Introduction to the FIA Down Woody Materials Indicator1st of 3 Part Training Series
Christopher Woodall
DWM National Indicator Advisor
Outline
• Indicator Updates
• What are Down Woody Materials?
• Why Collect DWM data?
• Sampling Design Theory
Indicator Updates
• No sample protocol changes
• Field manual updated
• Web-site updated
• DWM sample design and analysis in press – NC-GTR-256
• Web-based dissemination of data and wider use of data
Definition of DWM
Dead material within forests in various stages of decay such as fallen trees,
branches, and leaf litter
The FIA program places numerous forest ecosystem components into the
DWM Indicator
DWM ComponentsCoarse Woody Debris
Duff
Slash
Shrubs/Herbs
FineWoodyDebris
Litter
Coarse and Fine Woody Debris
Transect Diameter Class Name
0.00-0.24 inches Small FWD
0.25-0.99 inches Medium FWD
1.00-2.99 inches Large FWD
3.00+ inches CWD
Fuel-Hour Classes
Transect Diameter
Class Name Hour-Class
0.00-0.24 inches
Small FWD 1-hour
0.25-0.99 inches
Medium FWD 10-hour
1.00-2.99 inches
Large FWD 100-hour
3.00+ inches CWD 1000+-hour
Duff and Litter
“unrecognizable plant parts”
“dead plant material on forest floor surface”
Slash/Residue Piles
Piles of CWD
Shrub and Herbs
“Live and dead shrubs/herbs including
grass, herbaceous woody plants, and
vines”
Fuelbed
“Depth of the fuel’s complex, from forest
floor to the tallest fuel component”
Why collect DWM data?
• Indicator of Forest Health
• Wildlife Habitat
• Fuels Estimation
• Carbon Estimation
• Completes Life Cycle of Trees
Indicator of Forest Health
Soils
Crown Condition
Down Woody Materials
Ozone Injury
LichensVegetation
Structure and DiversityTree Damage
Wildlife
The DWM Inventory describes the amount and condition of wildlife habitat through estimation of coarse woody debris attributes.
Wildlife
0
200
400
600
800
1000
1200
1400
1600
1800
2000
Il IN IA KS MI MN MO NE ND SD WI
State
ft3 /a
cre
Mean estimates of CWD volumes for forests of the North Central Region
Wildlife
68%
17%
14%
1%
3.0-7.9 8.0-12.9 13.0-17.9 18.0+
Transect Diameter (in)A40%
1%
20%6%
33%
1 2 3 4 5
Decay ClassB
Proportions of coarse woody debris pieces per acre by transect diameter (A) and decay class (B) (1=least decayed, 5=most decayed), Indiana, 2001-2003
Fuels1-hr
10-hr
100-hr
Total Fine Woody Debris
Fire Science
0
5
10
15
20
25
30
35
1-hr 10-hr 100-hr 1000-hr Duff Litter
Fuel Classes
Ton
s/a
cre
NC States
Eco Prov 212
PRNL
BWCA Non-Blow Down
BWCA Blow Down
Estimates for DWM in
Boundary Waters Canoe
Area Compared to rest of region
Carbon Estimation
Estimates of Regional Carbon Pools for
Coarse Woody Debris
Estimates for International Treaties
and Criterion Indicators
DWM and National Inventory
Completes inventory of trees from living, to dead, to decomposed
Microplot Sapling
Sub-plot Tree
Sub-plot Standing
Dead
DWM Down and Dead
Summary of DWM Components
DWM Sampling Theory
DWM diversity requires a diversity of sampling methods
DWM Component
Sampling Design
CWD, FWD Transect
Duff, Litter, Fuelbed
Simple Random Sampling at Specified Points in Sub-plot
Shrubs and Herbs
Micro-plot
Slash Piles Sub-plot
Sampling on the Sub-Plot
N
4 3
2
1
Microplot
Subplot
Slash Piles
Similar to sampling phase two trees, if a center of a slash pile
coincides with a subplot it is
considered an “in” slash pile
Sampling on the Sub-Plot
FIA Subplot
“out” slash pile“in” slash pile
Slash piles are sampled across all
four subplots
Sampling on the Microplot
6.8 ftRadius
In order to estimate shrub/herb heights and
coverage for forests (fuel ladders)
estimate shrub/herb heights and coverage
occurring on micro-plot
Depth Estimates on Subplot
Duff
Litter
Fuelbed
In order to estimate depth of duff, litter,
and the fuelbed on a subplot…
12 sample points located for measurement on
subplots
Depth Estimates on Subplots
4 3
2
1
Sample Locations
Transect Sampling
FWD and CWD pieces are not all counted within a given area
rather…
