THE LELAND SPEED PLANTATION AT AGE 12
On 29 September 1992 we remeasured the research plots in the Leland Speed
Plantation (LSP) after 12 growing seasons on the site and discovered that
clearing of a nearby powerline right of way and bark beetles spreading from
it had eliminated the usefulness of Plot D. Analysis of the other three
by scientists at Virginia Tech once again revealed that Research Plot C
was most typical of the stand. If it is a representative sample, here is
the average per-acre stand today:
|
DBH Class
|
Number Trees
|
Average Height
|
Basal Area
|
Cu. Ft.
|
Cords To 4.in
|
bd.ft. Doyle
|
|
4
|
11.0
|
38.0
|
1.0
|
20
|
.0
|
0
|
|
5
|
12.7
|
42.0
|
1.7
|
36
|
.3
|
0
|
|
6
|
28.9
|
45.7
|
5.7
|
124
|
1.2
|
0
|
|
7
|
47.6
|
48.3
|
12.8
|
293
|
2.9
|
0
|
|
8
|
54.4
|
50.4
|
19.1
|
450
|
4.6
|
0
|
|
9
|
58.6
|
52.1
|
25.5
|
621
|
6.4
|
0
|
|
10
|
41.6
|
53.4
|
23.1
|
574
|
1.3
|
879
|
|
11
|
36.5
|
54.4
|
23.6
|
595
|
2.0
|
838
|
|
12
|
9.3
|
55.0
|
7.1
|
180
|
.4
|
328
|
|
13
|
.8
|
60.1
|
.8
|
21
|
.0
|
54
|
|
TOTAL
|
301.8
| |
120.4
|
2914
|
19.0
|
2099
|
Readers who want a detailed comparison of today's trees with those at age
10 should see our issue of 15 January 1991. In summary, however, comparable
figures then were number of trees = 310.4, basal area = 97.5 square feet,
total volume = 2018 cubic feet, cords to a 4-inch top = 15.5, and Doyle
scale sawtimber volume = 820. Comparable figures at age 8 appear in our
issue of 15 April 1989.
As the first step in deciding what management plan to follow, we calculated
Mr. Speed's income from clearcutting the stand now to be as follows:
|
DBH Class
|
Cords / MBF
|
Unit Value
|
Total Value
|
|
5
|
0.3
|
$ 12
|
$ 3.60
|
|
6
|
1.2
|
14
|
16.80
|
|
7
|
2.9
|
17
|
49.30
|
|
8
|
4.6
|
20
|
92.00
|
|
9
|
6.4
|
25
|
160.00
|
|
10
|
1.3
|
25
|
32.50
|
|
11
|
2.0
|
25
|
50.00
|
|
12
|
0.4
|
25
|
10.00
|
|
13
|
.879
|
165
|
145.04
|
|
14
|
.838
|
175
|
146.65
|
|
15
|
.328
|
200
|
65.60
|
|
16
|
.054
|
225
|
12.15
|
| TOTAL |
783.64
|
| Less 5.4 % selling expense |
42.32
|
| Net Cash |
741.32
|
The first alternative that we tested was to thin the stand now to remove
inferior trees of all sizes and enough smaller suitable trees to reduce
basal area per acre to 80 square feet and then to clearcut the stand at
age 22. We estimated the volume and value of trees to be thinned now to
be as follows:
|
DBH Class
|
Number Trees
|
Cords to 4"
|
Unit Value
|
Total Value
|
|
4
|
11.0
|
|
$ 0
|
$ 0
|
|
5
|
12.7
|
0.3
|
12
|
3.60
|
|
6
|
28.9
|
1.2
|
14
|
16.80
|
|
7
|
38.3
|
2.3
|
17
|
39.10
|
|
8
|
12.7
|
1.1
|
20
|
22.00
|
|
9
|
7.6
|
0.9
|
25
|
22.50
|
|
10
|
9.3
|
1.3
|
25
|
32.50
|
|
11
|
11.9
|
2.0
|
25
|
50.00
|
|
12
|
1.7
|
0.4
|
25
|
10.00
|
| TOTAL |
196.50
|
| Less 10 % selling expense |
19.65
|
| Net Cash |
176.85
|
The estimated stand after thinning is as follows:
|
DBH Class
|
Number Trees
|
Average Height
|
Basal Area
|
Total Volume
Cu. Ft.
