11.0RM DOwN wOODY MATERIAL PILOT (DwM) · IMPORTANT. Please take notes in your field notebook as situations arise (either positive or negative). If you do not write it down when it

Interior West Survey Field Procedures, Version 3.01March, 2007

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11.0RM DOwNwOODYMATERIALPILOT(DwM)

11.0.1RM Down Woody Material (DWM) Pilot OverviewIn 2004 and 2005, DWM Pilot studies were conducted on National Forest System (NFS) lands on Phase 2 (P2) plots in Montana. The transect design implemented in 2004 included a subset of the national Phase 3 (P3) Coarse Woody Debris (CWD) transects, in addition to three 120-foot “traverse” transects between subplots 1 and 2, subplots 1 and 3, and subplots 1 and 4. The purposes of the pilots were threefold: first to maximize total transect length, second to separate fuel-loading estimates by type of transect (P3 vs. traverse) for statistical analysis, and third to identify the most efficient transect design that would meet our needs for P2 National Forest level fuel-loading estimates.

Preliminary analysis of the 2004 data showed that the P3 CWD transects were more time-consuming and had much higher variability in fuel-loading estimates than the “traverse” transects. Efficiency was also gained because “traverse” transects share the same horizontal line used to chain between subplots. As a result, in 2005 we decided to use only the “traverse” transect design for sampling all DWM components.

Another major time-saving change was the elimination of measuring end-point diameters and lengths of CWD pieces. Even though individual measurement of endpoint diameters and lengths of CWD pieces help improve volume estimates and subsequent fuel loadings, it’s expected that longer “traverse” transects will help recover this loss by reducing variability in estimates.

Elimination of the large-end diameters of CWD also compromises information on structural diversity, which is important for assessing wildlife habitat. In 2005, in order to better address wildlife structure related to large-end diameter, Region 1 NFS provided five broad structure-related diameter classes, which field crews assigned to individual CWD pieces. Generally, it is much quicker to assign a class than to measure each piece directly.

Future P2 DWM analysis will combine data from both 2004 and 2005 pilots for better estimates of variability in fuel loading and structure information at the National Forest level, and possibly identify further refinements in P2 DWM protocols in 2006. The results of this analysis, along with field crew feedback and time/logistics considerations will ultimately determine what final DWM methods are used on P2 plots in future inventories. Therefore, YOUR FEEDBACK IS VERY

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IMPORTANT. Please take notes in your field notebook as situations arise (either positive or negative). If you do not write it down when it occurs, there is a good chance that you will not remember the situation or the details when your input is requested.

The methods presented here are highly dependent upon use of P3 DWM field procedures. The 2006 P2 DWM inventory will use many of the established P3 methods under the “traverse” CWD transect design.

11.0.2RM IntroductionDown woody materials are an important component of forest ecosystems across the country. DWM is dead material on the ground in various stages of decay. Wildlife biologists, ecologists, mycologists, foresters, and fuels specialists are some of the people interested in DWM because it helps describe the:• Quality and status of wildlife habitats.• Structural diversity within a forest.• Fuel loading and fire behavior.• Carbon sequestration – the amount of carbon tied up in dead

wood.• Storage and cycling of nutrients and water – important for site

productivity.

DWM is only sampled in accessible forest conditions intersected by the transect. If a transect crosses a nonforest condition, the boundaries of the condition are recorded (see section 11.2) but no DWM or fuels measurements are taken along this portion of the transect. The majority of DWM in the inventory is sampled using the line intersect sampling method (also called planar intercept method). In this method, transects are established, and individual pieces of CWD or Fine Woody Debris (FWD) are tallied if the central axis of the piece is intersected by the plane of the transect. In addition, each piece must meet specified dimensions and other criteria before being selected for tally. Special procedures apply when a CWD piece lays across a condition class boundary (section 11.1).

11.0.3RM Definition of Down Woody MaterialsCWD – In this inventory, CWD includes downed, dead tree and shrub boles, large limbs, and other woody pieces that are severed from their original source of growth. CWD also includes dead timber and single-stemmed woodland trees (either self-supported by roots, severed from roots, or uprooted) that are leaning > 45 degrees from vertical. Also included are non-machine processed round wood such as fence posts and cabin logs. For standing multi-stemmed woodland trees such as



juniper, only tally stems that are dead, detached, and on the ground. For all dead multi-stemmed woodland trees that do not qualify as standing dead woodland trees (Section 0.4.3) tally all stems attached or detached that meet the size requirements for CWD pieces.

