350 GEOKGE E. NICHOLS 



THE SCHEME OF CLASSIFICATION IN PRACTICE 



Outline classification of the vegetation of northern Cape Breton 

 Island. The practical application of the classification of plant 

 communities according to the concepts enunciated in the fore- 

 going pages \\dll now be illustrated by a specific example. The 

 vegetation of the area selected has been under investigation 

 for four summers, and a full account of the writer's observations 

 and conclusions here is in the course of preparation. Northern 

 Cape Breton Hes in the transition zone between the two great 

 climatic formations of eastern North America: the deciduous 

 forest chmatic formation and the northeastern evergreen conifer- 

 ous forest climatic formation, and, owing largely to differences of 

 elevation, both of these are well developed, the former on the 

 lowlands and the latter on the highlands. The scheme adopted 

 in classifying the various edaphic formations which comprise 

 the deciduous forest chmatic formation here, is outUned below. 

 Such a scheme, it should be borne in mind, answers much the 

 same purpose in the realm of physiographic ecology as an analyt- 

 ical key in the realm of systematic botany. The classification 

 has been carried as far as the ecological genus, i.e., as far as 

 the group of associations which comprises an edaphic formation. 



The Vegetation of Northern Cape Breton 

 The deciduous forest climatic formation 



I. The regional climax association-type 

 II. The edaphic formation-complex of the region 



A. Primary formations of the xerarch successional series 

 1. The formation-types of ordinary uplands 



a. The association-complexes of exposed rock outcrops 



b. The association-complexes of talus 



c. The association-complexes of glacial drift 



2. The formation-types of uplands along streams 



a. The association-complexes of rock ravines 



b. The association-complexes of open valleys 



c. The association-complexes of boulder plains 



d. The association-complexes of flood plains 



3. The formation-types of uplands along the seacoast 



a. The association-complexes of sea-bluffs and headlands 



b. The association-complexes of shingle beaches 



c. The association-complexes of sandy beaches and dunes 