All FWD and CWD pieces that intersect a sampling plane are
tallied
Transect Sampling
Probability of match stick intersecting
randomly placed line related to number of sticks and length of
line
Transect Sampling Planes
Fuel Bed
IntersectingSampling
Plane
CWD Pieces
DWM Sample Protocol establishes 6 foot tall sampling transects that radiate from FIA subplot centers to intersect woody pieces
CWD and FWD Transects
Use 3 transects established on each subplot to sample CWD, one transect on each subplot to
sample FWD4
30°
150°
270°
30°
150°
270°
30°
150°
270°
30°
150°
270°
3
2
1
Bringing it all Together
Key
N
430°
150°
270°
30°
150°
270°
30°
150°
270°
30°
150°
270°
3
2
1
Transect Information
FWD < 0.25”& 0.26”-0.99”
FWD 1.00”-2.99”
CWD => 3.00”
6 ft. s.d.
10 ft. s.d.
24 ft. h.d.
s.d.= slope dist., h.d.=horizontal dist.
Sub-plot
Micro-plot
CWD Transect
FWD Transect
Distances between sub-plot points: 120 ft., Distance from sub-plot center and microplot center: 12 ft., Distance betweenSub-plot 1 and sub-plots 2, 3, and 4: 207.8 ft. at angles (degrees) 150, 210, and 270 respectively.
Conclusions
• The DWM indicator estimates numerous ecosystem components
• Data Crucial to Fire, Carbon, and Wildlife Sciences
• Integral Part of National FIA Program, Completes Tree Life Cycle
• Series of different sampling techniques for estimation of various DWM components applied to phase two plots
FIA’s Down Woody Materials Field Sampling Protocols2nd of 3 Part Training Series
Christopher Woodall
DWM National Indicator Advisor
Outline
• Transect Segmenting
• Coarse Woody Debris
• Fine Woody Debris
• Duff, Litter and Fuelbed
• Shrubs and Herbs
• Slash Piles
4
2
3
1
150
270
30
24 feet (h.d.)Three / subplot
CWD
20 ft (s.d.)
FWD (small & medium)
Subplot
14 ft (s.d.)
24ft(s.d.)
6 ft (s.d.)
10 ft (s.d.)
FWD (large)
One per subplot
Annular plot
6.8 ft. radius microplot
Duff, Litter, Fuelbed depths 24 ft. location, every transect
Transect Segmenting
1) Only sample DWM components on accessible forest land
2) Must map changes in forest condition classes along transects
Transect Segmenting
Non-ForestCC #2
10 ft
Transect length must equal 24 ft, Horizontal Dist.
Subplot
T CC BEGIN
SDIST
SLOPE
%
END SDIST
2 030 1 0.0 10 10.0
2 030 2 10.0 50 25.7
ForestCC #1
Coarse Woody Debris
Sampling Procedures Depend on Decay of Individual Pieces
Freshly Fallen
Moderate Decay Mostly Decayed
CWD Decay Classes
Decay Class Structural Integrity Texture of Rotten Portions
1Sound, intact, freshly fallen, bark
onIntact, no rot
2 SoundMostly intact, sapwood rotting and soft,
can’t pull off easily
3Heartwood sound, supports own
weight
Heartwood hard, rot beginning, large cubical rot pieces, sapwood easily
pulled off or missing
4Heartwood rotten, does not
support its own weight, but holds shape
Heartwood soft, small cubical decay pieces, metal pin easily pushed into
heartwood
5None! Spreads out on ground,
losing shape of logWood is soft, crumbly, heavily
decomposed, powdery when dry
CWD Tally Rules
Point of Intersection
Transect
Transect Diameter
CWD Piece Axis
Decay Classes 1 - 4
Piece >= 3” Transect Diameter
Piece >= 3’ Long
Decay Class 5
Piece >= 5” Transect Diameter
Piece >= 3’ Long
Piece >= 5” Above ground-level
CWD Tally Rules Cont’d
Only tally portion of log above ground and or above water
Standing dead trees are CWD if they lean >= 45 from vertical
Must have a diameter >= 3 inches along entire length
Tally a piece each time it intersects any transect, regardless of the
number of times
If log split down center, treat as two separate pieces
CWD Forks and Branches
Forked PiecesEach fork must meet minimum specsFork with largest diameter at the crotch is the ‘main bole’2nd fork ends at the crotch
Large branchBranch must meet minimum specsLength measured from small end to the point where it connects to main bole
CWD Measurements
Sub plot TRAN
CWD DIST SPP
TRAN DIAM
SML DIAM
LRG DIAM
TOT LENG
DECAY CLASS HOL?
