Proposed FIA DWM protocol

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Proposed FIA DWM protocol

• July 2009

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Why a P2-DWM protocol?

• Increasing need for information about the DWM
  biomass and carbon pool
• Desire for national protocol, with less effort
  needed than for P3 DWM
• Desire for national consistency
• Desire rapid assessments (e.g. MS hurricane)
  option

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Why a new DWM protocol design effort?

• Desire for more details on what we gain/lose by
  using different variables or transect
  configurations
• Based on FIA information needs
• Design guided by empirical data
• Integrated with current P3 DWM protocol (MT
  Direction develop a P2 DWM protocol that is a
  subset of P3 DWM protocols and also address and
  correct whatever P3 DWM protocols problems are
  identified in the re-work process)

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FIA Information Needs

• Volume, biomass, carbon
• Fuel Loading Biomass per acre
• Wildlife/Ecological CWM length per acre
  number of logs by large-end diameter 

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Results of Analyses

• Estimates and variance minimally affected by
  transect configuration transect orientation,
  location, or multiple piece crossings.
• Length is the primary factor for reducing
  variance.
• Additional plots buys more than adding transects
  or transect lengths to fewer plots.
• Estimates are sensitive to log and FWM
  inclination, decay class biomass reduction
  factors, and other compilation assumptions.

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How does the proposed design integrate P2 and P3
DWM?

• Three Protocol Options
• Protocol Improvements

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PROTOCOL OPTIONS

• OPTION I. BASE (CORE-OPTIONAL PROTOCOL for P2
  Plots) Provides information about volume,
  biomass, carbon, and fuel load per acre,
  addressing the primary FIA information needs.

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PROTOCOL OPTIONS

• OPTION I. BASE (CORE-OPTIONAL PROTOCOL for P2
  Plots) Provides information about volume,
  biomass, carbon, and fuel load per acre,
  addressing the primary FIA information needs.
• OPTION II. WILDLIFE/ECOLOGICAL (CORE PROTOCOL for
  P3 Plots) Captures additional CWM structural
  information to address wildlife questions.

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PROTOCOL OPTIONS

• OPTION I. BASE (CORE-OPTIONAL PROTOCOL for P2
  Plots) Provides information about volume,
  biomass, carbon, and fuel load per acre,
  addressing the primary FIA information needs.
• OPTION II. WILDLIFE/ECOLOGICAL (CORE PROTOCOL for
  P3 Plots) Captures additional CWM structural
  information to address wildlife questions.
• OPTION III. RAPID ASSESSMENT (CUSTOMIZED
  PROTOCOL) Accommodates the need for a temporary
  response to significant events allows
  customization of the protocol for assessment
  information needs.

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Measured variables

• Base protocol (P2) addresses volume, biomass,
  carbon, and fuel load per acre with these
  variables CWM species, decay class, and
  intersect diameter FWM counts and litter/duff
  depth.
• Wildlife/Eco package (P3) to get CWM size class
  data, density(logs/ac), and cavity info large
  small end diameter, length, and hollow cavities.
• Any non-base CWM variable can be measured as an
  optional add-on (e.g. large-end diameter or
  length).
• Some non-base, dropped CWM variables are
  preserved and available for optional add-ons as
  desired e.g., CWM history, log charred by fire.

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Protocol Improvements

• Pile measurement simplified moved to transect
  cross-section instead of subplot 3-D volume
  estimate.
• Microplot fuels and fuelbed depth dropped from
  all options optional fuelbed ID from Scott
  Burgan (2005 RMRS-GTR-153) photo-series
  provided.
• Duff and litter depth non-sampled status
  clarified.
• Improved compilation parameters included.
• Further research needs highlighted.

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Proposed transect design

• Two 24 transects per subplot (transects start at
  subplot center). Transects connect to form a
  straight-line across subplot (reduces multiple
  intersections of same piece).
• New transect azimuths more balanced than choosing
  2 transects/subplot from the current P3 design.
• Transects may be extended onto macroplot if
  macroplot is mapped and extra length desired.
• A third 24 transect may be added if maintaining
  transect length is important (e.g. to finish a P3
  cycle using current design).

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Proposed DWM Protocol
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Strengths of the proposed transect design

• Minimizes orientation bias
• Reduces multiple intersections of the same piece
  by different transects
• Gain in field efficiency
• P2 / P3 integration

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Rapid assessment options for specific events

• Can customize to meet local needs
• Can select any combination of 1 to 4
• subplots
• Can select any combination or number
• of transects
• Choices are documented in columns on
• PLOT table, for compilation purposes

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Change Analysis

• Line Intersect Sampling of DWM does not lend
  itself to change analysis.
• DWM protocols do not track individual pieces
  estimates of change on the plot are based on the
  difference in volume/biomass/carbon at the plot
  level between time 1 and time 2.
• Variance of the change estimates may be higher
  for measurements taken on different transect
  layout.

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Example of length effect on variance
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Example of piece inclination effect on expansion
Inclination0, expansion1.0
transect plane
selection probability length10 ft
transect plane
Inclination35, expansion1.22
Inclination matters whether piece is supported or
on a slope Inclination matters for both CWM and
FWM Likely bias could be underestimating CWM by
5
selection probability length8.2 ft
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THE NITTY GRITTY 1 CWM
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THE NITTY GRITTY 2 CWM IN RESIDUE PILES
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THE NITTY GRITTY 3 FWM DUFF / LITTER DEPTHS
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THE NITTY GRITTY 4 PLOT-COND-SEGMENTS
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THE NITTY GRITTY 5 FUEL LOADING ON MICROPLOT