**Expected
Volume and Value of Structural Dimension Lumber from**

**25-, 30-, 35-,
40-, and 50-Year Old Loblolly Pine ****Plantation**** Timber**

Dr. Evangelos J. Biblis,
Professor Emeritus & Dr. Honorio F. Carino, Professor

School of Forestry &
Wildlife Sciences

Tel. - (334) 844-1090, Fax
- (334) 844-4221

E-Mail – biblisej@auburn.edu, or carinhf@auburn.edu

The expected volume and value (based
on Summer 2000 prices) of structural dimension lumber derived from
plantation-grown timber of 25-, 30-, 35-, 40-, and 50-year old loblolly pine (Pinus
taeda L.) were estimated and used to determine stumpage values through
regression analysis. Also, incremental analysis in conjunction with
discounted-cash-flow techniques were used to determine the economic
desirability of deferring the harvesting of a loblolly pine plantation stand of
a given age for purposes of producing structural dimension lumber.

V_{k} =
_{}P_{ij} R_{ij} [1]_{}

R_{ij} = unit price ($/mbf or $/cu.m) of tested
dimension lumber of a given size i and grade j.

Y1 = -7.86 +
0.96X, r^{2} = 0.82 [2]

Y2
= 5.00 + 8.00X, r^{2}
= 0.94 [3]

R =
[(F/P)^{1/n} - 1] x 100 [4]

where: R = expected incremental rate of return
(%)

F = expected future value ($) of stress-graded
dimension lumber produced

per acre of
loblolly pine plantation after n years from a base age.

9. Southern Pine Inspection Bureau. 1994. Grading rules. SPIB, Pensacola, FL.

^{1Stress grades
are based on SPIB allowable design values of "Fb" and "E" as
listed in Tables 1a, 1b, and 1c, pages A3, A4, and A5 of Standard Grading Rules
for Southern Pine Lumber, 1994 (9).}

^{1The expected
values of unit value and total volume were calculated using Equations 2 and 3,
respectively, and the expected value yield per acre is the product of the two.}

^{}

^{ 1In this case, stumpage is based on the value of stress-graded
dimension lumber product yield. Stress grades are based on SPIB
allowable design values of "Fb"
and "E" as listed in Tables 1a, 1b, and 1c, pages A3, A4, and A5 of
Standard Grading Rules for Southern Pine Lumber, 1994 (9).}