CWD HIST
Decay Class
1-4
5
Length
Transect Diameter
CWD distance
Large End Diameter
Small End Diameter
Decay ClassSpeciesHollow?
CWD History
CWD Lengths and Diameters
Measure here
Measure here
Length is measured between diameter measurements
When the ends of the log are splintered or crumbling from decay…measure the diameter at the point where it best represents the overall volume of the log.
CWD LengthsSeparates if Pulled
CWD Length CWD Length
CWD Diameter
CWD Diameter
If CWD piece is fractured, either across diameter or length, and crew determines it would separate if pulled by either end… Then… Tally as two separate CWD pieces
Fine Woody Debris
SubplotCond. Class
Small FWD
Med. FWD
Large FWD
Reason High
RP Transect
1 1 003 002 007 0 0
Count FWD pieces, by size class, intersecting subplot transects
FWD Sample Design
150
270
30
Tallied on 150 degree transect on each subplot
20 ft (s.d.)
14 ft (s.d.)
24ft (s.d.)
6 ft (s.d.)
10 ft (s.d.)
Large FWD: Tally pieces 1” – 2.9”
Small FWD: Tally pieces < ¼ ”
Medium FWD: Tally pieces >= ¼ ” – .9”
Size-Class Tally Counts
FWD Tally Rules
• Estimate FWD tally after count > 50 for diameter < 1 inch
• Estimate FWD tally after count > 20 for diameter >= 1 inch
• Make attempt to tally FWD first due to trampling
• If count exceeds 100 in any size class indicate reason why (i.e. rat’s nest or fallen tree)
• If a pile intersects the FWD transect (14 – 24’) do not measure FWD (code ‘Yes’ for ‘RP_on_transect’)
Duff, Litter, and Fuelbed
Subplot Transect DL_SampDuff
DepthLitter Depth
Fuelbed Depth
1 150 1 inches inches feet
Depth of 3 fuel layers above mineral soil
Duff, Litter, and Fuelbed
Mineral Soil
Duff
Litter
CWD & FWDFuelbed Depth
Subplot
Measure depths at 24 ft (slope distance) on every transect.
Obstructions:If a rock or other obstruction is found at sample point, do not measure any depths.
If a log is found at sample point, measure fuelbed depth but NOT duff and litter.
Duff, Litter, Fuelbed
0
1
2
Duff and litter depth not sample, fuelbed sampled
All sampled
Nothing sampled
Use coding options to take quality measurements, since we measure these variables at twelve points on each plot, don’t collect data if measurement obstructed or compromised
Microplot Fuels
SubplotLive
Shrub %
Live Shrub
HT
Dead Shrub
%
Dead Shrub
HT
Live Herb
%
Live Herb HT
Dead Herb
%
Dead Herb HT
Litter %
1 30 4.0 10 2.2 90 1.9 0 0.0 40
10% Cover Classes
Microplot Sampling
Estimate coverage (%) and tallest height (ft) of live/dead shrubs/herbs on microplot
Estimate coverage (%) of litter on microplot
Microplot Sampling
Herbs
Herbs and Shrubs
Shrubs
Live and Dead
Shrubs: plants (non-trees), woody stems
Herbs: non-woody herbaceous plants including ferns, moss, lichens, sedges, and grasses (< 6 ft in height)
Live: Still attached
Dead: Still attached or dislodged, but not down and decaying
Slash/Residue Piles
Every slash pile, whose center coincides with a subplot, is assigned to a shape category, dimensions measured,
and density estimated
Subplot CCPile AZ
Shape LNG1 LNG2 WID1 WID2 HT1 HT2Pile Den.