CwDdoesnotinclude:1. Woody pieces < 3.0 inches in diameter at the point of intersection

with the transect.2. Woody pieces < 3.0 feet in length.3. Dead trees leaning 0 to 45 degrees from vertical.4. Dead shrubs, self-supported by their roots.5. Trees showing any sign of life.6. Stumps that are rooted in the ground (i.e., not uprooted).7. Dead foliage, bark or other non-woody pieces that are not an

integral part of a bole or limb. (Bark attached to a portion of a piece is an integral part).

8. Roots or main bole below the root collar.

FWD – In this inventory, FWD includes downed, dead branches, twigs, and small tree or shrub boles that are not attached to a living or standing dead source. FWD can be connected to a larger branch, as long as this branch is on the ground and not connected to a standing dead or live tree. Only the woody branches, twigs, and fragments that intersect the transect are counted. FWD can be connected to a down, dead tree bole or down, dead shrub. FWD can be twigs from shrubs and vines. FWD must be no higher than 6 feet above the ground to be counted.

FwDdoesnotinclude:1. Woody pieces > 3.0 inches in diameter at the point of intersection

with the transect.2. Dead branches connected to a live tree or shrub; or to a standing

dead tree or dead shrub.3. Dead foliage (i.e., pine or fir needles, or leaf petioles).4. Bark fragments or other non-woody pieces that are not an integral

part of a branch, twig, or small bole.5. Small pieces of decomposed wood (i.e., chunks of cubical rot)

11.0.4RM Use of hardcopy data sheets

Every plot needs to have the time study completed on the hardcopy form and included in the field packet before submission. This information is not included on the PDR. All other field data for the DWM P2 pilot will be collected on the PDR; however, hardcopy forms

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can be used as a backup. If a transect has no DWM you must still complete the first line of that portion of the data sheet with dashes to show there is no DWM. If there is data for a line and the same line has a box with “Y – N” you must circle either “Y” or “N”. You may not leave the “Y – N” option blank.

11.0.5RM Recording “Time to complete” box on Form 1

The time study portion of this pilot is very important. Youmustcompletely fill out the “Time to complete” section in the upper righthandportionofForm1oneachplottothenearest15minutes. An example of recording “Total” time would be: if two crew people spend a total of 45 minutes on the DWM study then enter 1.50 for Total hours, since we want total crew-person hours. Also record onlythe total time spent on making the calls on the large-end diameter classes. This will give an idea how long it takes to assess this variable. If less than 7.5 minutes record zero.

11.1RM TraverseTransectSampling

11.1.1RM Locating and Establishing Line TransectsTraverse transects are established between each of subplots 1 and 2, subplots 1 and 3, and subplots 1 and 4, if accessible forest land is sampled on any of the 24.0-foot radius subplots (CONDITION CLASS STATUS = 1). If so, 360 feet of traverse transect length needs to be accounted for by condition, horizontal distance , and sampled horizontal distance (Figure 55).



P2 DWM Transect Layout

4 3

2

1

120’ CWD Transects 10” FWD Transects Duff/Litter Depth Measurement Point

Figure 55. Traverse transect plot layout

11.1.2RM CWD transectsTransects begin at the subplot 1 perimeter (24.0 horizontal feet) and extend 120 horizontal feet through the subplot centers to the farther edge of subplots 2, 3, and 4 at 360, 120, and 240 degrees azimuth, respectively (Figure 55).

11.2RM Transect Line SegmentingAny traverse transect that meets the criteria for establishment (See section 11.1) will be segmented by condition class. Transect lines are segmented to determine the length of transect that occurs within each condition class intersecting the line. A segment is a length of transect that is in one condition.

Starting at the subplot 1 perimeter and working towards the other fixed radius plot boundary, each segment of transect line in a different condition class is delineated and recorded as a separate record (no more than two conditions per traverse will be segmented—see hierarchical rules below). The transect must extend a total of 120.0 feet horizontal distance. Each time a condition boundary is crossed the segment is recorded (Figure 56)

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P2 DWM Transect Layout

Traverse transect length: On subplots – 144’ Off subplots – 216’ 72’ on each traverse Total – 360’

Traverse CWD transects

P3 FWD transects

Litter, duff depth

Condition 3 Condition 1 Condition 2

4 3

2

1

120° traverse 120 feet



65’

45’

10’

50’

45’

10’’

15’

CWD piece

Figure 56. Transect Layout with 3 different conditions.

