FIRE 323 Final

What fuels contribute to ground fire?

duff, peat, litter, organic soil horizon

What are the two limiting factors that result in smoldering combustion and inhibit flaming combustion?

1) Lack of sufficient oxygen

2) Lack of sufficient generation of gaseous vapors from pyrolysis.

What fire behavior model is best used to predict the rate of spread of a ground fire?

Operational models of ground fire do not exist

List and briefly explain at least three reasons it is important to understand ground fire behavior.

It occurs on all fires, it is the primary fire type in some ecosystems (boreal forests), it has distinct fire behavior and drivers, smoldering and ground fire represent a large component of fuel consumption

Briefly describe three drivers that contribute to smoldering ignition and combustion

fuel moisture, bulk density, fuelbed depth, mineral content, lignin content, and vectors

What time-lag class would you characterize duff based on its ability to gain and lose moisture?

1-hr

Briefly describe the difference between first-order and second-order fire effects, provide at least two examples of each.

First order fire effects occur within the first year following fire: fuel consumption, smoke production, carbon change, soil heating, post fire- tree mortality, vegetation change

Second order fire effects are delayed changes following fie: flooding, erosion, delayed tree mortality, vegetation recovery, seedling regeneration, wildlife and habitat change, longer term carbon storage.

Provide three reasons it is important to predict or monitor fuel consumption.

it directly informs smoke production, carbon cycling, relates to wildlife habitat, informs soil stability.

List the five different fuel characteristics and their units of measure that can influence fuel consumption.

chemistry (moisture composition), geometry (size/shape), quantity (loading), density (particle & fuelbed packing ratio), continuity (vertical and horizontal arrangement)

What are the two main factors that are used to predict fine fuel consumption using FOFEM?

Pre-fire total fuel load, moisture content

Which of the following scenarios would result in greater consumption during a fire burning under the same conditions/intensity?

1. A large diameter (20 in) sound log with low moisture content

2. A large diameter (20 in) sound log with high moisture content

3. A large diameter (20 in) rotten log with high moisture content

4. A large diameter (20 in) rotten log with low moisture content

A large diameter (20 in) rotten log with low moisture content

Briefly describe three benefits and three drawbacks of smoke to ecosystems.

Benefits: Smoke/char are known to increase germination rates of some plant species, smoke can serve as a cue to animals to seek refuge; smoke inversions can reduce fire behavior, water temperature, and evapotranspiration of vegetation; decrease fungal or insect pests; nutrient cycling, dispersal of microorganisms.

Negative effects: impacts on human health; nitrous oxides and sulfur dioxides impacts water quality; particulate matter and black carbon impact snow and glacial melt; contributes to greenhouse gases and global warming; impacts agricultural crops; smoke damage to property; decreased visibility.

Explain three long-term impacts of smoke on human health and well-being

mortality, reduced lung function, short children, morbidity, mental health issues.

Describe what modified combustion efficiency represents in reference to smoke productions.

proportion of combustion that is flaming. As MCE increases, CO2 increases and PM 2.5, CO, and SO2 decrease.

Calculate the estimated amount of CO₂ production (kg/ha) that results from a wildfire if you have predicted 10 Mg/ha of fuel consumption and the emissions factor for flaming and smoldering combined is 1500 kg/Mg

Provide the two aspects of smoke that are commonly modeled

distance and direction

Provide two examples of smoke models that can be used to predict smoke.

FOFEM, Bluesky Playground

Briefly describe an example of how fire damage to trees can result from each of the three heat transfer mechanisms.

convection- bole damage, needle death and bud kill

conduction- root damage

radiation- can cause pyrolysis of trees trunks and foliage

Provide the two main inputs/measurements that are required to predict tree mortality for a given species using a FOFEM type model.

bark thickness and dbh

what are the factors that can influence tree mortality that are not considered by existing models?

delayed mortality in the years following fire and reduced growth rates prior to fire due to competition or climate.

Describe a known example (i.e. results of a study) of an interaction between fire and drought and its impacts on post-fire tree mortality.

Based on a study of redwood forests, list and explain the three stand characteristics that were found to influence tree mortality following wildfire.

Explain at least three characteristics of a species that can influence post-fire regeneration.

mode of reproduction (serotiny and seed viability), tree size (bigger trees produce more seeds), seed mass (larger seeds survive better), seed dispersal (seeds with larger wings can disperse further)

Draw or clearly describe the commonly observed pattern of post-fire regeneration density with distance from a living edge of a forests of non-serotinous tree species.

Explain some commonly observed patterns of how post-fire regeneration density in non-serotinous species changes with fire severity (low, moderate, and high).

Regen density is low at both LOW fire severity & HIGH fire severity.

Regen is higher at moderate fire severity.

