HOW FAST DO YOUNG PLANTATIONS ADD WOOD VOLUME?
Although we often hear this question, the answer became especially interesting when a PPIC( landowner asked for the price to buy back his trees on 30 March 1998, when the trees had completed their ninth growing season. The formula for calculating this is set in the contract, and the price depends solely on our costs, the specified interest rate, and the inflation rate according to the CPI-U. But we got curious about what sort of investment the landowner was making, so we used PTAEDA2V to predict the stand on that day, BEFORE the start of its tenth growing season, as follows:
|
INPUTS PREDICTED |
|
Site Index = 80.0
Growing Seasons Completed = 9.0
Planted Trees = 529.5
Percent Hardwood = .0 |
Dominant Height = 33.2
Average DBH = 6.2
Average Height = 32.2
Average Crown Ratio = 65.4 |
| |
|
|
|
Total |
Volume |
Volume |
|
DBH |
Number |
Average |
Basal |
Volume |
Cords |
Doyle |
|
Class |
Trees |
Height |
Area |
o.b. |
To 4 in. |
Bd. Ft. |
|
1 |
1.3 |
16.3 |
.0 |
.4 |
.0 |
.0 |
|
2 |
2.6 |
19.8 |
.1 |
1.1 |
.0 |
.0 |
|
3 |
17.2 |
24.8 |
.9 |
14.0 |
.0 |
.0 |
|
4 |
37.1 |
28.1 |
3.4 |
50.3 |
.0 |
.0 |
|
5 |
67.5 |
31.0 |
9.5 |
148.2 |
1.2 |
.0 |
|
6 |
127.1 |
32.5 |
25.1 |
399.2 |
3.7 |
.0 |
|
7 |
132.4 |
33.6 |
34.8 |
562.1 |
5.6 |
.0 |
|
8 |
47.7 |
34.7 |
16.1 |
264.6 |
2.7 |
.0 |
|
9 |
18.5 |
35.0 |
7.9 |
131.2 |
.2 |
.0 |
|
Total |
451.4 |
|
97.9 |
1571.0 |
13.3 |
.0 |
As you can discover in Jim Vardaman's "How To Make Money Growing Trees," on average tree growth starts on April 1 and ends on September 30 each year, so PTAEDA2V predicted that the volumes on 30 September 1998 would be as follows:
|
INPUTS PREDICTED |
|
Site Index = 80.0
Growing Seasons Completed = 9.0
Planted Trees = 529.5
Percent Hardwood = .0 |
Dominant Height = 37.5
Average DBH = 6.6
Average Height = 36.1
Average Crown Ratio = 61.1 |
| |
|
|
|
Total |
Volume |
Volume |
|
DBH |
Number |
Average |
Basal |
Volume |
Cords |
Doyle |
|
Class |
Trees |
Height |
Area |
o.b. |
To 4 in. |
Bd. Ft. |
|
2 |
4.0 |
21.3 |
.1 |
1.6 |
.0 |
.0 |
|
3 |
9.3 |
27.6 |
.5 |
8.5 |
.0 |
.0 |
|
4 |
33.1 |
30.9 |
3.1 |
49.8 |
.0 |
.0 |
|
5 |
41.0 |
34.0 |
5.7 |
97.6 |
.8 |
.0 |
|
6 |
103.3 |
35.4 |
20.4 |
351.7 |
3.3 |
.0 |
|
7 |
133.7 |
37.3 |
35.9 |
639.5 |
6.4 |
.0 |
|
8 |
92.7 |
38.4 |
31.9 |
579.2 |
5.9 |
.0 |
|
9 |
25.2 |
38.9 |
11.1 |
202.6 |
.3 |
.0 |
|
10 |
9.3 |
39.8 |
4.8 |
89.8 |
.1 |
52.1 |
|
Total |
451.4 |
|
113.6 |
2020.3 |
16.8 |
52.1 |
Notice the differences that six months made. Although the increases were only 13% for heights and 6% for DBH, they were 29% for cubic-foot volume and 26% for pulpwood volume.
If the landowner holds his trees for another year until 30 September 1999, PTAEDA2V predicts that his stand will be as follows:
|
INPUTS PREDICTED |
|
Site Index = 80.0
Growing Seasons Completed = 9.0
Planted Trees = 529.5
Percent Hardwood = .0 |
Dominant Height = 41.5
Average DBH = 7.0
Average Height = 39.9
Average Crown Ratio = 57.2 |
| |
|
|
|
Total |
Volume |
Volume |
|
DBH |
Number |
Average |
Basal |
Volume |
Cords |
Doyle |
|
Class |
Trees |
Height |
Area |
o.b. |
To 4 in. |
Bd. Ft. |
|
2 |
4.0 |
23.2 |
.1 |
1.7 |
.0 |
.0 |
|
3 |
5.3 |
30.8 |
3.5 |
.5 |
.0 |
.0 |
|
4 |
25.2 |
33.5 |
2.3 |
39.9 |
.0 |
.0 |
|
5 |
35.7 |
36.0 |
4.9 |
87.0 |
.7 |
.0 |
|
6 |
74.1 |
38.6 |
14.7 |
274.8 |
2.6 |
.0 |
|
7 |
117.8 |
40.2 |
31.6 |
605.6 |
6.1 |
.0 |
|
8 |
116.5 |
41.8 |
40.2 |
792.1 |
8.0 |
.0 |
|
9 |
50.3 |
43.0 |
21.7 |
436.5 |
.4 |
68.6 |
|
10 |
19.9 |
43.2 |
10.7 |
214.6 |
.6 |
287.7 |
|
11 |
2.6 |
45.8 |
1.6 |
34.7 |
.0 |
66.9 |
|
Total |
451.4 |
|
128.1 |
2492.4 |
18.3 |
423.2 |
In this year's growing season, cubic-foot volume will increase 23%, pulpwood volume 9%, and sawtimber volume 712%. Since per-unit values of pulpwood and sawtimber increase with DBH (see prices on www.vardaman.com), his investment will be one of the best available anywhere. We would be pleased to maintain our ownership.
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