Session 6 ic2011 dykstra

Quality of Douglas-fir Lumber
from Thinnings
Designed to Improve Habitat
for Endangered Species
Dennis P. Dykstra
Research Forest Products Technologist (Retired)
PNW Research Station, USFS

USDA Forest Service, PNW Research Station

Presentation Outline
 Siuslaw National Forest
 Even-aged management issues

 Focus on improving habitat for
endangered species
 STUDS research project
 Wood-quality research questions

 Data collection

 Simulated sawing of logs

 Analysis of lumber quality and value

 Management implications of results
from the research


Siuslaw National Forest, Oregon
 Mid- to late-20th Century:
emphasis on clearcutting and
planting Douglas-fir
 Little diversity in age, species,
structure; increase in pests
 Current emphasis: habitat for
spotted owl, marbled
murrelet; increase diversity
 Aim is uneven-aged stands
with multiple species, larger
trees with large limbs, variable
understory

Siuslaw National Forest, Oregon
 Mid- to late-20th Century:
emphasis on clearcutting and
planting Douglas-fir
 Little diversity in age, species,
structure; increase in pests
 Current emphasis: habitat for
spotted owl, marbled
Hollingsworth, US F&WS

murrelet; increase diversity
 Aim is uneven-aged stands
with multiple species, larger
trees with large limbs, variable
understory

STUDS Project
 Siuslaw Thinning and Understory Planting
for Diversity Study
 Cooperative study (Siuslaw NF, Oregon
State University, PNW Research Station)
 Three research sites, each involving:
 Untreated control plot (1 ac)

 Heavy thinning plots (2 x 1 ac)

 Moderate thinning plots (2 x 1 ac)

 Light thinning plots (2 x 1 ac)

 Thinning treatments were both with and
without underplanting

STUDS Project
 Stands clearcut early 1960s, treated with
prescribed fire and herbicides, then planted
 Precommercially thinned in the mid-1970s
 STUDS Phase I commercial thinnings 1992-
1993: stocking reduced from 223-277 trees/ac
to 30, 60, 100 trees/ac
 Residual trees in plots given ID numbers,
measured at years 0, 4, 8 and spring 2008
 Phase II thinnings 2008-2009: further reduced
the plots with 60 and 100 trees/ac to densities of
about 30 and 50 trees/ac respectively


STUDS Project—Wood Quality Study
 Is wood quality significantly reduced
by thinnings designed to enhance
habitat for endangered species?
 Are there differences due to thinning
intensity?
 Are there differences between sites?
 Is there an effect due to the slope
aspect on which the trees are grown?
 Are knots (i.e., branches) uniformly
distributed around the stems of trees
in the target area?


STUDS 2008-09 (Phase II) Thinning
 2028 trees removed
from the three sites Yachats Site

 Sample for wood-
quality study: 3% of
thinned trees + 5 = 66
trees (Yachats: 27)
 Random sample
stratified by 4” Dbh
class
 All sample trees
yarded with cable
systems

STUDS Project—Log Tracking

Pre-Harvest

Y2 = Yachats
Treatment 2

White ribbon

Tree ID = 1611

Label with Y2-1611
Paint at
breast height

Metal tree tag
(1611) and
checked ribbon



Pre-Harvest Felling

Y2 = Yachats
Treatment 2

White ribbon

Tree ID = 1611

Label with Y2-1611
Paint at
breast height

Metal tree tag
(1611) and
checked ribbon



Pre-Harvest Felling Bucking

Y2 = Yachats
Treatment 2

White ribbon

Tree ID = 1611

Label with Y2-1611
Paint at
breast height

Metal tree tag
(1611) and
checked ribbon


Effectiveness of Log Tracking

 66 sample trees felled
 184 sample logs bucked
from the sample trees
 179 sample logs tracked
successfully to the landing
 5 lost sample logs were all
top logs with SED < 4 inches
 1 sample log arrived at the
landing with unreadable tags
but was identified using data
recorded during bucking

Log Profiles & Surface Defects

Spray paint,
hatchet, clipboard
Sweep offset at point
Measuring tape of maximum sweep Offset to knot

Chalk line running
between log ends

Log ID label (one on
each end of log)
Measured knots
Pith
painted white
Orientation line for
top and bottom
Log longitudinal axes
Peavy for
label
rolling logs


Log and knot summary

Butt 2nd 3rd
Attribute All logs logs logs logs
Logs 179 66 66 47
Log LED, in 13.0 18.2 12.6 9.9
Log SED, in 9.4 12.7 8.7 5.9
Log length, ft 31.08 36.59 32.52 21.32
Knots 10,970 3,904 4,627 2,439
Knots/ft 2.0 1.6 2.2 2.4


