming first a rather open grove (Fig. 36) and later 



