40 BULLETIN 212, U. S. DEPARTMENT OF AGRICULTURE. 



Table 6. — Height growth of cypress saplings under full light in southern Louisiana. 



Age. 



Height. 



Age. 



Height. 



Age. 



Height. 



Years. 



1 



2 



3 



4 



Feet. 

 0.8 

 1.7 

 3.0 

 4.3 



Years. 

 5 



Feet. 

 5.5 

 7.0 

 9.0 



Years. 

 8 



Years. 

 11.4 

 14.8 

 18.8 



6 



9 



7 



10 





1 Based upon age counts of 110 trees from 3 to 32 years old. This and the following tables of growth and 

 volume in Louisiana are based on measurements by F. T. McLean, Forest Examiner, Forest Srevice. 



Second-growth or open-grown cypress in Louisiana averages 16 

 or 18 feet in height at 10 years, 31 feet at 20 years, and continues at 

 a gradually diminishing rate until it reaches a full height of about 100 

 feet in the first 100 years. The height continues to increase during 

 the next one to three centuries; then the fungus causing pecky 

 cypress disintegrates the heartwood in the top and winds start the 

 downward or backward stage in the height of the tree. The average 

 heights of stands 350 to 500 years old are perhaps about the same as 

 young virgin stands at 60 to 80 years; the prime stage in respect to 

 height is approximately from 150 to 300 years. Individuals which 

 live to be 600 years old probably spend about one-half of their time 

 in the decadent stage. 1 



Table 7 shows the height at various ages up to 100 years of second- 

 growth cypress in Maryland and Louisiana supplied with abundant 

 overhead light, as, for example, in logged areas. While the height 

 growth of virgin stands may be interesting, knowledge of the rate of 

 growth of younger stands is more valuable in figuring the profitable- 

 ness of managing young cypress forests. The three columns of 

 growth in Table 7 represent three grades of f avorableness of situation. 

 In comparison, the slow height growth shown in Table 8 of trees 

 grown under the heavy shade of virgin forests is very striking. 



Table 7. — Height of second-growth cypress on the basis of age. 



Age. 



Height. 



Maryland. 2 



Louisiana. s 



Maximum. 



Average. 



Minimum. 



Maximum . 



Average. 



Minimum. 



Years. 



10 



20 



30 



40 



50 



60 



70 



80 



90 

 100 



Feet. 

 26 

 44 

 58 

 71 

 82 

 91 

 99 

 106 

 113 

 119 



Feet. 

 11 

 22 

 33 

 46 

 60 

 72 

 81 

 88 

 95 

 101 



Feet. 

 3 

 7 



12 

 18 

 25 

 32 

 39 

 44 

 50 

 54 



Feet. 

 24 

 45 

 61 

 75 

 86 

 97 



Feet. 

 17 

 31 

 43 

 54 

 65 

 74 

 83 

 92 

 101 

 109 



Feet. 

 9 

 17 

 26 

 34 

 43 

 51 

 60 

 69 

 78 

 86 











1 Acknowledgment is made to Mr. George E. Watson, secretary of the Southern Cypress Manufacturers' 

 Association, and various operating members of the association, for assistance rendered the writer in the 

 collection of field data used in the bulletin. 



2 Based on sectional age counts of 68 trees, also total heights of 221 additional trees 6 to 103 years old. 



3 Based on sectional age counts of 42 trees 38 to 89 years old. 



