Chapter 18: Fire Flashcards
(166 cards)
1
Q
This is an integral part of many ecosystems
A
Fire
2
Q
Fire was once thought to be only this
A
Destructive
3
Q
This has greatly changed many ecosystems
A
Fire suppression
4
Q
This is the study of fire in ecosystems
A
Fire ecology
5
Q
What are four focuses of fire ecology?
A
- Origin of natural fires; 2. Factors influencing spread and intensity of fire; 3. Relationship of fire and ecosystems; 4. Use of controlled fire for ecosystem health
6
Q
What are the five concepts that form the basis for fire ecology?
A
- Fire dependence; 2. Fire history; 3. Fire regime; 4. Fire effects; 5. Fire adaptations
7
Q
This describes the reliance of ecosystems on fire
A
Fire dependence
8
Q
This describes the past association of regions with fire
A
Fire history
9
Q
This describes the intensity and frequency of fire
A
Fire regime
10
Q
This describes the impacts of fire on soil, vegetation and hydrology
A
Fire effects
11
Q
This describes the evolution of fire-related species traits
A
Fire adaptations
12
Q
What are the three types of systems related to fire?
A
- Fire-dependent systems; 2. Fire-sensitive systems; 3. Fire-independent systems
13
Q
In these systems, fire plays an essential role and its exclusion leads to major changes in the ecosystem
A
Fire-dependent systems
14
Q
Are many plants and animals in fire-dependent systems fire-adapted?
A
Yes
15
Q
Is plant reproduction in fire-dependent systems often stimulated by fire?
A
Yes
16
Q
Are fire-dependent systems less fire-prone and flammable?
A
No
17
Q
Does plant architecture in fire-dependent systems hinder fire spread?
A
No
18
Q
In these systems, fire effects are detrimental to the ecosystem
A
Fire-sensitive systems
19
Q
In fire-sensitive systems, does frequent fire cause a shift to less or more fire-prone vegetation?
A
More fire-prone
20
Q
Do fire-sensitive species have fire adaptations?
A
No
21
Q
Does fire-sensitive ecosystem structure inhibit the spread of fire?
A
Yes
22
Q
In these systems, fire plays little or no role
A
Fire-independent systems
23
Q
What are three conditions that can make a system fire-independent?
A
Too cold, too dry, too wet
24
Q
How many global ecosystems depend on fire?
A
More than half
25
What are five patterns of fire described by fire regimes?
Fire type, intensity, severity, frequency, and seasonality
26
What are three patterns of fire types?
Ground, surface, crown
27
This fire pattern describes the energy release of fire
Fire intensity
28
This fire pattern describes the impact of fire on an ecosystem
Fire severity
29
How is fire severity often measured?
As plant mortality
30
This fire pattern measures fire return interval
Fire frequency
31
This fire pattern describes the time of year when fire is most common
Fire seasonality
32
The frequency of fire varies with this
Geography
33
What three components are required for fire?
Fuel, ignition source, oxidizing agent
34
Forests provide a diversity of these for fire
Fuels
35
What are four types of fire fuel in forests?
Trees, woody debris, grasses, litter
36
What are the two different types of forest ignition sources?
Natural and human
37
What are two natural forest ignition sources?
Lightning and volcanoes
38
What are three human forest ignition sources?
Campfires, cigarettes, arson
39
The atmosphere provides sufficient amounts of this as an oxidizing agent
Oxygen gas
40
What are four factors that determine fire behavior?
1. Forest fuel types; 2. Fuel moisture; 3. Topography; 4. Weather
41
What are four types of forest fuels?
Surface, ground, ladder and aerial fuels
42
What are four types of surface fuels in forests?
Woody debris, litter, grasses, small shrubs
43
This type of forest fuel is below the surface litter
Ground fuel
44
What are three types of ground fuels in forests?
Humus, peat, roots
45
What are three types of ladder fuels in forests?
Small trees, hanging branches, vines
46
This type of forest fuel is suspended in the forest canopy
Aerial fuel
47
What are the three types of wildfires?
Surface, ground, and crown fires
48
This type of wildfire burns surface fuels
Surface fire
49
Are surface fires hot and rapidly moving?
Yes
50
This soil layer is not completely consumed in a surface fire
O layer
51
What type of vegetation is killed by surface fires?
