"L,
Y&,arch 1987
Bulletin 869 (technical)
--
Weight and Volume
Prediction Equations for
Sand Pine Trees in Florida
D. L. Rockwood, K. V. Reddy, C. W. Comer,
W. H. McNab, and K. W. Outcalt
Agricultural Experiment Station
Institute of Food and Agricultural Sciences
University of Florida, Gainesville
J. M. Davidson, Dean for Research
- -- --- -"
Abstract
Sixty direct-seeded Ocala and 40 planted Choctawhatchee sand pine
trees in Florida were sampled to generate equations predicting 20
components: stem volumes inside- and outside-bark, stem wood and
bark green and dry weights, branch wood and bark green and dry
weights, and tree green and dry weights. Differences between the two
varieties were speculated for certain components. These equations
apply to trees as large as 9 inches in DBH and 55 feet in height.
Key words: Pinus clausa var. immuginata, Pinus clausa var. clausa,
green weight, dry weight, tree components.
Acknowledgments
Support for the research reported here was provided by the Utiliza-
tion of Southern Timber Research Work Unit SE-3101, Southeastern
Forest Experiment Station, USDA Forest Service, under cooperative
agreement A8fs-9,961, suppl. 51. Sample trees were taken from sites
provided by the Lake George District, Ocala National Forest, USDA
Forest Service; St. Joseph Land and Development Company; Forest
and Lakes Plantations, Inc.; Prosper Energy Corporation; and
Champion International.
WEIGHT AND VOLUME PREDICTION EQUATIONS
FOR SAND PINE TREES IN FLORIDA
D. L. Rockwood, K. V. Reddy, C. W. Comer,
W. H. McNab, and K. W. Outcalt
D. L. Rockwood is Associate Professor, K. V. Reddy is Assistant in
Biomass, and C. W. Comer is Assistant Research Scientist, respectively,
Department of Forestry, University of Florida, Gainesville, 32611;
W. H. McNab is Research Forester and K. W. Outcalt is Soil Scientist,
Southeastern Forest Experiment Station, USDA Forest Service,
Asheville, NC 28804, and Olustee, FL 32072, respectively.
Introduction
Nearly all of the tree weight and volume prediction equations
available for sand pine (Table 1) apply to Choctawhatchee sand pine
(CSP) (Pinus clausa var. immuginata Ward). Merchantable volumes
of trees in natural stands are well estimated by the equations of Taras
(1980) and the Southeastern Forest Experiment Station. Green and dry
weights of tree components, however, are estimable based on sampling
in only one natural stand (Taras 1980). Green weights of trees planted
at conventional spacings in one location are predicted by Buckeye
Cellulose's equations, which are particular to each of the four ages
sampled, while the volume and weight equations of McNab et al. (1985)
developed at one location are applicable to a range of spacings. Other
equations for planted stands (Rockwood et al. 1980, Frampton 1981)
apply to closely spaced trees in two locations. Lacking for CSP are equa-
tions for premerchantable trees in natural stands and equations for
plantation trees based on wide geographic and age sampling. For Ocala
sand pine (OSP) (P. clausa var. clausa Ward), natural and planted tree
equations are needed. Due to the unavailability of suitable equations,
numerous research studies (e.g., Burns 1973, Burns and Brendemuehl
1978, Rockwood and Goddard 1980, McNab and Carter 1981, Hebb
1981) utilized only general approximations of tree volume.
To provide stand level productivity assessments, an intensive sam-
pling of sand pine stands was initiated in 1982. From this effort, data
for tree weight and volume prediction equations for OSP and CSP were
derived.
Table 1. Summary of existing tree weight and volume prediction equations and associated methodology for Choctawhatchee (CSP) and Ocala (OSP) sand pines.
