THE NORTHERN HARDWOOD FOREST. 



17 



generalization can not be applied to all species. White elm, for 

 example, may have a wider crown than beech, which is much more 

 tolerant. 



Table 5.— Comparative croivn widths of northern hardwoods based on diameter breast high. 



Diameter 

 breast high. 



Average width of crown. 



Diameter, 

 breast high. 



Average width of crown. 



Beech. 



Sugar 

 maple. 



Yellow 

 birch. 



Bass- 

 wood. 



Beech. 



Sugar 

 maple. 



Yellow 

 birch. 



Bass- 

 wood. 



Inches. 

 1 



Feet. 



3 



5 



8 



10 



13 



15 



18 



20 



22 



24 



26 



28 



29 



30 



Feet. 



3 



5 



8 



10 



Feet. 

 3 



5 

 7 

 9 



Feet. 



3 



5 



8 



10 



12 



14 



15 



16 



17 



18 



18 



19 



19 



19 



Inches. 

 15 



Feet. 

 31 

 32 

 33 

 34 

 34 

 35 

 36 

 36 

 37 

 37 

 38 

 39 



Feet. 

 27 

 28 

 29 

 30 

 31 

 32 

 34 

 35 

 36 

 37 

 38 

 39 



Feet. 

 23 

 25 

 26 

 27 

 28 

 29 

 30 

 31 

 33 

 34 

 35 

 36 



Feet. 

 20 



2 



16 . 



20 



3 



17... 



20 



4 



18 .. 



21 



5 



13 11 



19 



21 



6 



14 

 16 

 18 

 19 

 21 

 22 

 23 

 25 

 26 



12 

 14 

 15 

 16 

 18 

 19 

 20 

 21 

 22 



20... 



22 





21 



22 



8 



22 



23 



9 



23 



24 



10 



24 . 



24 



11 



25 



25 



12 



26 



26 



13 



Basis, trees 





14 



82 



67 



42 



195 







Table 6. —Comparative croivn lengths of northern hardwoods based on total height of tree. 





tal height of 

 tree. 



Average length of crown. 



Total height of 

 tree. 



Average length of crown. 



To 



Beech. 



Sugar 

 maple. 



Yellow 

 birch. 



Bass- 

 wood. 



Beech. 



Sugar 

 maple. 



Yellow 

 birch. 



Bass- 

 wood. 



5... 



Feet. 



Feet. 



3 



6 



8 



11 



14 



17 



20 



23 



26 



29 



32 



35 



39 



Feet. 



2 



5 



7 



9 



12 



14 



16 



19 



21 



24 



26 



28 



31 



Feet. 



2 



4 



6 



8 



10 



12 



14 



17 



19 



21 



24 



26 



29 



Feet. 



3 



5 



7 



10 



12 



14 



16 



18 



19 



21 



23 



24 



25 



Feet. 

 70 



■ Feet. 

 42 

 45 

 48 

 51 

 54 

 56 

 59 

 62 

 65 



Feet. 

 33 

 36 

 38 

 40 

 43 

 45 

 47 

 50 

 52 

 54 

 57 



Feet. 

 31 

 34 

 37 

 40 

 43 



Feet. 

 27 



10 



75 



28 



15 



80 



29 



20 



85 



31 



25 



90 



32 



30 



95 



33 



35 



100 



34 



40 



105 



35 



45 



110 



36 



50 



115 



37 



55 



120 





39 



60 



Basis, trees 







65 



87 



72 



47 



253 







GROWTH. 



The rate of growth of a given species depends on the soil, the 

 climate, and especially sunlight. Theoretically the growth per acre 

 is the same whether there are few or many trees, provided the supply 

 of light is completely utilized by a continuous crown cover. The 

 northern hardwood forest in its virgin condition was characterized by 

 extreme crown density, caused not only by the large number of trees 

 which the fertile soil produced, but also by the difference in shade 

 endurance. Under the light-needing crowns of the tall pines, elms, 

 or basswoods, the tolerant birch, beech, and maple grew without 

 much difficulty, providing an efficient, wood-producing "lower story" 

 of foliage. The total amount of wood produced was very large. 

 637° -Bull. 285—15 -2 