Smaller woody vegetation
52
This type of wildfire is fed by roots and buried organic matter
Ground fire
53
Are ground fires rapid-moving and high intensity?
No
54
Can ground fires smolder for long periods?
Yes
55
Are ground fires often highly destructive?
Yes
56
Heat exposure from ground fires destroys these three forest components
O layer, soil biota, plants
57
This type of wildfire usually starts as a surface fire, then spreads up the canopy via ladder fuels
Crown fire
58
Can crown fires spread quickly from crown to crown?
Yes
59
Are crown fires highly destructive to plant biomass?
Yes
60
Are crown fires more common in hardwoods or conifers?
Conifers
61
Fuels with this moisture level are highly flammable
< 10%
62
Which burns better, dead vegetation or living vegetation?
Dead vegetation
63
Which burns better, green conifers or green broadleafs?
Green conifers
64
This topographical feature influences fire behavior
Slope
65
Fires do this to uphill fuels, making them ignite faster
Preheat uphill fuels
66
This debris can ignite more fuels on a slope
Rolling burning debris
67
Do northern or southern aspects burn hotter?
Northern
68
Why do northern aspects burn hotter?
More vegetation
69
Fires spread rapidly in these two types of topographical features
Canyons and valleys
70
What four weather factors act in concert to affect fire behavior?
Temperature, relative humidity, wind, precipitation
71
Weather affects these two aspects of a fire
Intensity and spread
72
Hot temperatures increase this aspect of fuels
Ignitability
73
What are five effects of wind on fire behavior?
1. Dries fuel; 2. Carries oxygen; 3. Affects fire direction; 4. Starts spot fires; 5. Shapes burn area
74
At this relative humidity, fuels are more likely to ignite
< 30%
75
This relative humidity is a dangerous fire risk
< 20%
76
What are two affects of heavy precipitation on fires?
Wetting fuels and extinguishing burning fires
77
What are the three scales at which fires are influenced?
Flame, wildfire, fire regime
78
What are three abiotic effects of fire on soil?
1. Soil temperature; 2. Soil water and hydrology; 3. Soil chemistry
79
How does fire affect soil temperature?
By removing O layer and opening soil
80
How does fire change soil temperatures by day and night?
Hotter day temperatures and cooler night temperatures
81
What are three things that fires reduce to increase the amount of water than gets to the soil?
By reducing litter, interception and transpiration
82
Fires open soils and increase this in soil water
Evaporation
83
Can fires create water-repellent soils?
Yes
84
Fires on slopes can increase this
Runoff/erosion
85
What are three ways fire causes nutrient loss?
Oxidation, volatilization, erosion
86
What counteracts some nutrient loss from fire?
Charcoal
87
Do soils become more basic or acidic with fire?
Basic
88
Fire can alter these two soil aspects by affecting clays
Texture and structure
89
These flora are typically destroyed by fire
Fire-intolerant flora
90
Some fire-intolerant flora produce these
Fire-activated seeds
91
These flora resist some fire damage and may resprout after fire
Fire-tolerant
92
These flora suffer little damage from fire
Fire-resistant
93
What animals are most vulnerable to fire?
Small animals with limited mobility
94
What causes most large animal mortality during a fire?
Smoke
95
The biggest effects on animals from fire are due to this
Habitat impact
96
These animals are vulnerable to fire when nesting
Birds
97
Birds profit from more of this after fire
Prey
98
These animals flee or take cover from fire
Mammals
99
These animals hide from fire in mud or water
Herps
100
These organisms vary in fire resistance
Microbes
101
These provide refuge from fire for microbes
Deeper soils
102
Microbes profit from these soil conditions after fire
Warm, wet soils
103
104
What are six purposes of prescribed fire?
1. Hazard reduction; 2. Hardwood control; 3. Site preparation; 4. Forage improvement; 5. Disease control; 6. Accessibility/aesthetics
105
This purpose of prescribed fire reduces fire risk by reducing litter
Hazard reduction
106
This purpose of prescribed fire kills undesirable plant species
Hardwood control
107
This purpose of prescribed fire destroys debris and exposes bare soil
Site preparation
108
This purpose of prescribed fire promotes grass and forbs
Forage improvement
109
This purpose of prescribed fire controls some bacterial and fungal pests
Disease control
110
This purpose of prescribed fire opens stands
Accessibility/aesthetics
111
What are eight factors to be considered when planning a prescribed burn?