No. of Tree Size Tree Locality
Source Trees DBH Height Age in Florida Type of Stand Predicted Content(s)
(in) (ft) (yrs)
Taras 1980 36 3.9-14.7 24-67 37-88 Northwest Uneven-aged, natural 16 volumes and 38 green and dry
Rockwood et al. 1980
Frampton 1981
SEFES"
Buckeye Celluloseb
McNab et al. 1985
0.8-2.8
0.9-3.6
1.4-4.7
9.2-17.8
11.5-28.7
20.7-44.8
6.5 Clarksville
12.5 Clarksville
17.5 Clarksville
312 0.3-4.7 4.6-19.5 4-6 Archer
340 1.0-18.9 18-92
CSP, SI = 50
CSP planted at 4'x 3'
CSP planted at 4'x 3'
CSP planted at 3'x 2.5'
CSP planted at 15'x 2'
Statewide Natural/Planted
CSP and OSP
2-5 8 Perry
2-6 10 Perry
2-8 12 Perry
2 18 Perry
2.3-11.1 21.0-59.0 12-27 Clarksville
0.7-3.7 11.0-21.2 7 Clarksville
CSP planted at 9'x6'
CSP planted at 9'x6'
CSP planted at 9'x6'
CSP planted at 6'x6'
225-800 planted CSP/acre
830-955 planted CSP/acre
weights for wood, bark, and wood
plus bark of various stem, branch,
and needle components.
Stem volume, green weight, and
dry weight for each age group
Stem, branch, and total green weight.
Stem merchantable and total volume
for saplings, poletimber, and
sawtimber; board content.
Merchantable stem and total green
weight for each age group.
Stem volumes and green and dry
weights of stem, branch, and nee-
dle components for each age group.
SJ. P. McClure, Forest Inventory and Analysis, Southeastern Forest Experiment Station, USDA Forest Service, Asheville, North Carolina, personal com-
munication. Sample trees are composites of Choctawhatchee and Ocala varieties in planted and natural stands as encountered in conduct of forest surveys
in Florida.
SI. W. Lininger, Buckeye Cellulose Corporation, Perry, Florida, personal communication.
Materials and Methods
Field
Ninety-nine permanent inventory plots were installed in planted or
direct-seeded OSP stands and CSP plantations randomly selected to
represent a range of stand densities and ages from 5 to 25 years. Most
of the 59 OSP plots were located in Marion County in central Florida.
The 40 CSP plots were primarily situated in northwest Florida.
Tree sampling locations were randomly chosen to represent sand pine
occurring on the 99 permanent plots. The 12 OSP plots in direct-seeded
stands in Marion County ranged in age from 6 to 21 years and in den-
sity from 503 to 8,903 trees per acre (Table 2). The eight CSP plots
in plantations in four counties in west Florida were from 5 to 20 years
in age and from 360 to 890 trees per acre in density. At each of these
20 locations, five sample trees in the vicinity of the permanent plot
were randomly chosen according to stratification of the diameter breast
height (DBH) range among the trees on the plot.
Sixty OSP trees were felled in November 1982 and 40 CSP trees
in October 1983 (Table 3). After felling at groundline, tree DBH, total
height, and height to live crown were recorded (Figure 1). Disks
approximately 1 inch thick were removed at 4.9- foot intervals begin-
ning at the base of the felled tree. Branches were removed and
weighed by lower-, mid-, and upper-crown components. A represen-
tative branch was selected from each crown section. Disks and branch
samples were then weighed and bagged.
Table 2. Location in Florida, age, and stand density of 12 Ocala (OSP)
and eight Choctawhatchee (CSP) sand pine plots contributing
sample trees.
Location Age Trees/Acre Location Age Trees/Acre
(county) (years) (county) (years)
---------------------------------------. ----OS----- --- -------.--- ---------
Marion 12 733 Marion 10 1,619
Marion 10 1,255 Marion 13 791
Marion 6 8,903 Marion 14 2,914
Marion 7 1,619 Marion 20 612
Marion 9 850 Marion 21 503
Marion 15 539 Marion 17 737
-------------.. ------------------- --....... .CSP------------- -------------------
Liberty 20 396 Washington 20 360
Liberty 16 558 Calhoun 11 414
Washington 5 890 Walton 11 809
Washington 12 629 Walton 20 809
Laboratory
Stem disks and sample branches were measured for wood and bark
green weight-dry weight ratios and specific gravity, and foliage green
weight-dry weight ratios were determined. Diameters outside- and
inside-bark were determined for each stem disk, after which wood
and bark green weights were obtained. Disk volumes were determined
by the water displacement method. After drying at 1030 C., disk dry
weights were obtained, and weight ratios and specific gravities
calculated. Each sample branch was partitioned into foliage and wood
plus bark components which were weighed green. A subsample of the
branch was separated into wood and bark components. Then all com-
Table 3. Distribution by DBH and height of 60 Ocala (OSP) and 40
Choctawhatchee (CSP) sand pine sample trees.