Application of traverse condition rules for segmentation:

Condition Hdistance SampledHdistanceSubplot 2 1 120 120

Subplot 3 1 10 10 2 50 50 1 45 45 2 15 15

Subplot 4 1 45 45 3 65 65 1 10 10



For remeasurement plots: If the location of subplots 2, 3, and 4 are not obvious from subplot 1(e.g. dense brush, other obstacles blocking view, etc.) it may be easier to start at subplots 2,3, and 4 and work in reverse direction for tallying DWM components. This will help avoid missing the subplot 2, 3, and 4 stakes, which could cause a break in CWD transects. It could also cause inaccurate sample locations for FWD or duff/litter, which are tied to subplots 2, 3, and 4 stakes.Note: Regardless of the order of CWD tally, use the same condition numbers assigned on the subplot.

Do not sample DWM on transect segments in conditions that are not accessible forest land (e.g. nonforest , noncensus water, hazardous, etc.). However, all 360.0 horizontal feet of transect length are accounted for by condition, horizontal distance, and sampled horizontal distance regardless of condition status.

Since conditions aren’t necessarily mapped or identified between subplots and only two conditions will be segmented per traverse the following hierarchical rules will be used to make traverse transect segmenting more simple and consistent with the core condition and subplot information:

1. Only those conditions identified on the subplots and also recorded on the condition description will be considered legitimate for traverse transect segments. Any other conditions encountered on the traverses between subplots will be ignored. In other words, no new conditions will be considered due to traverse transect sampling.

2. If in doubt about whether a condition should be segmented, do not segment.

3. No more than two conditions per traverse will be considered and segmented. Use hierarchical priority rules (see next two rules) to choose among conditions when more than two conditions are encountered on a traverse. This should rarely occur.

4. Condition boundaries that occur on the subplots have first priority for traverse transect segmenting.

5. Conditions that occur between subplots will have the next priority for traverse transect segmenting (see rule # 8 for exception).

6. Distinct condition boundaries between subplots will be identified

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and recorded to the nearest horizontal foot by condition.

7. Indistinct condition boundaries (transition zones) between subplots will be split mid way between the subplots at 36 feet. The first condition will be assigned the first 36 feet and the second the next 84 feet.

8. Ignore linear features that are exceptions to the size and width requirements that occur between the subplots (less than 1.0 acre in size and 120 feet wide) like improved roads, maintained rights-of-way, etc. that cross the traverse transects, and assign conditions as though they weren’t there.

Note: Do not include portions of transects that cross linear features for total SAMPLED HORIZONTAL DISTANCE (see 11.2.3)

By no means will these rules cover all possible scenarios. Use them with the idea in mind that for most plots a procedure for assigning conditions to traverse transect pieces has been documented and followed to capture most of the condition variability. Please make notes of any different situations encountered.

11.2.1RM CONDITION CLASS NUMBERRecord the code indicating the number of the condition class for the transect segment. Use the same code assigned to the condition class on the subplot or elsewhere on the plot. When collected: All tally segmentsField width: 1 digitTolerance: No errorsMQO: At least 99% of the timeValues: 1 to 9

11.2.2RM HORIZONTAL DISTANCEStarting at the subplot 1 perimeter record the traverse transect length in horizontal feet (nearest foot) segmented by condition class. See section 11.2for specifics on condition segmenting rules.

When collected: All tally segmentsField width: 3 digitsTolerance: +/- 1.0 ftMQO: At least 95% of the timeValues: 001 to 120



11.2.3RM SAMPLED HORIZONTAL DISTANCERecord the SAMPLED HORIZONTAL DISTANCE (nearest foot) for each segment. Most of the time this is a repetition of the horizontal distance. However, for conditions other than accessible forest land (see section 11.2 for specifics) the SAMPLED HORIZONTAL DISTANCE is recorded as zero. Also, transect segments or portions of segments within accessible forest land conditions that cannot be accuratelysampleddue to snow/water or that cross nonforest linear features (see not in 11.2 item 8) are not included in SAMPLED HORIZONTAL DISTANCE.

When collected: All tally segmentsField width: 3 digitsTolerance: +/- 1.0 ftMQO: At least 95% of the timeValues: 000 to 120

11.3RM Sampling Methods for Coarse Woody Debris (CWD)

11.3.1RM Tally Rules for Coarse Woody Debris (CWD)1. Coarse woody debris (CWD) is sampled in accessible forest land

conditions only. Tally a piece if its central longitudinal axis intersects the transect,

and the condition class is accessible forest land at the point of intersection (Figure 57). The entire piece is assigned to this condition

Condition class 1 (accessible forest land)

Central longitudinal

axis

Transect line

Point of intersection

Figure 57. Tally rules for CWD.