Based on a model of post-fire conifer regeneration developed based on observations following numerous wildfires in California (Shive et al. 2018), provide the top three factors found to influence the probability of post-fire regeneration.

Communicate at least two reasons understanding post-fire tree regeneration is needed.

1) Understanding post-fire regen is vital because it is essential for the long-term persistence of forest ecosystems.

2) Post-fire regen knowledge is important for developing strategic land management with applied understanding of how fire affects the landscape.

Which of the following statements is most correct for post-fire resprouting in redwood (but likely other species too)?

1. Increased fire damage results in decreased resprouting biomass

2. Increased fire damage results in increased resprouting biomass

3. As fire damage increases resprouting biomass increases at first and then decreases above some intermediate fire damage

Increased fire damage results in increased resprouting biomass

Describe the two main soil characteristics that influence soil heating during a fire

Soil Depth: the heating of soil declines rapidly with increased depth.

Soil Moisture: moisture content dampens heat transfer to soil, buffering temperatures

Explain how hydrophobicity changes with fire intensity and describe the potential impacts of hydrophobic soils following a fire

Hydrophobicity is influenced by soil heating during fire. Fire intensity can influence the depth and severity of hydrophobic the layer becomes post-fire.

Provide at least three soil nutrients or minerals that can increase following fire.

ammonium and nitrate, soil pH

What is the most common change in soil pH following wildfire?

Usually increases

Briefly explain two reasons why the strict use of a lethal temperature thresholds (e.g. 60 degrees C for 1 sec) is a limiting approach.

Describe the impact of high severity fire on snowpack dynamics following wildfire.

More snow is able to accumulate because of the lack of interception, earlier peak snowpack. Snow melts more rapidly (more direct sun exposure).

Explain two potential benefits and two potential drawbacks of fire to aquatic ecosystems.

Benefits

1) provides large complex wood structures that provide habitat

2) smoke cover can decrease temperatures in rivers and streams

Drawbacks

1) increase sedimentation

2) decrease dissolved oxygen concentration (leading to fish kills)

Provide two examples of how fire can negatively influence the physical and mental well-being of humans

Death and PTSD

Provide two examples of how fire can positively influence the physical and mental well-being of humans.

Soliphilia, connection to culture

Define what the terms solastalgia an soliphilia mean in reference to the presence or absence of fire to humans/communities.

Soliphilia- the love or responsibility a person feels for a particular place/home (perhaps while taking care of it with a prescribed or cultural burn)

Solastalgia- emotional distress due to changes in a particular place (home) while still being present in that particular location (perhaps because it burned down)

Describe the potential impacts of fire on cultural, economic, or other aspects of human communities.

What are the three unique measures of landscape fire behavior?

List and briefly describe three of the landscape fire behavior models and decision support tools commonly used by managers.

Create a chart that communicates how the different landscape fuel models are used to estimate fire behavior across the numbers of fires and weather scenarios.

List at least five of the data layers needed from LANDFIRE to model landscape fire behavior.

Provide the six recommendations from FBAN/Fire planner, Eamon Engber, when modeling landscape fire behavior on a wildfire incident.

List and briefly describe the two types of next generation fire behavior models.

Select all of the following that are considered physics-based fire models

1. FIRETEC

2. FLAMEMap

3. WFDSS

4. WFDS

5. IFTDSS

Explain two advantages and two disadvantages of next generation fire behavior models compared to the Rothermel fire behavior model at this time.

Provide two specific impacts of tree spatial patterns on fire behavior and effects based on simulations generated from computational fluid dynamics models.

What is QUIC-FIRE and what is a current use of this model?

Provide a definition for a two-way fire-atmosphere model and give the name of one that is in common current use.

Based on previous research/case studies, provide a major finding that describes the potential utility of a fire-atmosphere model.

Describe the two types of wildland urban interface. Which one of these tends to result in a higher loss of structures, based on existing research?

Communicate a concerning trend of wildland urban interface development in the United States and provide a couple of reasons this trend is concerning.

Provide four known home-hardening related characteristics that are known to reduce structure loss during a wildfire.

What are two of the potential benefits of treating the broader landscape within and around the wildland urban interface?

In some studies conducted in California, there was not a clear benefit of defensible space, provide two reasons that defensible space (clearing of vegetation around a structure) may not be sufficient to reduce the probability of structure loss during a wildfire

Describe three known trends in wildfires that are partially attributed to increasing temperatures associated with human-caused climate change.

Provide three factors that are potentially contributing to climate-change related increases in wildfire activity within the western US.

Most area burned in California forests is attributed to what percentile fire size classes?

1. < 90^th percentile

2. 90-95^th percentile

3. 95^th-98^th percentile

4. 99^th percentile

Most of the area burned in recent large wildfires is burning at what severity level?

1. Unburned to very low severity

2. Low to moderate severity

3. High severity