F.O.F.E.M. 5First Order Fire Effects Module

Adapted from:Missoula Fire Sciences Laboratory

Systems for Environmental Management

• “First-order effects” are the immediate consequences of a fire.

• Second-order effects??– Longer term effects– Involve interaction with other agents

• Vegetation dynamics, insect-caused mortality, climate and weather, erosion– Examples: Tree regeneration, plant succession, site productivity

Fuel consumptionSmoke production

Tree mortalitySoil heating

What is a “first-order” effect?

FOFEM 5 is used to…

Quantify Fire Effects (Severity) vs. Fire Behavior (Intensity).

• Assess wildfire and prescribed fire impacts.– Ex. how many trees can we expect to survive?– Ex. how many centimeters of soil were exposed to lethal

temperatures?

• Predict the effects of a current fire.– Ex. How much smoke will be produced?

• Design fire and silvicultural prescriptions.– Ex. Under what moisture conditions can we reduce duff by 30%?– Ex. How many acres can burn without exceeding particulate

limits?

How FOFEM works

• FOFEM compiles fire effects data and models from the literature.

• FOFEM 5 automatically uses the best available equation or model.

• Creates default inputs for vegetation and fuel types – so the user doesn’t have to collect data.

FOFEM 5: Tree mortality

• By species and size• 207 tree species• Estimates bark thickness from species and

diameter. • Predicts mortality from bark thickness, crown

scorch.• Mortality algorithm does not account for:

– season of burn, post-burn insect attack, drought, or resid. time

Tree mortality: inputs

Set fire severityChoose region

Define tree list

Set fire intensity

Select “mortality”

Tree mortality: outputs

PROBABILITY OF MORTALITY FOR EACH SPECIES/DIAMETER

Species Diameter Number Prob Mort Equ Code (inch) Trees Mort Number _____________________________________________

PSEMEN 1 300 1.00 1 PSEMEN 8 100 0.39 1 PINPON 20 25 0.07 1

STAND TREE MORTALITYPercent mortality: 49 Number of trees killed by the fire: 341Average tree diameter of firekilled trees: 1.9 Percent mortality for trees 4+ in DBH: 23 Total prefire number of trees: 425

FOFEM 5: Fuel consumption

• Inputs needed:– Fuel load by size class

(1,10,100,1000 hr fuels, etc.)

– Fuel moisture

• Outputs generated:– Fuel consumption by size

class– Post-burn fuel load

Fuel Consumption: inputs

• Fuel load

Select region & classifica-tionSelect

cover type

Select fuel category

Set fuel load adjustments

Select “Fuel”

Fuel Consumption: inputs

• Fuel load

Set percent 3”+ load that is rotten

Set percent crown fuel burned

Set season of burn

– Or you can input fuel load data directly.

Fuel Consumption: inputs

• Fuel moisture– Moisture condition (very dry, dry, moderate, wet)Choose

moisture condition

Or, you can input fuel moisture directly

Fuel Consumption: outputs

• Graph and report of pre-burn and post-burn fuel data.

Fuel Graph

Preburn Load Consumed Load Remaing Load

0

20

10

30+

tons

Litter 0-1/4 1/4-1 1-3 3+ Duff Herb Shrub Foliage Branch

FOFEM 5: Smoke production

• Predicts emission production rate.

• Gives proportion of flaming versus smoldering combustion

• Estimates production of:– PM10: affects visibility– PM2.5: trapped in human lungs

– CO2, CH4, NOx, SOx, CO: greenhouse gases

FOFEM 5: Smoke production

• Inputs needed:– Fuel load by size class– Fuel moisture– (Same as fuel consumption)

• Outputs generated:– Smoke production over time

for each emission molecule– Flaming and smoldering

combustion

Select “Smoke”

Smoke emissions: outputs

• Graph and tabular report of smoke production by component.

FOFEM 5: Soil heating

• Soil heating model:– predicts time,

temperature, depth profiles

Soil heating: inputs

• Soil heating inputs are the same as fuel consumption, with two additions…

Select “Soil”

Choose soil texture

Set soil moisture content (percent)

Soil heating: outputs

• Graph and tabular report of soil heating by depth.

25

50

75

100

0

Temperature

(C)50 100 150 200 250 300 350 400 450 500minutes

Max Tmp: 61(c) Post Fire Duff Depth: 1.31(in) Soil Moist:10.00% Type:Coarse-LoamLines represent temperatures at 1 centimeter intervals, starting at soil surface.

Soil Heating

FOFEM 5: Strengths

• Simple, easy to learn and use.

• Can be used for a variety of purposes.

• Accommodates variable level of input detail.

• Combines physical and empirical models from scientific research.

• Creates reports, graphs and data tables that can be incorporated into other documents, including GIS.

FOFEM: Weaknesses

• Outputs are only as good as the algorithms and default data in the fire literature.– Some defaults are only based on 2-3 studies– Some inputs are general (ex. moisture = low, medium,

high).

• Assumes a continuous, complete burn (not patchy), so it may overestimate the effects.

• Does not estimate second order effects (ecological interactions)

• Forest-centric – only a few grass and shrub models