|
Volume Cords To 4.in
|
Volume bd.ft. Doyle
|
|
7
|
9.3
|
48.2
|
2.8
|
63
|
0.6
|
0
|
|
8
|
41.6
|
50.1
|
14.6
|
342
|
3.5
|
0
|
|
9
|
51.0
|
52.1
|
22.1
|
538
|
5.5
|
0
|
|
10
|
32.3
|
53.3
|
18.1
|
447
|
0
|
879
|
|
11
|
24.6
|
54.1
|
15.9
|
399
|
0
|
838
|
|
12
|
7.6
|
54.8
|
5.7
|
146
|
0
|
328
|
|
13
|
0.8
|
60.1
|
0.8
|
21
|
0
|
54
|
|
TOTAL
|
167.4
| |
79.9
|
1956
|
9.7
|
2099
|
Estimated volume and value of trees clearcut at age 22 are as follows:
|
DBH Class
|
Number Trees
|
Average Height
|
Basal Area
|
Total Volume
Cu. Ft.
|
Volume Cords To 4.in
|
Volume Doyle MBF
|
Unit Value
|
Volume bd.ft. Doyle
|
|
9
|
4.3
|
71.7
|
1.9
|
64
|
0.7
| |
$ 25
|
$ 17.50
|
|
10
|
17.0
|
77.1
|
9.4
|
334
|
0
|
.766
|
165
|
126.39
|
|
11
|
42.5
|
79.9
|
28.2
|
1042
|
0
|
2.657
|
175
|
464.75
|
|
12
|
32.3
|
83.1
|
25.3
|
969
|
0
|
2.736
|
200
|
547.20
|
|
13
|
27.2
|
83.6
|
25.4
|
980
|
0
|
3.043
|
225
|
684.68
|
|
14
|
27.2
|
85.3
|
29.0
|
1140
|
0
|
3.832
|
235
|
900.52
|
|
15
|
13.6
|
86.4
|
16.9
|
671
|
0
|
2.464
|
235
|
579.04
|
|
16
|
2.5
|
87.1
|
3.4
|
138
|
0
|
.531
|
235
|
124.79
|
|
17
|
0.8
|
93.6
|
1.3
|
56
|
0
|
.243
|
235
|
57.11
|
|
167.4
| |
140.8
|
5394
|
0.7
|
16.272
| |
3201.98
|
| Less 5.4 % selling expense |
172.91
|
| Net Cash |
3029.07
|
To compare our proposed plan with other possibilities, we calculated its
net present value by discounting to the present the clearcut value at age
22 ($3,029.07) at 7% compound interest and added this sum ($1,539.83) to
the thinning yield of $176.85 to obtain a total of $1,716.68. Since this
far exceeds the net present value of $741.32 obtained by clearcutting now,
it is clearly advantageous to hold some of the stand for future growth.
We followed the same procedures to evaluate thin-at-13-harvest-at-23 and
thin-at-14-harvest-at-24. Net present value of 13-23 was $1,884.28; that
of 14-24 was $1,823.19. Since the 13-23 value is only 9.8% above the 12-22
value and since bark-beetle populations were increasing and had already
caused some damage, we believed that the premium for waiting was not large
enough for the risks involved. We therefore recommended that Mr. Speed adopt
the 12-22 plan for the LSP and also clearcut eight acres of natural stands
on another portion of the tract.
After he approved, we marked all trees to be removed and sold them in a
sealed-bid sale. Stumpage prices in the preceding analyses came from this
sale. We will record the stands during and after cutting with a camcorder
and include the shots in our videotape now being produced. We will also
tally the trees remaining on all research plots, remeasure them every two
years, and report our findings in later issues. So far everything has worked
out close to our original predictions. Stay tuned.
|