1 1 28 1 10 12 4 3 4 2 20
Slash/Residue Tally Rules
• Tally CWD piles where efficiency of sampling is improved using pile protocol instead of transects
• Pile’s center must be in accessible forest land
• Pile’s center must be < 24 ft h.d. from subplot center
• Pile must contain pieces of CWD >= 3” diameter
• Estimate % of pile that contains CWD >= 3” (packing ratio)
Pile Shape Codes
Pile Density Estimation
=Stacked cord approaches 80% density
= =01% 20%
End of Part 2 of 3
http://www.ncrs.fs.fed.us/4801/national-programs/indicators/dwm/
Improving DWM Data Quality3rd of 3 Part Training Series
Christopher Woodall
DWM National Indicator Advisor
Outline
• QA/QC Analysis
• What Customers Want
• Measurement Errors Hot and Cold Checks
• Top Ten List of Errors
• Training
QA/QC Analysis
The analysis of 2001-2004 DWM QA plots is currently ongoing. Matching algorithms are being developed for numerous measurement variables. Expect results for the 2006 P3 Training Sessions.
For more information contact: Chris Woodall @ NCFIA and Jim Westfall @ NEFIA
What Customers Want
Key
N
430°
150°
270°
30°
150°
270°
30°
150°
270°
30°
150°
270°
3
2
1
Transect Information
FWD < 0.25”& 0.26”-0.99”
FWD 1.00”-2.99”
CWD => 3.00”
6 ft. s.d.
10 ft. s.d.
24 ft. h.d.
s.d.= slope dist., h.d.=horizontal dist.
Sub-plot
Micro-plot
CWD Transect
FWD Transect
Distances between sub-plot points: 120 ft., Distance from sub-plot center and microplot center: 12 ft., Distance betweenSub-plot 1 and sub-plots 2, 3, and 4: 207.8 ft. at angles (degrees) 150, 210, and 270 respectively.
A uniform DWM sample design applied across
the entire United States producing per acre estimates of fuels, carbon, and wildlife
habitat
Measurement Errors
• Establishing Transects
• FWD Counts
• Slope versus Horizontal Distances
• CWD Diameters
• Correct Units for Duff, Litter, and Fuelbed Depths
• Microplot coverage and heights
Hot checks
Measurement Errors
• Number 1 priority is matching data and determining adherence to MQO’s
• Number 2 priority is determining cause for errors…then correcting cause
Cold/Blind Checks
Measurement Error Propagation
CWDDuff/Litter
FWD
Slash
Shrub/Herb
Transect
Database Processing Algorithms
Core TableMeasurement errors have varying magnitudes of effect
Measurement Error Simulation
Effect of 5, 10, 15% variation in down woody material measurement variables on total per acre tonnage estimates
0
1
2
3
4
5
6
7
8
5 10 15
Simulated Variation (%)
Va
ria
tio
n in
To
tal T
on
na
ge
Es
tim
ate
s
(%)FWD - 1-hr Count
Litter - Depth
CWD - Tran. Length
FWD - Tran. Length
Slash - Height1
Slash - Density
CWD - Diameter
Duff - Depth
Simulation Conclusions
Measurement variables whose errors least affect core table outputs: CWD decay, classes/transect lengths, litter depth, and FWD counts
Measurement variables whose errors most affect core table outputs: duff depths, CWD diameters, and slash pile densities
FIA’s Top Six LeastWanted DWM Errors
1. CWD Diameters2. CWD Lengths3. Duff Depths4. Litter Depths5. Slash Pile Density6. Missing Data
CWD Diameters
Crews mistakenly record CWD diameters to tenth of inch…used to P2 plots
Only measure to nearest inch!!
