PINUS BANKSIANA, Lamb. 



PINUS DIVARICATA, Sudw. 

 Jack Pine. Banksian Pine. Scrub Pine. Grey Pine. 



Size. A small tree, rarely over 70 feet in height by 10 inches in 

 diameter. 



Growth. Rate very rapid in younger years, slow afterwards. 

 Sends out more than one set of whorls per year. Short lived; rarely 

 over 90 years. Studies in Minnesota showed for 74 dominant trees on 

 good soil growths of 8 inches in 31 years and 12 inches in 58 years; 91 

 dominant trees on poor soil, 8 inches in 45 years, and 12 inches in 82 years; 

 60 trees in an open stand, 8 inches in 30 years and 12 inches in 51 years. 



Root System. Very deep tap root with lateral roots spreading out 

 a short distance and then descending vertically. 



Bole. Medium taper. 



Crown. Open trees are very scrubby and limby. Small in a 

 dense stand. 



Tolerance. Less tolerant than red pine, white pine or any asso- 

 ciates. Its rapid growth allows it to compete successfully with other 

 species. 



Wood. Soft; not strong or durable; 30 pounds. 



Reproduction. Seed production prolific and annual. Sometimes 

 begins to bear seed at an age of 5 years. Flowers in May and June, and 

 cones mature in September. Some seeds are shed then but most cones 

 open only after fire. Bare soil is the best seed bed, leaves and grass being 

 a hindrance. 



Range. From Nova Scotia northwest through the Thousand 

 Islands to Hudson Bay to Great Bear Lake, and south, but not in the 

 Rockies. Southern limit Maine, New Hampshire, Vermont, New 

 York, Michigan to Manitoba. Best development in northern Sas- 

 katchewan. Tree of low altitudes. 



Soil. Coarse, dry, deep sands of flat plains are the natural home. 

 Xerophytic, the deep root system allowing it to withstand drought. 



Association. Typically in pure stands after fire ; also mixed with 

 red pine and scrubby oaks. On better soils found with white pine, aspen 

 and paper birch. 



General. Its use is chiefly local for ties, posts, etc. Canadian cut 

 1912, 28 million feet, or 0.9 of the total lumber cut; average mill price 

 $13.80. In cross ties it ranked first, supplying about 5.5 million or 40% 

 of the total at an average cost of 41 cents each. The U.S. Forest Service 

 recommended cutting in strips (sometimes in groups). Discourage on 

 better soils. 



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