2090.11_1.41b_ex01
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FOREST SERVICE HANDBOOK
SOUTHWESTERN REGION (REGION 3)
ALBUQUERQUE, NEW MEXICO
FSH 2090.11 – ECOLOGICAL CLASSIFICATION AND INVENTORY HANDBOOK
CHAPTER 1 – ECOSYSTEM CLASSIFICATION
Supplement No.: 2090.11-93-2
Effective Date: October 21, 1993
Duration: This supplement is effective until superseded or removed.
Approved: LARRY HENSON
Regional Forester
Date Approved: 10/21/1993
Posting Instructions: Supplements are numbered consecutively by Handbook number and calendar
year. Post by document; remove the entire document and replace with this supplement. Retain this
transmittal as the first page(s) of this document. The last supplement to this Handbook was 2090.11-932 to chapter 1.
New Document(s):
2090.11_1.41b_ex01
2 Pages
Superseded Document(s) by
Issuance Number and
Effective Date
Digest:
1.41b - 1.41b - Exhibit 01 - This is a new exhibit that shows the minimum structural criteria for
determining old-growth candidate sites
R3 SUPPLEMENT 2090.11-93-2
EFFECTIVE DATE: 10/21/1993
DURATION: This supplement is effective until superseded or removed
2090.11_1.41b_ex01
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FSH 2090.11 – ECOLOGICAL CLASSIFICATION AND INVENTORY HANDBOOK
CHAPTER 1 – ECOSYSTEM CLASSIFICATION
1.41b - Exhibit 01
The Minimum Criteria for the Structural Attributes Used to Determine Old-growth.
FOREST COVER TYPE, NAME
FOREST COVER TYPE, SAF CODE
SITE CAPABILITY POTENTIAL
BREAK BETWEEN LOW AND HIGH SITE
SITE
1. LIVE TREES IN MAIN CANOPY
TREES/ACRE
DBH/DRC
AGE (YEARS)
2. VARIATION IN TREE DIAMETERS
(YES OR NO)
Interior
Ponderosa Pine
237
Pinyon-Juniper
239
LOW
12
9``
150
HIGH
30
12`
200
Aspen
217
Mixed-Species
Group
210, 211, 216, 219
50 Douglas-Fir
Edminster & Jump
LOW
HIGH
Engelmann Spruce
Subalpine Fir
206, 209
50 Engelmann Spruce
Alexander
LOW
55 Minor
LOW
HIGH
ALL
20
14``
20
14``
12
18``
150
16
20``
150
20
10``
140*/170**
180
20
18``
180
100
ND
ND
ND
ND
ND
ND
ND
ND
0.5*
9``
8'
1
10``
10'
1
14``
15'
1
14``
25'
ND
10``
ND
2.5
14``
20'
2.5
16``
25'
3
12``
20'
2
9``
8``
2**
10``
10'
2
12``
15'
2
12``
15'
ND
ND
ND
4
12``
16'
4
12``
16'
5
12``
16'
ND
ND
ND
ND
ND
ND
ND
ND
SS/MS
SS/MS
SS/MS
SS/MS
SS
SS/MS
6. TOTAL BA, SQUARE FEET/ACRE
6
24
70
90
ND
80
100
120
7. TOTAL CANOPY COVER,
PERCENT
20
35
40
50
50
50
60
60
3. DEAD TREES
STANDING
TREES/ACRE
SIZE, DBH/DRC
HEIGHT (FEET)
DOWN
PIECES/ACRE
SIZE (DIAMETER)
LENGTH (FEET)
4. TREE DECADENCE
TREES/ACRE
5. NUMBER OF TREE CANOPIES
SS/MS SS/MS
PINYON-PINE * Dead limbs help make up dead material deficit. ** Unless removed for firewood or fire burning activities.
SPRUCE-FIR * In mixed corkbark fir and Engelmann spruce stands where Engelmann spruce is less than 50 percent composition in the stand.
** In mixed corkbark fir and Engelmann spruce stands where Engelmann spruce is 50 or more percent composition in the stand. ND is not
determined; SS is single-storied; MS is multi-stories