≠
CWD Lengths
Some log dimensions recorded in field are impossible
3 inches
15 feet
120 inches
=
Duff Depth
Duff is the heaviest down woody material per unit volume
Make sure your measurements (and units) are correct
Litter Depth
Much lighter than duff…however is usually much deeper
Don’t mistakenly enter the litter depth for duff depth
Slash Pile Density
Only neatly stacked wood can exceed 40-60% density!
Missing/Mismatched Data
AKA: Excruciating Headaches for Analysts
Missing/Mismatched Data
Example: DWM plot sheet indicates CWD transects on a condition class 2…however, only one condition class recorded in P2 record
Example: CWD piece is decay class 2, but is missing small and large end diameters
Might be your fault, might be data management’s fault, might be computer’s fault…no matter…do what you can to minimize mismatch errors
Training
Problem Areas
Problem: Field crews disturb the CWD too much trying to determine decay class or if segmented
Correction: Although field crews must disturb CWD pieces in order to acquire measurements, try to keep disturbance to a minimum
Problem Areas Cont’d
Problem: Field crews mistakenly enter extra digit for CWD diameter (40 instead of 4 inches)
Correction: Unless PDR’s catch them, be sure of very large CWD diameters
Problem Areas Cont’d
If CWD piece ends in water, treat as if underground,
measure piece to water edge
For FWD, if transect under water try to enter null values and
indicate in plot notes
Problem Areas Cont’d
Problem: Crews dig through litter hunting down pieces of FWDCorrection: Crews should only tally obvious FWD pieces, namely those on litter surface
Problem: Crews aren’t tallying FWD pieces hung up in slash/saplings Correction: Crews should tally all FWD pieces from forest floor up to 6 feet above ground
Problem Areas Cont’d
Problem: Crews either include too much of the litter layer or upper soil mineral horizons in estimation of duff depth
Correction: Crews should be absolutely sure of what is duff, litter, and mineral horizons. Be absolutely sure of duff measurements!!
Problem Areas Cont’d
Duff Depths:
1) Identify duff from mineral soil
2) Don’t include moss or litter material
3) What to do with deep duff4) Anything over 1 foot be
absolutely sure
Problem Areas Cont’d
Problem: Crews can’t decide on the fuelbed height measurement
Correction: Crews should only take 15-seconds to determine height of dead, down woody material, don’t over analyze, use local knowledge and reasonable definition of fuel ladders
Problem Areas Cont’d
1) Measure from top of duff to top of fuel complex
2) Fuel complex composed of dead FWD, CWD, shrubs, and litter
3) Gaps allowed in fuel complex where one would reasonably expect flame lengths to connect
4) Plum-bob not required, ocular estimate around sample point
5) 15-second rule…Don’t over analyze height of fuelbed…Use your experience and logicFuelbed Depths
Problem Areas Cont’d
Problem: Condition class boundary runs through microplot
Correction: Use entire forested condition of microplot to estimate coverage and heights
=100% cover of litter for forested conditions (don’t include asphalt or other non forested conditions in cover assessment)
Problem Areas Cont’d
1) Train with idea of imaginary 6.8 foot radius cylinder
2) Make sure crews know what herbs and shrubs include
3) Gaps allowed in fuel complex as long as reasonable
4) Branches from shrubs rooted outside microplot allowed
5) Train about vines and canopy herbaceous plants
Microplot Heights
Problem Areas Cont’d
Only include epiphytes or hanging moss up to
6 feet in height
Include vines that are within microplot
Problem Areas Cont’d
Only estimate density of CWD within pileDensity should rarely exceed 40%
70% 20% 01%
Slash Pile Densities
Battlefield Quotes
‘If it ain't broke, don't fix it' is the slogan of the complacent, the arrogant or the scared. It's an excuse for inaction, a call to non-arms.
Battlefield Quotes
"The commander in the field is always right and the rear echelon is wrong, unless proved otherwise."
Sample Design Changes
The DWM Indicator must be responsive to customer needs and improving science/techniques…
Don’t assume your ideas are insignificant, you collect the data, assume you know best and pass ideas upwards…
Submit your suggestions [email protected]
End of Part 3 of 3
http://www.ncrs.fs.fed.us/4801/national-programs/indicators/dwm/