1. Weather; 2. Fuel moisture timelag; 3. Season; 4. Burn method; 5. Ignition method. 6. Smoke management; 7. Burn plan; 8. Burn evaluation
112
Knowledge of this is key to burning and mandatory for proper smoke management
Weather
113
What are four weather elements to consider when planning a burn?
Temperature, humidity, precipitation, wind
114
What is the best temperature for burning in the winter?
20-60 degrees
115
What is the best temperature for burning in the summer?
> 80%
116
What is the best humidity for burning?
30-55%
117
What wind speed is best for burning?
3-5 mph within forest
118
What is the best rainfall for a burn?
0.5-1.0", one week before burn
119
What is the best Keetch-Byram Drought Index for burning?
250-400
120
This is key to predicting fire behavior
Fuel moisture timelag
121
These fuels take 1 hour for 2/3 of the dead fuel to respond to atmospheric moisture
Flashy fuels
122
Fuels this size take 10 hours for 2/3 of the dead fuel to respond to atmospheric moisture
1/2 inch diameter
123
Fuels this size take 100 hours for 2/3 of the dead fuel to respond to atmospheric moisture
3 inch diameter
124
Fuels this size take 1000 hours for 2/3 of the dead fuel to respond to atmospheric moisture
8 inch diameter
125
What are the two prescribed fire seasons?
Cool and growing season
126
These prescribed burns are held late winter to early spring
Cool season burns
127
What is the purpose of cool season burns?
Reducing forest litter
128
These prescribed burns are held from early spring to late summer
Growing season burns
129
What is the purpose of growing season burns?
Killing vegetation
130
Which burns hotter, growing season or cool season burns?
Growing season burns
131
Which is most common for wildlife management, growing season or cool season burns?
Cool season burns
132
These are used to achieve specific burning goals
Different burn methods
133
Burn methods must correlate with these three factors
Weather, fuels, terrain
134
What are four burning methods?
Backfire, headfire, flankfire, spotfire
135
This burning method is started at a firebreak/road and headed directly into the wind
Backfire
136
This burning method is the least intense and most predictable
Backfire
137
This burn method has a narrow burning zone with short flame lengths
Backfire
138
This burning method has a slow rate of spread and burns deep
Backfire
139
This burning method has a low smoke output
Backfire
140
What are seven characteristics of the backfire burning method?
1. Low intensity; 2. Predictable; 3. Narrow burning zone; 4. Short flame length; 5. Slow rate of spread; 6. Burns deep; 7. Low smoke output
141
Where is a fire started in the backfire burning method?
Firebreak or road
142
How does a backfire travel in relation to the wind?
Directly into wind
143
This burning method is the most intense and unpredictable
Headfire
144
This burning method has a wide burning zone with long flame lengths
Headfire
145
This burning method has a fast rate of spread and burns shallowly
Headfire
146
This burning method has a high smoke output
Headfire
147
What are seven characteristics of a headfire?
1. High intensity; 2. Unpredictable; 3. Wide burning zone; 4. Long flame lengths; 5. Fast rate of spread; 6. Burns shallowly; 7. High smoke output
148
These two burning methods are intermediate intensity
Flankfire and spotfire
149
In this burning method, fire spreads at right angle to the wind
Flankfire
150
This burning method is limited to steady wind conditions
Flankfire
151
This burning method requires careful coordination
Flankfire
152
This burning method is used for securing flanks of back or head fires
Flankfire
153
This burning method is useful in shifting winds
Spotfire
154
In this burning method, spots merge to form a strip headfire
Spotfire
155
What device is used to produce spotfire?
Delayed Aerial Ignition Device
156
There are many ground and aerial methods for this
Ignition methods
157
Proper burning must manage this
Smoke
158
What are four examples of smoke sensitive areas?
Roads, schools, hospitals, nursing homes
159
Burners are liable for this
Smoke damages
160
This will lift smoke during a burn
Correct weather
161
All burns should have this
Written plan
162
What are three things that should be included in the written burn plan?
1. Burn unit location/description; 2. Burning objectives/instructions; 3. Desired and actual weather conditions
163
Burn plans should have a detailed map of this
Burn unit
164
What are four things that should be included in a burn unit map?
Control lines, terrain, wind, landowners
165
166
What are two things to check for when evaluating a burn in spring?
New growth and bark beetles