2. Tally dead trees, shrubs, and tall stumps that are leaning > 45 degrees from vertical. Do not tally live trees or shrubs. Do not

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tally standing dead trees and tall stumps (≥ 3.0 feet in length) that are still upright and leaning < 45 degrees from vertical. Follow the same rules for down trees as outlined in section 5.0 ‘Tree and Sapling Data. Most CWD will be laying on the ground.

3. Tally the portions of standing dead shrubs that intersect the transect line. The pieces must still meet the minimum length and diameter requirements.

4. The minimum length of any tally piece is 3.0 feet. When CWD pieces are close to 3 feet, measure the length to the nearest 0.1 foot to determine if it is >3.0 feet.

5. Decay class of the piece determines which variables to collect (see section 11.3.3).

Fordecayclasses1to4: tally a piece if it is > 3.0 inches in diameter at the point of intersection with the transect. The piece must be > 3.0 feet in length and > 3.0 inches or more in diameter along that length. If the intersect diameter is close to 3.0 inches, measure the diameter to the nearest 0.1 inch to determine if the piece qualifies (Figure 58).

Note: The 3.0 inch requirement along the 3.0 foot minimum length is derived from P3 protocol which states “the piece ends where it becomes smaller than 3.0 inches”.

Figure 58. CWD tally rules for decay classes 1-4.



Fordecayclass5: tally a piece if it is > 5.0 inches in diameter at the point of intersection and > 5.0 inches high from the ground at the point of intersection. The piece must be > 3.0 feet in length and > 5.0 inches in diameter along that length. The reason for treating decay class 5 pieces differently is because they are difficult to identify, especially when heavily decomposed. Only pieces that still have some shape and log form are tallied—humps of decomposed wood that are becoming part of the duff layer are not tallied.

6. Tally pieces created by natural causes (examples: natural breakage or uprooting) or by human activities such as cutting. Estimate the required data for pieces that are part of machine-piled slash piles or windrows, or that are part of a log “jumble” at the bottom of a steep-sided ravine.

7. Tally a piece only if the point of intersection occurs above the ground. If one end of a piece is buried in the litter, duff mineral soil, or water the piece ends at the point where it is no longer visible. Clarification: In order to be tallied the piece needs to have three consecutive feet of exposed visible length above ground at the point of intersection. Do not consider things like small shrubs, grasses or forbs that may lay across a piece as below ground, but do consider litter, duff, mineral soil, or water on top of the piece as below ground.

8. If the central longitudinal axis of a piece is intersected more than once on a transect line or if it is intersected by two transect lines, tally the piece each time it is intersected (Figure 59).

Figure 59. Tally a CWD piece each time it crosses the transect

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9. If a piece is fractured across its diameter or length, and would pull apart at the fracture if pulled from either end or sides, treat it as two separate pieces. If judged that it would not pull apart, tally as one piece. Tally only the piece intersected by the transect line.

10. Do not tally a piece if it intersects the transect on the root side of the root collar. Do not tally roots.

11. When the transect crosses a forked down tree bole or large branch connected to a down tree, tally each qualifying piece separately. To be tallied, each individual piece must meet the minimum diameter and length requirements.

12. In the case of forked trees, consider the “main bole” to be the piece with the largest diameter at the fork. Variables for this fork such as DECAY CLASS should pertain to the entire main bole. For smaller forks or branches connected to a main bole (even if the main bole is not a tally piece), variables pertain only to that portion of the piece up to the point where it attaches to the main bole (Figure 60).



Figure 60. CWD tally rules for forked trees.

13. If a transect intersects a nonforest condition, no CWD is tallied in the nonforest condition.

11.3.2RM Recording Procedures for CWDThe tolerance for the total number of pieces (> 3.0 inches, transect diameter) tallied across all transects on the plot is : +/- 2 piece or +/- 5%, whichever is greater for the plot. Note: always round up to a whole piece count when using the 5% option.

11.3.3RM DECAY CLASSRecord a 1-digit code indicating the decay class of the piece. Code the decay class which predominates along the observed total length of the piece. Use the guide in Section 5.23 to determine the DECAY CLASS.

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When Collected: All tally piecesField width: 1 digitTolerance: +/- 1 classMQO: At least 90% of the timeValues: 1-5 (described in Section 5.23)

Note: DECAY CLASS 5 pieces can be difficult to identify because they often blend into the duff and litter layers. They must still resemble a log, therefore, the first tally rule is that they must be > 5.0 inches in diameter, > 5.0 inches from the surface of the ground, and at least 3.0 feet long. Decomposed logs that are slightly elevated ‘humps’ on the ground are not tallied.

