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 cwoodall@fs.fed.us

End of Part 3 of 3

http://www.ncrs.fs.fed.us/4801/national-programs/indicators/dwm/