Total Height (ft.)
DBH (in.) 5 10 15 20 25 30 35 40 45 50 55 Total
...........-------------------- o---- -------------------- --OS--
1 5 10 4 2 21
2 1 4 5 1 2 13
3 3 2 2 1 1 9
4 2 1 2 1 6
5 1 1 2 2 6
6 1 1
7 1 1 2
8 1 1
9 1 1
Total 5 11 8 10 6 5 4 4 3 2 2 60
Mean DBH = 2.8 in., DBH Range = 0.4-8.6 in.,
Mean Height = 24.0 ft., Height Range = 6.9-54.8 ft.
... ---------------------- P--------------CSP -----. .---
1 1 3 4
2 4 1 5
3 2 2 1 1 6
4 1 3 2 1 7
5 2 1 2 5
6 3 1 1 1 6
7 1 1 1 3
8 1 1 2
9 2 1 2
Total 2 3 6 2 2 5 8 5 1 5 2 40
Mean DBH = 4.5 in., DBH Range = 0.7-8.7 in.,
Mean Height = 31.2 ft., Height Range = 6.9-55.1 ft.
BRANCH AT 5/6
CROWN LENGTH
BRANCH AT 1/2
CROWN LENGTH
BRANCH AT 1/6
CROWN LENGTH
HEIGHT
TO
CROWN
BASE
TOTAL
HEIGHT
Figure 1. Sampling procedures used for sand pine tree volume and
weight determination.
ponents were dried and dry weights taken. OSP and CSP samples
were processed by the USDA Forest Service, Athens, Georgia, and
the University of Florida, respectively.
Analysis
Field and laboratory data were combined to generate 20 com-
ponents: stem volumes inside- and outside-bark, stem wood and bark
green and dry weights, branch wood and bark green and dry weights,
foliage green and dry weights, crown green and dry weights, and tree
green and dry weights. Stem volumes inside- and outside-bark were
derived using disk diameters in Smalian's formula for all sections
except the top section, which was estimated by the conical formula.
Stem green and dry weights were derived from stem volumes by use
of green weight-volume ratios and specific gravities weighted by the
cross-sectional areas of the stem disks. Sample branch foliage, wood,
and bark proportions and associated green weight-dry weight ratios
were applied to tree crown green weights to estimate branch wood,
branch bark, and foliage components. Summations of component parts
were performed to obtain stem, branch, foliage, crown, and tree
weights.
Using DBH and total height (TH) as independent variables, the com-
bined variable
Y = bo + b,*DBH2*TH
and allometric
Y = b,*DBHb2*THb3
as linearized by base e logarithmic transformations
In Y = (In b,) + b,(ln DBH) + b,(ln TH)
models were examined. The bias for the transformed allometric model
was determined as described by Baskerville (1972). For each compo-
nent, each model was evaluated by the coefficient of determination,
standard error of the estimate, and pattern of residuals. Prediction
equations of the same form were compared across varieties using the
GLM procedure in the Statistical Analysis System. By employing a
dummy variable for varieties, equations parameters were compared
by means of t-tests. Whole equations were tested by F-tests involv-
ing mean squares derived from Type I sums of squares (R. C. Littell,
personal communication).
Results and Discussion
Sample Trees
The OSP sample trees were skewed toward the smaller sizes
(Table 3). Of the 60 trees, 37 were less than 4 inches in DBH and
30 feet.in height as a consequence of the emphasis on selecting plots
in younger stands. The 10 trees greater than 4 inches in DBH and
30 feet in height included trees up to 21 years old. Stands with less
than 1,210 trees per acre contributed 35 trees; stands with more than
1,210 trees per acre provided 25 trees. Within each of these density
classifications, sample trees were similarly distributed across DBH
and height classes.
The CSP sample trees were obtained from plantations with typical
commercial pulpwood densities and were up to 20 years old (Table 2).
CSP trees were somewhat larger than the OSP trees (Table 3) and
were well distributed across DBH and height classes.
Predictive Equations
In general, the combined variable model (Tables 4 and 5) was
superior for stem and whole tree components, and the allometric
model (Table 6) was better for branch, foliage, and crown charac-
teristics. These non-stem components were inversely related to tree
height, indicating that crown components did not increase in quan-
tity with increasing tree height, a fact observed in other studies
(Rockwood et al. 1980, Frampton 1981).