DECAY CLASS: The table in Section 5.23 was developed primarily for Douglas-fir in the Pacific Northwest. At the present time, there are no other tables available to use to describe decay classes for other species or locations. Concentrate on the structural integrity and texture when estimating a decay class for CWD logs.

If a log is case hardened (hard, intact outer sapwood shell) but the heartwood is rotten, code this log as a DECAY CLASS 2 with a IS THE PIECE HOLLOW? code of 1. DECAY CLASS 1 should be reserved for ‘freshly fallen’ logs that are completely intact (i.e., recent windfalls, or harvest).

11.3.4RM SPECIESRecord the code indicating the species of the piece. Since CWD pieces are not necessarily always tally species, record the most detailed available species codes. Some species codes are only genus specific (e.g. Prunus), or hardwood-softwood specific. Search for the species code that has the most detail for the identified piece. Enter a code of ‘0001’ for SPECIES if the tally piece is a shrub or vine. However, if a specific code exists (e.g. pin cherry) then use it instead of the generic shrub code.

Species identification may be uncertain for some pieces. The piece’s bark (either attached or sloughed and laying beside the piece), branching pattern (if the branches are still present), or heartwood smell (particularly if cedars, Douglas-fir, or western hemlock) may provide clues. On remeasurement plots, see what tree species were tallied in past inventories. One way to distinguish hardwoods from softwoods is by the type of decay present. Hardwoods usually have a white or grayish stringy rot, while softwoods usually have a reddish-brown blocky rot. If it is not possible to identify the species, attempt to



estimate if it is softwood or hardwood. Enter code 0299 for unknown conifer or 0998 for unknown hardwood. If all else fails, enter the unknown SPECIES code (0999).

When Collected: DECAY CLASS = 1 to 4 Field width: 4 digitsTolerance: No errorsMQO: At least 80% of the timeValues: See species codes in Appendix 3.

11.3.5RM DIAMETER AT POINT OF INTERSECTION (transect diameter)Record the code indicating the piece’s diameter at the point where the transect intersects the longitudinal center of the piece. If the diameter is close to 3 inches, measure the diameter to the nearest 0.1 inch to determine if the piece is actually >3.0 inches and a valid tally piece. Mark the location of the transect diameter for decay classes 1-4 with a crayon to aid in remeasurement by QA crews. Do not mark pieces in reserved areas. The diameter is recorded to the nearest inch.

When Collected: All tally piecesField width: 3 digitsTolerance: Pieces < 20.0 in diameter: +/- 3 inPieces > 20.0 in diameter: +/- 20%MQO: At least 90% of the timeValues: 003 to 200

11.3.6RM LARGE END DIAMETER CLASSEstimate the appropriate class code for the large end diameter for each CWD piece. If the large end diameter is close to a class breaking point it may be necessary to directly measure the diameter.

The large end will occur either at a broken or sawn end, at a fracture, or at the root collar. If the end is splintered or decomposing (sloughing off), measure the diameter at the point where it best represents the overall log volume.

The diameter is most commonly measured by holding a tape above the log, at a position perpendicular to the length. It is useful to carry a steel carpenters retracting tape to measure diameters. Other methods include wrapping a tape around the bole if possible, holding a straight-edge ruler above the piece, or using calipers.

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For pieces that are not round in cross-section because of missing chunks of wood or “settling” due to decay, measure the diameter in two directions and take an average. Estimate the longest and shortest axis of the cross-section (“A” and “B” in Figure 61), and enter the average in the diameter field. This technique applies to intersect large-end diameters.

Figure 61. Estimating the diameter of pieces that are not round in cross-section.

If the transect intersects the log at the decayed or splintered end (Figure 62) (i.e., the portion where we do not consider it part of the log because it is falling apart), record the diameter at this location as the intersect diameter, but record the large end diameter class according to our established rules (i.e., at the points where they best represent the log volume). If you have a major split located just at the end, treat it as one log and take a diameter around the end (take two measurements if it is odd shaped). Length would be measured between the large and small end diameters. Piece length ends when log diameter becomes <3.0 inches in diameter.

Figure 62. Example of decayed end intersection the transect.



