Bcological Studies on a Sand Plain. 151 



ideal site for both the Red and the White Pine, the former often 

 occurring in pure stands. A splendid example of this type lies 

 near the lake at Frank's Bay and upon it the studies were carried 

 out. 



The method used consisted in nmning strips one chain in width 

 through the various associations and upon these the trees were 

 calipered down to 5 inches d. b. h. Square rod plots were taken 

 at the end of every chain to determine the reproduction and soil 

 flora. In the case of the cut-over areas the strips were narrowed 

 to one rod in width and the reproduction on the entire strip was 

 determined. 



This plain has an area of something over 1,000 acres and small 

 ridges outcrop through it in various places. The soil consists 

 principally of quartz and orthoclase, and varies in the texture 

 from very coarse sand around the low ridges to a fine sandy loam 

 in the deeper parts. This physical variation in texture is appar- 

 ently the cause of the reaction in the tree growth which produces 

 the several distinctly separated associations. 



These associations or societies are: i. Pure Red Pine; 2. Red 

 Pine-White Pine-Hardwoods ; 3. Pure Hemlock ; 4. Pure Hard- 

 wood- 



Pure Red Pine. 



The Red Pine (Pinus resinosa) occurs in a pure stand cover- 

 ing approximately 60 acres and is confined to the coarse and shal- 

 low sands near the ridges. This stand is past the period of its 

 maximum development and the rate of growth is now declining 

 with a consequent opening of the crown. The crown level is 

 even and stands at an average height of 90 feet. The average 

 stock density is 300 trees per acre, or expressed in basal areas 

 129 square feet. The composition is as below. 



The balance of 1 1 per cent, is made up of Poplar 2 per cent., Red 

 Maple 2 per cent.. Hard Maple 1.3 per cent-. White Birch 1.3 per 

 cent., Hemlock 1.5 per cent., Beech .5 per cent. Cedar .2 per cent, 

 and Red Oak .1 per cent. These last named species together 



