116 College of Forestry 
being typically hardwood. In general, climatic factors ap- 
pear to control this broader aspect of distribution, but it 
should be noted that it is just in swamps and particularly 
in bogs where the northern coniferous element presses far- 
thest into the more austral zones A, B and C. The follow- 
ing types are suggested tentatively as being based on perhaps 
a too general and superficial survey im which secondary 
forest growth has been too largely represented. 
(1) Dominantly Coniferous Swamp forest. 
a. Balsam Swamp Forest and Balsam Flat. 
The stands of balsam forest on the built-wp and glacial- 
fill soils of the Adirondacks are of course one of the striking 
features of that well-known region. Zon,’ pages 4-6, de- 
scribes these two aspects of essentially swamp forest, giving 
particularly accurate and full percentage data as to the 
ground cover which is a key to the floristic relations. His 
bulletin may profitably be consulted in this and other con- 
nections having to do with the floristie relations of the Adi- 
rondack region as well as with environmental conditions. 
Note especially the map showing balsam distribution, page 3. 
b. Mixed Conifer Swamp Forest. 
As Zon points out, balsam swamp and balsam flat forests 
contain a certain small percentage of other conifers, especi- 
ally white cedar, tamarack and black spruce. Perhaps gen- 
erally each of these species tends to occur in pure stand 
(e. g. pure white cedar along Marion River) but over any 
considerable area, either a pretty general mixture or a mo- 
saic of pure stands of each may be presented. This is shown 
— especially as regards balsam, tamarack and white cedar —. 
in the stretch of built-up land from the inlet of Lake Bona- 
1 Zon, Raphael, Balsam Fir. Bull, U. S. Dept. Agri., No. 55:1914. 
