Diameter class. — The 2-inch diameter classes 

 extend from 1.0 inch below to 0.9 inch above the 

 stated midpoint. Thus, the 12-inch class includes 

 trees 11.0 inches to and including 12.9 inches d. b. h. 



Basal area. — Cross-sectional area, including bark, 

 of trees at breast height, measured in square feet. 



Growth 



Net annual growth of sawtimber. — The change 

 during a specified year in net board-foot volume of 

 live sawtimber on commercial forest land resulting 

 from natural causes. 



Net annual growth of growing stock. — The 

 change during a specified year in net cubic-foot 

 volume of growing stock on commercial forest land 

 resulting from natural causes. 



Annual Cut 



Annual cut of sawtimber. — The net board-foot 

 volume of live sawtimber trees cut or killed by logging 

 on commercial forest land during a specified year. 



Annual cut of growing stock. — The net cubic- 

 foot volume of live sawtimber and poletimber trees 

 cut or killed by logging on commercial forest land 

 during a specified year. 



Softwood Tree Grades 



Grade 1 (smooth 8 trees) . — Not less than 20 feet 

 of clear bole and at least 40 percent of the merchant- 

 able length clear of limbs and knots in sections not 

 less than 8 feet in length. All cedar sawtimber trees 

 were graded as No. 1 . 



Grade 2 (limby trees). — Not less than 12 feet of 

 clear bole and 25 to 39 percent of the merchantable 

 length clear of limbs and knots in sections not less 

 than 8 feet in length. 



Grade 3 (rough trees). — Merchantable trees 

 below grade 2 specifications. 



Hardwood Log Grades for Standard Lumber Logs 9 



Grade 1 . — Logs having five-sixths or more of their 

 length on the 3 best faces in clear-cuttings not less 



than 5 feet long; they yield, on the average, at least 

 65 percent of their volume in No. 1 Common and 

 better grades of lumber. 



Grade 2. — Logs having two-thirds to five-sixths of 

 their entire length on the 3 best faces in clear-cuttings 

 not less than 3 feet long; they yield, on the average, at 

 least 40 percent of their volume in No. 1 Common and 

 better grades of lumber. 



Grade 3. — Logs below grade 2, having one-half or 

 more of their entire length on the 3 best faces in clear- 

 cuttings not less than 2 feet long; they yield, on the 

 average, at least 1 3 percent of their volume in No. 1 

 Common and better grades of lumber. 



Hardwood Tie and Timber Log Specifications 



Logs which do not meet the clear-cutting require- 

 ments of standard lumber logs, but which are sound, 

 reasonably straight, and without large knots or knot 

 clusters; they are suitable for ties and low-grade 

 structural timbers. 



Stand Quality 



Fair and better. — A stand in which at least four 

 grade 2 or better hardwood logs or softwood trees are 

 present per acre. 



Poor. — A stand in which fewer than four grade 2 or 

 better hardwood logs or softwood trees are present per 

 acre. 



Supplemental Tables 



The tables that follow present additional statistical 

 data, and include the standard Forest Survey tables 

 which make it possible to compare or compile forest 

 statistics for a group of States. 



Table 8. — Land area, by major classes of land, Tennessee, 1948—50 



8 Except as noted in the case of cedar. 



9 For detailed external specifications of log grades used, see 

 Forest Service Committee on Interim Hardwood Sawlog Grades, 



'Interim sawlog grades for southern hardwoods," Southern 

 Forest Experiment Station, 9 pp., illus. Rev. 1948. 



Class of land 



Area 



Forest: 



Thousand acres 

 12,353.8 



Noncommercial: 



253.8 











Total ._ 



12, 607. 6 





14, 247. 4 









26, 855. 







1 Includes some acreage of water according to Survey standards of area classifi- 

 cation but defined by the Bureau of Census as land. 



Tennessee's Timber Economy 



43 



