2 BOTANICAL GAZETTE [JANUARY 
The purpose of the present work was to determine the climax 
forest of Isle Royale, its composition and character, and to trace 
the various lines of succession leading to it. _ It is thus a successional 
study of a small component portion of the northeastern conifer 
forest. : 
At the beginning of the investigation Isle Royale was selected 
as a field of study because it shows transitional features between the 
two great forest regions, my original purpose being to devote 
particular attention to the relations between the conifers and the 
maple. Circumstances made it impossible to give adequate study 
to the region dominated by the latter, therefore the work developed 
into an investigation of the balsam-birch-spruce forest (the north- 
eastern climax) and its attendant successions. For a study of the 
northeastern conifer forest a more centrally located area might 
have been preferable; for instance, at some point midway between 
Lake Superior and James Bay. It will be shown, however, that 
Isle Royale affords a very fair sample of the forest growth of the 
northeastern region. It also possesses certain very important 
advantages which would be lacking in a more centrally located 
area. Because of its insular position the forest has been less liable 
to destruction by fire, and the many bays and channels separating 
various portions of the main island and the outlying islets have 
served as effective barriers against its spread. Though they have 
occurred many times during the island’s history, it is certain that 
fires have been far less frequent and destructive here than upon 
the mainland. The forest may thus be studied in a condition that 
is as near to being undisturbed as will be found anywhere. Com- 
parative freedom from the destructive agency of man is a second 
advantage. Again, the island has had a simple physiographic 
history during the present vegetative cycle, and thus the relation 
of vegetation to physiography may be the more readily made out. 
Further, the proximity of the lake shores permits the observation 
of the earliest stages in the establishment of vegetation upon the 
rock surfaces, these stages being frequently absent or poorly 
developed in an inland locality. Finally, the fact that the field 
of study is an island gives definiteness to the area covered by the 
investigation. 