Simulated Sawing with AUTOSAW
 AUTOSAW—published by the New Zealand
Forest Research Institute, 1994
 Improvement on earlier FRI sawing simulators
 Lumber recovery and grades estimated according
to sweep, crook, wane; knot position, size, and
frequency; other defects not considered
 Adapted for WWPA Douglas-fir grades ~2000
(PNW Research Station and NZ-FRI)
 Written for the MS-DOS operating system; runs
in a DOS window in Windows XP but not in Vista
or Windows 7


AUTOSAW Data Requirements
 Mill-length logs only (< 21 ft = 6400 mm)
 Sawing data:
 headrig & edger kerf
 carriage dimensions
 nominal and actual widths & thicknesses
 trim lengths

 3-dimensional data for each log:
 Diameters at each profile point
 Sweep and crook offsets
 Location of each whorl along the log length
 Branch data for each whorl (number of branches,
location of each surface knot, radius of knot, rake
angle of branch)


3D Geometry—Bucking Logs


AUTOSAW Results
WWPA Rule Autosaw Grade
Joists & Planks A SelStr J&P
Autosaw Lumber summary by piece size:
Joists & Planks B No1 J&P
Lumber Production Report Size Pieces Volume Pct 2-in Joists & Planks C No2 J&P
2x4 180 1354.67 98.4% Joists & Planks D No3 J&P
Lumber produced from: 2x6 43 643.00 Joists & Planks E Econ J&P
Short logs from Cataract 2 2x8 52 1137.33 LtFrame&Studs F Const LF
2 x 10 49 1368.33 LtFrame&Studs G Std LF
Date of preparation of this report: 2 x 12 51 1804.00 Pct 1-in LtFrame&Studs H Util LF
Friday, January 14, 2011 1x4 21 78.33 1.6% LtFrame&Studs I Econ LF
1x6 4 24.00 LtFrame&Studs J Stud
LtFrame&Studs K Econ Stud
1x8 0 0.00
SpecDim L Scaffold1
1 x 10 0 0.00
SpecDim M Scaffold2
1 x 12 0 0.00
StrLtFraming N SelStr SLF
Totals 400 6,409.67 StrLtFraming O No1 SLF
StrLtFraming P No2 SLF
Lumber Thickness, Autosaw StrLtFraming Q No3 SLF
Log ID Piece ID in Width, in Len, ft Grade Board Feet WWPA Grade StrLtFraming R Econ SLF
C2-1009-1-1 7A 2 4 18 N 12.00 SelStr SLF Common 1 Com1
C2-1009-1-1 6A 2 8 18 D 24.00 No3 J&P Common 2 Com2
C2-1009-1-1 5A 2 8 18 A 24.00 SelStr J&P Common 3 Com3
C2-1009-1-1 4A 2 4 8 N 5.33 SelStr SLF Common 4 Com4
C2-1009-1-2 8A 2 6 18 D 18.00 No3 J&P Common 5 Com5
C2-1009-1-2 7A 2 6 18 E 18.00 Econ J&P
C2-1009-1-2 6A 2 4 9 Q 6.00 No3 SLF
C2-1009-2-1 6A 2 4 14 N 9.33 SelStr SLF
C2-1009-2-1 5A 2 6 14 B 14.00 No1 J&P
C2-1009-2-1 4A 2 4 10 N 6.67 SelStr SLF
C2-1009-2-2 7A 2 4 14 O 9.33 No1 SLF
C2-1009-2-2 6A 2 4 9 P 6.00 No2 SLF
C2-1009-2-3 4A 2 4 9 N 6.00 SelStr SLF
C2-1013-1-1 11A 2 4 8 O 5.33 No1 SLF
C2-1013-1-1 10A 2 10 16 C 26.67 No2 J&P


Lumber Grade by Log Position


Knot Density per Tree
4.0
Trees on South-Facing Slopes
3.5 Trees on North-Facing Slopes
Cataract
Yachats
Knots per Foot of Merchantable Height

3.0 Wildcat

2.5

2.0

1.5

1.0

0.5

0.0
8 10 12 14 16 18 20 22 24 26
Tree Diameter at Breast Height, inches


Lumber Value Recovery by Tree
350
Lumber Value by Tree
Cataract Observed Values
300 Wildcat Observed Values
Lumber Value, $/CCF Total Log Volume

Yachats Observed Values

250

200

150

100

50

0
6 8 10 12 14 16 18 20 22 24 26

Tree Diameter at Breast Height, inches


Management Implications
 Preliminary conclusions: analysis is incomplete
 Apparently no statistical difference in quality of
lumber from trees removed in the second
treatment of light and moderate thinnings
 Apparently no significant site effect
 Possibly a slightly higher density of knots in
logs from trees grown on south-facing slopes
 Knots are not uniformly distributed around the
tree bole; higher density toward the south
 Thinnings do no major harm to wood quality


Session 6 ic2011 dykstra

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