Equations estimating stem and whole tree contents of OSP and CSP
had high coefficients of determination (Tables 4 and 5). Coefficients
of 0.97 were typical for stem equations. Whole tree equations were
less reliable, with coefficients as low as 0.91. Crown components were
predicted with lowest precision, with OSP branch, foliage, and crown
estimation usually better than for CSP (Tables 4, 5, and 6).
The combined variable equations presented in Tables 4 and 5 have
the desirable property of additivity, i.e., summed regression coeffi-
cients of components equal the coefficients of the derived total. For
example, the OSP stem dry weight coefficients for wood and bark sum
to those for the stem (within rounding limits):
b, b,
Wood 1.2099 .031162
Bark .7232 .004396
Wood + Bark 1.9330 .035556
and similarly on a whole tree basis:
bo b,
Stem Wood + Bark 1.9330 .035556
Branch 2.2633 .013860
Foliage 2.1671 .003733
Tree 6.3634 .053146
Estimates obtained from these equations consequently are additive,
making estimates of tree components add to the various estimated
totals.
Table 4. Combined variable Ocala sand pine tree weight and volume
prediction equations for 20 components.
Equation Parameters"
Component Y b0 b, R2
Stem Wood
Vol. I.B.
Green Wt.
Dry Wt.
Stem Bark
Green Wt.
Dry Wt.
Stem
Vol. O.B.
Green Wt.
Dry Wt.
Branch Wood
Green Wt.
Dry Wt.
Branch Bark
Green Wt.
Dry Wt.
Branch
Green Wt.
Dry Wt.
Foliage
Green Wt.
Dry Wt.
Crown
Green Wt.
Dry Wt.
0.0333 .001182
2.8995 .067179
1.2099 .031162
lb. 1.3849 .007908
lb. 0.7232 .004396
0.0612 .001342
4.2842 .075087
1.9330 .035556
3.8382 .025426
1.5582 .011558
1.5454 .006863
0.7050 .002298
5.3837 .032289
2.2633 .013860
5.5314 .009746
2.1671 .003733
lb. 10.9149 .042035
lb. 4.4304 .017593
.990
.987
.976
.947
.941
.991
.987
.978
.758
.767
.739
.581
.760
.754
.494
.481
.708
.711
Tree
Green Wt. lb. 15.1993 .117122 .938
Dry Wt. lb. 6.3634 .053146 .945
" Equation format: Y = b, + b,*DBH2*TH with DBH in inches and TH in
feet.
The allometric equations for crown components (Table 6) are not
additive but may be used when more precise estimates of these com-
ponents are needed. Use of these equations with the stem and tree
Table 5. Combined variable Choctawhatchee sand pine tree weight
and volume prediction equations for 20 components.
Equation Parameters"
Component Y b. b, R2
Stem Wood
Vol. I.B.
Green Wt.
Dry Wt.
Stem Bark
Green Wt.
Dry Wt.
Stem
Vol. O.B.
Green Wt.
Dry Wt.
Branch Wood
Green Wt.
Dry Wt.
Branch Bark
Green Wt.
Dry Wt.
Branch
Green Wt.
Dry Wt.
Foliage
Green Wt.
Dry Wt.
Crown
Green Wt.
Dry Wt.
0.1078
5.1041
2.0699
.000984
.063811
.031123
.966
.983
.984
3.0532 .007886 .924
1.5446 .003962 .906
0.1665
8.1573
3.6145
.001149
.071697
.035085
.975
.985
.988
lb. 10.2182 .023744 .685
lb. 4.2774 .010712 .670
lb. 2.6982 .004487 .656
lb. 0.8552 .002228 .686
lb. 12.9164 .028231 .684
lb. 5.1326 .012941 .686
lb. 9.6580 .015698 .564
lb. 3.6189 .006230 .577
lb. 22.5744 .043929 .645
lb. 8.7515 .019166 .665
Tree
Green Wt. lb. 30.7318 .115626 .908
Dry Wt. lb. 12.3659 .054252 .938
Equation format: Y = bo + b,*DBH2*TH with DBH in inches and TH in
feet.
Table 6. Allometric Ocala (OSP) and Choctawhatchee (CSP) sand pine
tree weight prediction equations for 10 crown components.
Equation Parametersa
Component Y b, b2 b, R2
------------. --. -------------------- OSP-------------------------
Branch Wood
Green Wt.
Dry Wt.