When Collected: DECAY CLASS = 1 to 4Field width: 1 digitTolerance: No errorsMQO: At least 90% of the timeValues: 1 to 5

Code Diameter Class1 3.0” to 4.9”2 5.0” to 8.9”3 9.0” to 14.9”4 15.0” to 20.9”5 21.0”+

11.3.7RM CONDITION CLASS NUMBERRecord the code indicating the number of the condition class that contains each CWD piece. Use the piece’s central axis at the transect point of intersection to assign each piece to the appropriate condition. If there is only one condition on the traverse assign all pieces to that condition. If a piece is borderline between two conditions, assign it to the first condition on the traverse. See Section 11.2 for rules for assigning conditions.

Field width: 1 digitTolerance: correctMQO: At least 90% of the timeValues: 1 - 9

11.3.8RM IS THE PIECE HOLLOW?Record the code indicating whether or not the piece is hollow (Figure 63). A piece is considered hollow if a cavity extends at least 2 feet along the central longitudinal axis of the piece, and the diameter of the entrance to the cavity is at least 1/4 of the diameter of the piece where the entrance occurs. The entrance occurs at the point where the circumference of the cavity is whole -- the point where wood is present completely around the circumference of the cavity. The length of the cavity begins at this point.

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Figure 63. Determining if the piece is hollow.

When Collected: DECAY CLASS = 1 to 4Field width: 1 digitTolerance: No errorsMQO: At least 90% of the timeValues: Y or N

Code Y Meets the criteria for a hollow log.N Does not meet criteria for being a hollow log

11.3.9RM IS THE PIECE ON A SUBPLOT?Record the code indicating whether or not the piece is on the subplot. Use the pieces central axis at transect point of intersection to determine if the piece falls within the 24.0 horizontal perimeter of the farther subplot. If a piece falls exactly on the subplot 1 perimeter, record “N” for piece not on a subplot. If a piece falls exactly on subplot 2, 3, or 4 perimeter, record “Y” for piece is on a subplot.

Values: N or YField width: 1 digitTolerance: correctMQO: At least 90% of the time



11.4RM SAMPLING RESIDUE PILESIn some circumstances, piles or windrows created directly by human activity and log piles at the bottom of steep-sided ravines will be encountered on a transect. If this is encountered, estimate the number, diameter, and other required data of CWD pieces that intersect the traverse, and record as separate pieces as best as possible.

11.5RM Sampling Methods for Fine Woody Debris (FWD)

1. Fine Woody Debris (FWD) is sampled when transect starting point occurs in accessible forest land conditions (CONDITION CLASS STATUS = 1). The length of FWD transects are measured in slope distance--no correction is applied to obtain a horizontal distance. The FWD transects start at 14.0 feet slope distance from the subplot stake and extends for 6.0 or 10.0 feet slope distance. Estimates of FWD biomass calculated in the office, will include a slope correction factor obtained from the FWD transect (See FWD TRANSECT PERCENT SLOPE).

2. Only sample FWD that intersects a plane from the ground to a height of 6 feet.

3. FWD is sampled in three size classes. Two of the FWD size classes (0.01 to 0.24 inches and 0.25 to 0.9 inches) are counted on a 6-foot transect, from 14 to 20 feet. Pieces in the third size class (1.0 to 2.9 inches) are counted on a 10-foot transect, from 14 to 24 feet (see section 11.1.1 for details on transects). These transects overlap. Note: individual diameters are not recorded for FWD.

4. Count a piece of FWD if it intersects the transect. Only count twigs, branchs, wood fragments, or shrub/tree boles which are woody. Do not count needles or non-woody parts of a tree or shrub.

5. Accumulate the number of pieces counted within each size class and enter the total count on one record for the subplot. If there is no tally on a transect, enter zeros for the count.

6. Accurate counts of FWD can be conducted efficiently up to about 50 pieces for small and medium size classes, and up to 20 pieces for the large size class. After that, crews can begin estimating

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counts in a systematic fashion. Transects that fall on very dense FWD where counting is nearly impossible, can be subsampled and calculated. For example, an accurate count can be conducted on a 2.0-foot section of the transect and then multiplied by 3 to provide an estimate for the 6 foot transect, as long as the crew feels that the remaining transect has a similar density of FWD pieces.

7. If a transect intersects a large pile of material such as a wood rat’s nest or a recently fallen tree (with many attached fine branches), crews should estimate a count based on #6 above, but also enter a code indicating that this is an unusual situation (see section 11.5.9).

8. If rocks, logs, or other obstructions are present along the transect (14- to 24-foot section) include any FWD that is present on top of these obstructions in the respective FWD counts. If the obstructions are so large (huge boulder) that the top surface cannot be seen, assume the count is zero in this area, and continue counting if there is transect line beyond the boulder.

