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The Value of an
Old-Growth Tree |
This document assesses the value of a hollow bearing tree for its hollow
bearing characteristics only; it does not take into account such values as:
food source to wildlife, nesting opportunities for nest building birds,
ground stabilization, water runoff mitigation, carbon dioxide consumption,
shade value, historic or aesthetic value.
This document is the educated opinion only of the author and should be taken
as such for further information other expert opinions should be sought.
A 10 year old tree can support one small nest box such as those used by
lorikeets, micro bats or sugar/squirrel gliders provided that the habitat is
either intact or has been rehabilitated. For each subsequent 10 years of
growth another nest box may be added to the tree.
In the wild it is reasonable to assume that a two hundred year old tree
could have in excess of 20 hollows of various sizes it would be feasible
therefore to suppose that one hollow would be added for each 10 years of
life It would of course not be necessary to place nest boxes in a tree of
this age as the nest holes would be well established within the trunk and
branches of the tree.
However, if you had to replace this hollow tree with recruits without
hollows (at least for the first 200 years of life) then you would need to
hang a single box in 20 replacement trees for a period of at least 200
years. Boxes would need to be replaced every 10 years to ensure quality of
the hollow habitat.
The formula:
 If the
approximate age of the tree is 200 years then we consider it to be
equivalent to 20 nest boxes at an average price of $100/box = $2000.00.
Each nest
box will need to be replaced every 10 years.
If we
plant the same species of tree in the same area given correct growing
conditions we can expect that in 200 - 300 years the nest boxes will be
replaced by natural hollows** or if we leave the tree in place it will live
for at least another 300 years.
Average
Price of Installed nest box ($100) x (approximate age of tree ÷ 10) x number
of years until new tree replaces old one or tree will live (say 300) @2%
inflation per annum
Therefore the value of the tree in terms of nest box replacement is
$2,838,515.77 over a life of 300 years!
|
Year |
Average
$ price of single installed Nest Box |
Total $ cost of 20 Nest Boxes |
|
1 |
100.00 |
2000.00 |
|
10 |
120.00
|
2400.00 |
|
20 |
144.00 |
2880.00 |
|
30 |
172.80 |
3456.00 |
|
40 |
207.36 |
4147.20 |
|
50 |
248.83 |
4976.64 |
|
60 |
298.60 |
5971.97 |
|
70 |
358.32 |
7166.36 |
|
80 |
429.99
|
8599.63 |
|
90 |
515.98 |
10319.56 |
|
100 |
619.17 |
12383.47 |
|
110 |
743.01 |
14860.17 |
|
120 |
891.61 |
17832.20 |
|
130 |
1069.93 |
21398.64 |
|
140 |
1283.92 |
25678.37 |
|
150
|
1540.70 |
30814.04 |
|
160 |
1848.84 |
36976.85 |
|
170 |
2218.61 |
44372.22 |
|
180 |
2662.33 |
53246.66 |
|
190 |
3194.79 |
63895.99 |
|
200 |
3833.75 |
76675.19 |
|
210 |
4600.51 |
92010.23 |
|
220 |
5520.61 |
110412.28 |
|
230 |
6624.73 |
132494.74 |
|
240 |
7949.68 |
158993.69 |
|
250 |
9539.62 |
190792.43 |
|
260 |
11447.54 |
228950.91 |
|
270 |
13737.05 |
274741.10 |
|
280
|
16484.46 |
329689.32 |
|
290
|
19781.35 |
395627.18 |
|
300 |
23737.63 |
474752.62 |
|
Total Cost: |
$2,838,515.77 |
Please Note:
**
Attrition rates would have to be taken into account here, we recommend
that 10 trees be planted to compensate for the loss of one tree.
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