Branch Bark
Green Wt.
Dry Wt.
Branch
Green Wt.
Dry Wt.
Foliage
Green Wt.
Dry Wt.
Crown
Green Wt.
Dry Wt.
lb. 202.88 3.6022 -2.0791 .872
lb. 46.40 3.3528 -1.7905 .865
lb. 17.49 2.8563 -1.4069 .872
lb. 6.98 2.4272 -1.2576 .775
lb. 176.15 3.3579 -1.8661 .880
lb. 41.90 3.0444 -1.5750 .868
lb. 1134.10 3.3014 -2.5721 .820
lb. 593.90 3.3292 -2.6709 .798
lb. 828.99 3.3270 -2.1840 .870
lb. 250.06 3.1448 -2.0211 .855
---- --------------................. CSP ----------------- --------
Branch Wood
Green Wt.
Dry Wt.
Branch Bark
Green Wt.
Dry Wt.
Branch
Green Wt.
Dry Wt.
Foliage
Green Wt.
Dry Wt.
Crown
Green Wt.
Dry Wt.
lb. 246.26 3.2899
lb. 107.18 3.3270
53.17 2.7407
16.79 2.6751
301.94 3.1762
123.46 3.1982
lb. 195.14 3.1225
lb. 61.25 3.0645
lb. 496.44 3.1593
lb. 184.48 3.1576
-2.0428 .718
-2.0593 .723
-1.7957 .671
-1.6877 .688
-1.9940 .711
-1.9887 .722
-1.9802 .698
-1.8928 .697
-1.9900 .708
-1.9574 .717
" Equation format: Y = b,*DBHb2*THb3with DBH in inches and TH in
feet.
Table 7. Comparison of Ocala and Choctawhatchee sand pine individ-
ual tree prediction parameters and equations and predicted
values through application of equations to a 4-inch DBH,
30-foot tree.
Significance of Predicted Value for
Component Parameters Ocala Choctawhatchee
bo b, b2 b3 Equation
Stem
Wood
Vol. I. B. (ft.3)
Green Wt. (lbs.)
Dry Wt. (lbs.)
Bark
Green Wt. (Ibs)
Dry Wt. (lbs.)
Total
Vol. O. B. (ft.3)
Green Wt. (lbs.)
Dry Wt. (lbs)
Crown
Branch
Wood
Green Wt. (lbs.)
Dry Wt. (lbs.)
Bark
Green Wt. (lbs.)
Dry Wt. (lbs.)
Total
Green Wt. (lbs.)
Dry Wt. (lbs.)
Foliage
Green Wt. (lbs.)
Dry Wt. (lbs.)
Total
Green Wt. (lbs.)
Dry Wt. (lbs.)
Total
Green Wt. (lbs.) **
Dry Wt. (lbs.) **
**
**
**
** **
** NS
0.600
35.1
16.2
** 5.2
** 2.8
** NS NS NS
** NS NS NS
0.705
40.3
19.0
25.4
11.0
** NS NS NS 7.7
** NS NS NS 2.8
** NS NS NS 32.4
** NS NS NS 13.4
** NS NS NS 17.5
** NS NS NS 6.8
** NS NS NS 49.6
** NS NS NS 20.2
NS NS 71.4
NS NS 31.9
NS and ** Non-significant at the 5% and significant at the 1% levels, respectively.
0.580
35.7
17.0
6.8
3.4
0.718
42.6
20.5
22.6
9.8
equations in Tables 4 and 5, however, would result in inconsisten-
cies among the estimates, as shown by the failure of the stem and
crown components in Table 7 to sum to the totals. Corrections for the
biases due to the log transformations in the allometric equations,
underestimates which ranged from 18 to 26%, were incorporated in-
to the b, coefficients in Table 6.
At least one equation parameter differed between OSP and CSP
for every component, and prediction equations were significantly dif-
ferent for the eight stem components (Table 7). The lack of signifi-
cant differences between equations for crown and whole tree traits
is attributable to the poorer fit of these equations.
Predicted differences in OSP and CSP tree contents derived by
applying the combined variable stem and tree and allometric crown
equations to a tree with a 4-inch DBH and 30-foot height (Table 7),
while statistically significant, are speculative. Factors such as stand
regeneration method (direct-seeded vs. planted), sampling locality
(Marion County vs. northwestern Florida), stand density, mean tree
size, and tree size distribution are confounded with the OSP and CSP
samples and make precise comparisons of the two varieties impossible.
