LAWS OF TALL-TREE GROWTH 547 



These trees are more rcmarkaljle for size than for height. They are 

 roughly about one-eight to one-sixth their greatest possible height in 

 still air. 



Louisiana Cypress 



Trees less than 125 feet high are relatively slightly taller than white 

 pines. Those higher than this are relatively lower than white pines. 



Maryland Cypress 



The Maryland cypresses are when young and less than 115 feet 

 high relatively taller, as comi^ared with the greatest height they can 

 attain in still air, than Douglas firs, and are relatively the tallest trees 

 I have found. The tree 61 feet high on a 6-inch diameter is 0.52 of 

 the greatest height possible, and is as tall a tree, relatively, as the 

 Douglas fir 318 feet high, diameter 67.2 inches. 



The fact that the diameters all progress in arithmetic series, with a 

 difference of one inch, gives these trees a somewhat "academic" appear- 

 ance.^ 



Tennessee White Oak 



It will be observed, on comparing them with Michigan and Penn- 

 sylvania pines, that white oaks are as tall, on a given stump radius, as 

 compared with the greatest height they can reach on that radius, as are 

 pines. However, it takes the white oak 200 years to acquire a stump 

 diameter of 21 inches which the pines referred to reach in about 90 

 years. White oaks cannot stand as high on a given stump as can white 

 pines. It is interesting to observe that the height of white oaks on a 

 selected stump radius, as compared wdth the height of Michigan and 

 Pennsylvania pines on the same radius, are about as 53. 1 to 59.4, the 

 numbers in the last column of the first table (E) as comparing the greatest 

 heights attainable on any stump radius. 



The Tallest White Oak 



The tallest w^hite oak stood 150 feet high. On what diameter I do 

 not know. The tallest found in Forest Service lumbering operations 

 was 126 feet high with a stump-radius of 15 inches. 



For this tree h = 20.6 Vr- which is relatively the same as at 120 

 years in the table. 



2 Ed. Note. — This is because a table showing height based on diameter has 

 been used in this case. In most of the other cases. Professor Bohannan has used 

 growth or yield tables which show diameter on age, height on age, and hence in- 

 directly height on diameter. 



