Fuel Constant Sets Fuel Constant Sets The equations

Fuel Constant Sets

Fuel Constant Sets The equations in FFI calculate the biomass of DWM, litter, duff and vegetation using a default set of fuel constants. Users can modify the constants for these FFI protocols/ attributes: • Surface Fuels - fine woody debris, coarse woody debris, duff and litter • Surface Fuels Alaska Duff/litter – litter, live moss, dead moss, upper duff, lower duff, lichen • Surface Fuel-Vegetation – vegetation biomass

Fuel Constant Sets are added by selecting the protocol tab you want to set the constants for and clicking the Fuel Constants menu item. Select one of the fuel options from the dropdown and enter the fuel constants in the data grid. Default FCS values are listed at the top of the data grid.

Fuel Constant Sets are added at the Sample Event level but are available for all macroplots in a database. Can be entered in English units only. FCS cannot be imported or exported in this version. You can view FCS reports in Reports and Analysis so you know what constants were used to calculate the biomass of each fuel component.

Fuel Constant Sets Fine woody debris B = (11. 64 n d 2 s a c) / Nl B = biomass n = piece count d 2 = quadratic mean diameter s = specific gravity a = non-horizontal correction c = slope correction N = number of transects l = transect length

Fuel Constant Sets Coarse woody debris B = (11. 64 Sd 2 s a c) / Nl B = biomass d = diameter s = specific gravity (by decay class) a = non-horizontal correction c = slope correction N = number of transects l = transect length

Fuel Constant Sets Duff, litter, moss, lichen B = d BD B = biomass d = component depth BD = bulk density

Fuel Constant Sets Vegetation B = c h BD B = biomass c = % cover/100 h = height BD = bulk density

Fuel Constant Sets - variability Recognize that there is a lot of variability in the different Fuel Constant Set values and it may not be worth spending a lot of time researching values specific to your area. . For example…

Fuel Constant Sets - variability Published Lodgepole Pine CWD Specific Gravity by Decay Class Source DC 1 DC 2 DC 3 DC 4 DC 5 Brown (FFI defaults) 0. 40 0. 30 Busse 0. 41 0. 31 0. 24 0. 16 0. 12 Harmon 0. 41 0. 37 0. 17 Tinker 0. 41 0. 32 0. 25 0. 17 0. 13 Nalder 0. 45 0. 52 0. 50 0. 44 Fahey 0. 35 0. 23 FPL 0. 41 FPL w/Waddell reduction factors 0. 41 0. 34 0. 29 0. 18 0. 14 Van. Wagtendonk 0. 58

Fuel Constant Sets - variability Southeast US duff data from Ottmar and Andreu Type Duff Bulk Density* Std. Dev. (tons/ac/in) FFI Default Loblolly 6. 80 b, c Slash Pine Shortleaf Pine and Hardwoods Hardwood 10. 00 2. 97 6. 88 c 6. 05 b 5. 90 b 4. 84 a 2. 52 2. 06 2. 44 2. 73 *Bulk density values with the same superscript are not significantly different. So duff bulk density values that range from 5. 90 - 6. 80 tons/ac/in are the “same” even though they differ by ~15% and in the southeast US duff bulk density is significantly lower than the FFI default.

If you have questions when you are working with FFI… User guides are available in Web, HTML and PDF versions on the FRAMES Website Post a message to our FFI Google Discussion group. Send Duncan an email or give him a call

Delivery and Support FFI on FRAMES General information, training announcements, manuals, etc. http: //frames. nbii. gov/ffi Google Discussion Group http: //groups. google. com/group/ffiemu For general technical support contact: Duncan Lutes (406) 329 -4761 dlutes@fs. fed. us software,