230 likes | 382 Views
Proposed FIA DWM protocol. July 2009. 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. Why a P2-DWM protocol?.
E N D
Proposed FIA DWM protocol July 2009
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 Why a P2-DWM protocol?
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) Why a new DWM protocol design effort?
Volume, biomass, carbon • Fuel Loading – Biomass per acre • Wildlife/Ecological – CWM length per acre & number of logs by large-end diameter FIA Information Needs
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. Results of Analyses
Three Protocol Options • Protocol Improvements How does the proposed design integrate P2 and P3 DWM?
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. 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. 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. PROTOCOL OPTIONS
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. Measured variables
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. Protocol Improvements
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). Proposed transect design
Proposed DWM Protocol Subplot 360° Macroplot 2 CWD transects FWD transects 180° Litter and duff depth Extra transect on subplot option 1 270° 90° Longer transect length on macroplot option 45° 315° 3 4 135° 225°
Minimizes orientation bias • Reduces multiple intersections of the same piece by different transects • Gain in field efficiency • P2 / P3 integration Strengths of the proposed transect design
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 Rapid assessment options for specific events:
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. Change Analysis
Inclination=0°, expansion=1.0 transect plane selection probability length=10 ft transect plane Inclination=35°, expansion=1.22 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% Example of piece inclination effect on expansion selection probability length=8.2 ft