9. If any portion of the FWD transect is covered by snow or water, do not sample FWD. Either the whole transect is sampled or none.

11.5.1RM FWD transectsFWD transects that originate in accessible forest land conditions are sampled. Either the whole transect is sampled or none. See instructions for FWD sampled (Section 11.5).

Establish FWD transects at the end of subplots 2, 3, and 4 traverse transects (360, 120, and 240 degrees azimuth. Figure 55). FWD is tallied within 3 size classes. Because FWD is generally present in higher densities, a shorter transect will pick up an acceptable amount of tally. The transect begins at 14 feet (slope distance) from subplots centers’ 2, 3, and 4 and extends out either 6 or 10 feet (slope distance) depending on the FWD size class, as follows:

Category of FWD

Size Class

Diameter range Transect length (slope distance)

Transect location (slope distance)

Small FWD 1 .01 in to 0.24 in 6 feet 14 to 20 feetMedium FWD 2 0.25 in to 0.9 in 6 feet 14 to 20 feetLarge FWD 3 1.0 in to 2.9 in 10 feet 14 to 24 feet



Note that the FWD transects are slope distance not horizontal distance. The formulas used to estimate biomass from the data contain an adjustment for slope. It is helpful to have a size gauge available until your eye is ‘trained’ to recognize the 3 size classes. Examples include a plastic or cardboard card with 3 notches cut for each size class, or a set of 3 dowels representing each size class.

11.5.2RM FWD SAMPLEDIf the FWD transect originates in a nonforest condition or if snow/water covers any portion of the FWD transect then do not sample any FWD.

When collected: Each traverse transectField width: 1 digitTolerance: No errorsMQO: At least 99% of the timeValues: 1 to 2

Code1 All FWD sampled2 No FWD sampled

11.5.3RM FWD TRANSECT PERCENT SLOPERecord the percent slope to the nearest 5% for the FWD transect, from sampling starting point (14 feet slope distance from subplot center) to the ending point (24 feet slope distance from subplot center).

When Collected: When FWD SAMPLED = 1Field width: 3 digitsTolerance: No errorsMQO: At least 90% of the timeValues: 5% increments from 0 to 120

11.5.4RM CONDITION CLASS NUMBERFWD is assigned to only one condition class per transect.Record the code indicating the number of the condition class where FWD sampling begins (14 feet slope distance from the subplot centers).

When collected: All tally segmentsField width: 1 digitTolerance: No errorsMQO: At least 99% of the timeValues: 1 to 9

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11.5.5RM SMALL FWD COUNTRecord the number of pieces counted in this size class (0.01 to 0.24-inch diameter) along the transect segment. An accurate count should be conducted up to 50 pieces. If the count exceeds 50, the transect can be subsampled to estimate a total count for the transect segment (see 11.5, #6)

When collected: When FWD SAMPLED = 1Field width: 3 digitsTolerance:0 to 50 = +/- 20% of the total count for the transect51 to 100 = +/- 25% of the total count for the transect100 + = +/- 50% of the total count for the transectMQO: At least 90% of the timeValues: 000 to 999

11.5.6RM MEDIUM FWD COUNTRecord the number of pieces counted in this size class (0.25 to 0.9-inch diameter) along the transect segment. An accurate count should be conducted up to 50 pieces. If the count exceeds 50, the transect can be subsampled to estimate a total count for the transect segment (see11.5, #6)

When collected: When FWD SAMPLED = 1Field width: 3 digitsTolerance: +/- 20% of the total count for the transect MQO: At least 90% of the timeValues: 000 to 999

11.5.7RM LARGE FWD COUNTRecord the number of pieces counted in this size class (1.0 to 2.9 inch diameter) along the transect segment. An accurate count should be conducted up to 20 pieces. If the count exceeds 20, the transect can be subsampled to estimate a total count for the transect segment (see section 11.5, #6).

When collected: When FWD SAMPLED = 1Field width: 3 digitsTolerance: +/- 20% of the total count for the transectMQO: At least 90% of the timeValues: 000 to 500



11.5.8RM HIGH COUNT REASONEnter a code if any of the counts on a transect are greater than 100 pieces.