Application
The equations in Tables 4, 5, and 6 may be applied when tree DBH
and total height are known. To illustrate for the 4-inch, 30-foot OSP
tree values shown in Table 7,
Stem wood dry weight = 1.2099 + .031162*42*30 = 16.2 lbs.
Stem bark dry weight = .7232 + .004396*42*30 = 2.8 lbs.
Stem dry weight = 1.9330 + .035556*42*30 = 19.0 lbs.
The allometric equations in Table 6 require exponentiation of tree
DBH and total height. Again for the 4-inch, 30-foot OSP tree in
Table 7,
Crown dry weight = 250.06*43-1448"302.0211 = 20.2 lbs.
Conclusions
Numerous biomass components of OSP and CSP trees can be
estimated by the equations presented. These equations expand
previously available equations in terms of tree sizes, geographic ap-
plicability, and tree components. Constraint should, however, be
used in applying the reported equations to trees greater than 9 inches
in DBH or 55 feet in height and growing under conditions different
than those represented by the sampling.
Literature Cited
Baskerville, G. L. 1972. Use of logarithmic regression in the estimation of
plant biomass. Can. J. For. Res. 2(1):49-53.
Burns, R. M. 1973. Comparative growth of planted pines in the sand hills
of Florida, Georgia, and South Carolina. USDA For. Serv. Gen. Tech. Rpt.
SE-2:124-133.
Burns, R. M., and R. H. Brendemuehl. 1978. Sand pine: early responses to
row thinning. USDA For. Serv. Res. Note SE-262. 8p.
Frampton, L. J., Jr. 1981. Genetic variation of traits important for energy
utilization in sand and slash pines. M.S. thesis, Univ. of Fla. 135 p.
Hebb, E. A. 1981. Choctawhatchee sand pine growth on a chemically prepared
site 10-year results. S. J. Appl. For. 5(4):208-211.
McNab, W. H., and A. R. Carter. 1981. Sand pine performance on South
Carolina sandhills. S. J. Appl. For. 5(2):84-88.
McNab, W. H., K. W. Outcalt, and R. H. Brendemuehl. 1985. Weight and
volume of plantation-grown Choctawhatchee sand pine. USDA For. Serv.
Res. Paper SE-252. 44 p.
Outcalt, K. W. 1983. A comparison of sand pine varieties in central Florida.
S. J. Appl. For. 7(1):58-59.
Rockwood, D. L., L. F. Conde, and R. H. Brendemuehl. 1980. Biomass pro-
duction of closely spaced Choctawhatchee sand pine. USDA For. Serv. Res.
Note SE-293. 5 p.
Rockwood, D. L., and R. E. Goddard. 1980. Genetic variation in Ocala sand
pine and its implications. Silvae Genetica 29(1):18-22.
Taras, M. A. 1980. Aboveground biomass of Choctawhatchee sand pine in
northeast Florida. USDA For. Serv. Res. Paper SE-210. 23 p.
English to Metric Conversion Factors
Multiply By To Obtain
Inches 2.540 Centimeters
Feet 0.3048 Meters
Cubic Feet 0.02832 Cubic Meters
Pounds 0.4536 Kilograms
Tons 0.9072 Metric Tons
Metric equivalents of the OSP and CSP tree prediction equations in
Tables 4, 5, and 6 are presented in Appendices 1, 2, and 3, respectively.
Appendix 1
Metric combined variable Ocala sand pine tree weight and volume
prediction equations for 20 components.
Equation Parameters"
Component Y b, b, R2
Stem Wood
Vol. I.B.
Green Wt.
Dry Wt.
Stem Bark
Green Wt.
Dry Wt.
Stem
Vol. O.B.
Green Wt.
Dry Wt.
Branch Wood
Green Wt.
Dry Wt.
Branch Bark
Green Wt.
Dry Wt.
Branch
Green Wt.
Dry Wt.
Foliage
Green Wt.
Dry Wt.
Crown
Green Wt.
Dry Wt.
Tree
Green Wt.
