; 
d 
: 
e. 
: 
4 
VOLUME LV NUMBER 1 
THE 
TOL ANICAL. (GAZETTE 
JANUARY 1913 
THE CLIMAX FOREST OF ISLE ROYALE, LAKE 
SUPERIOR, AND ITS DEVELOPMENT. I 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 165 
WILLIAM S. COOPER 
(WITH MAP AND FOURTEEN FIGURES) 
Introduction 
Eastern North America north of Florida and Mexico is divided 
into two great phytogeographic regions, the eastern deciduous 
forest and the northeastern. conifer forest. Im each of these a 
number of lines of succession may be traced, all those of a region 
leading to a certain forest type as the final or climax stage. This 
final type in its large features is determined by climate, and is 
much the same throughout the region which it dominates. In the 
eastern deciduous forest the climax type is made up of Acer sac- 
charum Marsh (sugar maple) and Fagus grandifolia Ehrh. (beech), 
with the addition of various other species in some portions of the 
country. The nature of the climax forest of the northeastern 
conifer region has not hitherto been determined. 
Isle Royale lies just within the limits of the northeastern conifer 
region, barely within, for one of the farthest outposts of the decidu- 
ous forest is located on its southwestern end, where there is a 
considerable area dominated by the sugar maple, in mixture with 
more northern trees. Except for the maple and a few of its com- 
panion species, the flora of Isle Royale belongs strictly to the north- 
eastern conifer region. 