When Collected: When the count on the transect >100Field width: 1 digitTolerance: No errorsMQO: At least 90% of the timeValues: 0 - 4

Code0 FWD is not unusually high1 High count is due to an overall high density of FWD across the

transect2 Wood Rat’s nest located on transect3 Tree or shrub laying across transect 4 Other reason

11.6RM DUFF and LITTER DEPTH MEASUREMENTSDepth measurements are sampled only in accessible forest land conditions (Condition class status =1). The depth of the duff layer and litter layer are important components of fire models used to estimate fire behavior, fire spread, fire effects, and smoke production. An average depth will be calculated in the office and stored with other information about the condition class on the plot. If a log, rock, or other obstruction intersects the measurement location, do not measure the duff or litter depth.

11.6.1RM Definitions

1. Litter is the layer of freshly fallen leaves, needles, twigs (< 0.25 inch in diameter), cones, detached bark chunks, dead moss, dead lichens, detached small chunks of rotted wood, dead herbaceous stems, and flower parts (detached and not upright). Litter is the loose plant material found on the top surface of the forest floor. Little decomposition has begun in this layer.

Litter is flash fuel – so think about it as the loose material that is exposed to the air, capable of igniting quickly and carrying a fire across the surface of the forest floor.

Litter does not include bark that is still attached to a down log, or rotten chunks of wood that are still inside a decaying log or log end (i.e., if a decayed log end has a lot of rotten cubes or pieces

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laying on a log surface and exposed to air, they are considered part of the log and not litter – fire would burn differently if it hit a pile of rotten punky wood chips, cradled by the unrotted sapwood shell). If these rotten chunks have spilled out to the ground and are actually on the ground surface, then they would be included in the litter layer.

Litter does not include animal manure.

2. Duff is the layer just below litter. It consists of decomposing leaves and other organic material. You should see no recognizable plant parts, the duff layer is usually dark decomposed organic matter. When moss is present, the top of the duff layer is just below the green portion of the moss. The bottom of this layer is the point where mineral soil (A horizon) begins.

Crews should be absolutely sure they are measuring deep duff depths, instead of mineral soil layers or parts of the litter layer. Duff can easily weigh more than 6 times that of litter. If unsure of the bottom of the duff layer, crews should feel the texture of the suspect material in their hand. Rub the soil between your fingers. Does it crumble (duff) or feel more like modeling clay (mineral).

11.6.2RM Overview of Measurements

Depth measurements will be taken at the end of each 120-foot horizontal traverse transect that is within an accessible forest land condition. See P2 DWM TRANSECT LAYOUT for transect details.

The duff and litter variable has two options for indicating if duff and litter were measured at each sample location. A value of 1 is entered if duff and litter were sampled (no obstruction). A value of 2 is entered if no duff and litter are sampled (obstruction).

11.6.2.1RM How to sample Duff and Litter

Carefully expose a shallow profile of the forest floor by digging out an area at the sample point using a knife, hatchet, or other tool. Estimate the depth of each layer with a ruler to the nearest 0.1 inch.

As you dig the hole for this measurement, if you encounter a rock, root, or buried log – stop the depth measurement at this point.



The height of the litter should be measured at the top of the loose material located at the sample point on the transect. Try to preserve the conditions of this location by walking around this point, so the QA staff will measure the same height as the original crew.

11.6.3RM SAMPLEDRecord the code indicating if the depth of the duff and litter layer was measured.

When collected: For each traverse transectField width: 1 digitTolerance: No errorsMQO: At least 99% of the timeValues: 1 or 2

1 All sampled: Duff and litter2 Nothing sampled

11.6.4RM DUFF DEPTHRecord the code indicating the depth of the duff layer to the nearest 0.1 inch.

When collected: When SAMPLED = 1Field width: 3 digitsTolerance: +/- 0.5 inchMQO: At least 90% of the timeValues: 00.0 to 99.9

11.6.5RM LITTER DEPTHRecord the code indicating the depth of the litter layer to the nearest 0.1 inch.

When collected: When SAMPLED = 1Field width: 3 digitsTolerance: +/- 0.5 inchMQO: At least 90% of the timeValues: 00.0 to 99.9

11.7RM ACKNOWLEDGEMENTSContact information for the National Advisor for this indicator is: Chris Woodall, USDA Forest Service, North Central Research Station, 1992 Folwell Ave, St. Paul, MN 55108, [email protected], http:\\ncrs2.fs.fed.us\4801\DWM .

mailto:Chris

mailto:[email protected]

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11.8RM P2 DWM Traverse Data Sheets

Documents

11.0RM DOwN wOODY MATERIAL PILOT (DwM) · IMPORTANT. Please take notes in your field notebook as situations arise (either positive or negative). If you do not write it down when it