2409.12_10 - USDA Forest Service

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2409.12_10
Page 1 of 3
FOREST SERVICE HANDBOOK
JUNEAU, ALASKA
FSH 2409.12 – TIMBER CRUISING HANDBOOK
CHAPTER 10 – PRINCIPLES OF MEASURING TREES
Supplement No.: R-10 2409.12-2005-2
Effective Date: August 17, 2005
Duration: Effective until superseded or removed
Approved: /s/ Dennis E. Bschor
DENNIS E. BSCHOR
Regional Forester
Date Approved: 08/02/2005
Posting Instructions: Supplements are numbered consecutively by Handbook number and
calendar year. Post by document name. Remove entire document and replace with this
supplement. Retain this transmittal as the first page of this document. The last supplement to
this Handbook was R-10 Supplement 2409.12-2005-1 to 2409.12_60.
New Document(s):
2409.12_10
3 Pages
Superseded Document(s) by
Issuance Number and
Effective Date
2409.12_10 (2409.12-2004-1, 2/27/2004)
2 Pages
Digest:
14.12m - Corrects bark thickness ratio in Example 2.
Adds a table (14.12m – Exhibit 01) that converts DBH to stump diameter.
R-10 SUPPLEMENT 2409.12-2005-2
EFFECTIVE DATE: 08/17/2005
DURATION: Effective until superseded or removed
2409.12_10
Page 2 of 3
FSH 2409.12 – TIMBER CRUISING HANDBOOK
CHAPTER 10 – PRINCIPLES OF MEASURING TREES
14 – MEASURING THE TREE
14.12m – Trees without Bark
For trees without bark, use the following bark thickness ratios to calculate Diameter at Breast
Height (DBH).
Species
Spruce
Hemlock
Western Red Cedar
Alaska Yellow Cedar
Bark Thickness Ratio
.96
.92
.95
.95
DBH = Diameter without bark/bark thickness ratio.
1. Example 1:
A spruce tree has no bark at DBH (4.5 feet) above root collar and its diameter is 30.6 inches.
Divide 30.6 by .96 and record DBH as 31.9 inches.
2. Example 2:
A dead Alaska yellow cedar tree has no bark at DBH (4.5 feet) above root collar and its diameter
is 8.7 inches. Divide 8.7 by .95 and record DBH as 9.2 inches.
See 14.12m – Exhibit 01 for a table that converts DBH to stump diameter.
14.2 – Measuring Tree Heights
Use total tree height when measuring tree heights. Measure from one-foot stump height on the
high ground side to the tip of the tree leader. When the tree leader is missing, project the height.
Record total tree heights to the nearest foot.
Tree heights recorded in number of logs are not acceptable.
R-10 SUPPLEMENT 2409.12-2005-2
EFFECTIVE DATE: 08/17/2005
DURATION: Effective until superseded or removed
2409.12_10
Page 3 of 3
FSH 2409.12 – TIMBER CRUISING HANDBOOK
CHAPTER 10 – PRINCIPLES OF MEASURING TREES
14.12m – Exhibit 01
Stump Diameters outside bark at 1.0 feet above root collar given DBH
DBH
9
10
11
12
13
14
15
16
17
18
19
20
21
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24
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42
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44
45
46
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53
54
55
56
57
58
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60
Sitka Spruce
11
12
13
14
15
17
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31
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61
62
63
64
65
65
Stump Diameters (ob) at 1.0 feet above root collar
Hemlock
Alaska Yellow Cedar
Western Red Cedar
10
11
12
11
12
13
12
14
14
14
15
15
15
16
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17
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27
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35
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47
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51
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52
51
54
52
55
54
56
55
57
56
58
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58
61
59
62
61
63
62
64
63
65
64
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65
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67
70
Dark line indicates extent of collected data
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