Dry Wt.
dm3 0.9420 .017023 .990
kg 1.3152 .015496 .987
kg 0.5488 .007188 .976
kg 0.6282 .001824 .947
kg 0.3281 .001014 .941
dm3 1.7326 .019328 .991
kg 1.9433 .017320 .987
kg 0.8768 .008202 .978
kg 1.7410 .005865 .758
kg 0.7068 .002666 .767
kg 0.7010 .001583 .739
kg 0.3198 .000530 .581
kg 2.4420 .007448 .760
kg 1.0266 .003197 .754
kg 2.5090 .002248 .494
kg 0.9830 .000861 .481
kg 4.9509 .009696 .708
kg 2.0096 .004058 .711
kg 6.8943 .027016 .938
kg 2.8864 .012259 .945
"Equation format: Y = b, + b,*DBH2*TH with DBH in cm and TH in m.
Appendix 2
Metric combined variable Choctawhatchee sand pine tree weight and
volume prediction equations for 20 components.
Equation Parameters"
Component Y bo b, R2
Stem Wood
Vol. I.B.
Green Wt.
Dry Wt.
Stem Bark
Green Wt.
Dry Wt.
Stem
Vol. O.B.
Green Wt.
Dry Wt.
Branch Wood
Green Wt.
Dry Wt.
Branch Bark
Green Wt.
Dry Wt.
Branch
Green Wt.
Dry Wt.
Foliage
Green Wt.
Dry Wt.
Crown
Green Wt.
Dry Wt.
dm3 3.0530 .014175 .966
kg 2.3152 .014719 .983
kg 0.9389 .007179 .984
1.3849 .001819 .924
0.7006 .000914 .906
dm3 4.7142 .016547 .975
kg 3.7001 .016538 .985
kg 1.6395 .008093 .988
kg 4.6349 .005477 .685
kg 1.9402 .002471 .670
kg 1.2239 .001035 .656
kg 0.3879 .000514 .686
kg 5.8588 .006512 .684
kg 2.3281 .002985 .686
kg 4.3808 .003621 .564
kg 1.6415 .001437 .577
kg 10.2396 .010133 .645
kg 3.9696 .004421 .665
Tree
Green Wt. kg 13.9400 .026671 .908
Dry Wt. kg 5.6091 .012514 .938
Equation format: Y = b, + b,*DBH2*TH with DBH in cm and TH in m.
Appendix 3
Metric allometric Ocala (OSP) and Choctawhatchee (CSP) sand pine
tree weight prediction equations for 10 crown components.
Equation Parameters"
Component Y b, b, b, R2
------------------------ ----------------OSP ----- ------------------
Branch Wood
Green Wt.
Dry Wt.
Branch Bark
Green Wt.
Dry Wt.
Branch
Green Wt.
Dry Wt.
Foliage
Green Wt.
Dry Wt.
Crown
Green Wt.
Dry Wt.
kg 0.27091 3.6022 -2.0791 .872
kg 0.11014 3.3528 -1.7905 .865
kg 0.10402 2.8563 -1.4069 .872
kg 0.07394 2.4272 -1.2576 .775
kg 0.38043 3.3579 -1.8661 .880
kg 0.17127 3.0444 -1.5750 .868
kg 1.11592 3.3014 -2.5721 .820
kg 0.50636 3.3292 -2.6709 .798
kg 1.26305 3.3270 -2.1840 .870
kg 0.54794 3.1448 -2.0211 .855
------------- -------------------P -- --SP------ ------------------
Branch Wood
Green Wt.
Dry Wt.
Branch Bark
Green Wt.
Dry Wt.
Branch
Green Wt.
Dry Wt.
Foliage
Green Wt.
Dry Wt.
Crown
Green Wt.
Dry Wt.
kg 0.45934 3.2899 -2.0428
kg 0.18938 3.3270 -2.0593
kg 0.22194 2.7407 -1.7957
kg 0.08472 2.6751 -1.6877
kg 0.66355 3.1762 -1.9940
kg 0.26749 3.1982 -1.9887
kg 0.45832 3.1225 -1.9802
kg 0.16847 3.0645 -1.8928
kg 1.11361 3.1593 -1.9900
kg 0.43084 3.1576 -1.9574
aEquation format: Y = bl*DBHb2*THba with DBH in cm and TH in m.
ll UNIVERSITY OF FLORID Ij
This publication was produced at a cost of $859.15, or 57.3 cents per copy,
to measure weight and volume components of sand pine trees.
All programs and related activities sponsored or assisted by the Florida
Agricultural Experiment Station are open to all persons regardless of race,
color, national origin, age, sex, or handicap.
ISSN 0096-607X
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