Deck 13: Wildfires

Question 1

Presently in Canada most wildfires are started by

A) people.
B) lightning.
C) asteroids.
D) spontaneous combustion.
E) rockfalls.

Answer 1

A

Question 2

Which of the following is NOT a natural service function of wildfires?

A) an increase in the nutrient content of a soil
B) the release of seeds from lodgepole pines
C) maintenance of stand age diversity
D) removal of species that have become too abundant in the forest ecosystem
E) removal of diseased, dying trees

Answer 2

D

Question 3

Flaming combustion differs from smouldering combustion in that it

A) is a slow process.
B) is a low temperature of fuel to thermal energy.
C) does not require rapid pyrolysis.
D) leaves a large amount of residual unburned material.
E) only occurs during drought conditions.

Answer 3

D

Question 4

On a scale of decades to centuries,the most important condition for initiating large wildfires is

A) human carelessness.
B) volcanic activity.
C) lightning.
D) the climate.
E) forest composition.

Question 5

Which of the following best describes what happens during the preignition process in wildfire development?

A) Fuel is heated, it loses water and is ready to be ignited.
B) Fuel at the front of a fire is ignited.
C) Fuel gains carbon dioxide and is ready to burn.
D) Gases heat and expand into fuel.
E) Gases cool and contract to produce fuel.

Question 6

Fire requires the following three conditions

A) fuel, heat, and lightning.
B) oxygen, dry conditions and lightning.
C) fuel, oxygen, and heat.
D) fuel, oxygen, and dry conditions.
E) oxygen, dry conditions, and heat.

Question 7

An increase in wildfires at the end of the Pleistocene Epoch

A) occurred mainly in Europe.
B) was associated with an increase in volcanic activity.
C) was associated with the first appearance of grass as a fuel.
D) was associated with the first appearance of man in the northern hemisphere.
E) was likely due to warmer and drier climate than present.

Question 8

Which of the following factors most influences the spread,intensity and form of a wildfire?

A) drought
B) humidity
C) temperature
D) wind
E) precipitation

Question 9

Were there wildfires before humans? (Choose the best answer.)

A) Yes, but they were relatively very small because they had natural causes.
B) Yes and they were caused by natural igniters such as lightning strikes or asteroid impact.
C) No. Humans are the only cause of wildfires.
D) No. There weren't trees before humans and so there couldn't be wildfires.
E) Maybe, but there is no record to find out.

Question 10

Which of the following describes radiation,which is one kind of heat transfer process during the combustion phase of wildfire?

A) heat transfer though electromagnetic waves
B) transmission of heat through molecular contact
C) heat transfer by the movement of heated gases driven by temperature differences in air
D) heat transfer by endothermic chemical reactions
E) heat transfer by splitting large fuel molecules into smaller ones

Question 11

The term fire regime refers to

A) how fires are managed in an area.
B) the pattern of fire activity in an area.
C) the natural service functions of wildfires.
D) techniques of fire suppression.
E) linkages of fires with climate.

Question 12

Large wildfires in southern California

A) are increasing in severity and intensity due to fire suppression.
B) rarely result in loss of property.
C) will likely become smaller in the future due to increased urbanization.
D) have increased greatly in number.
E) have decreased greatly in number.

Question 13

When combustion takes place

A) ignition occurs.
B) the fuel is chemically degraded.
C) energy is absorbed.
D) pyrolysis occurs.
E) volatile gases are produced.

Question 14

The factors that contributed to the severity of the fires in British Columbia in 2003 and 2009 were

A) lightning and an overabundance of forest fuel.
B) prolonged drought and lightning.
C) prolonged droughts and an overabundance of forest floor fuel.
D) consistently windy conditions.
E) ineffective fire suppression.

Question 15

Which of the following is NOT released during wildfire?

A) heat
B) water vapor
C) oxygen
D) carbon dioxide
E) light

Question 16

Why are wildfires becoming more disastrous?

A) Government resources for firefighting are insufficient.
B) Past fire-suppression techniques have increased the amount of fuel available.
C) The climate is getting drier as global temperatures rise.
D) The frequency and severity of lightning storms is increasing.
E) More people are moving to areas at risk for fire hazards.

Question 17

Wildfire scientists and firefighters classify fire behaviour according to

A) the wind speed at the fire site.
B) the amount of precipitation that has fallen in the region.
C) the humidity at the fire site.
D) the layer of fuel that is allowing the fire to spread.
E) the species of vegetation that is being burnt.

Question 18

Hot fires that scorch dry,coarse soil may lead to

A) the formation of a water-repellent layer.
B) decreased surface runoff.
C) increased soil strength and fewer landslides.
D) increased water infiltration.
E) more debris flows.

Question 19

A fire is considered extinct when

A) you can no longer see flames.
B) combustion, including smouldering, ceases.
C) smoke is no longer observed.
D) flaming combustion ceases.
E) the the source of combustion is removed.

Question 20

In Canada,the geographic area that is most at risk from forest fires is

A) Atlantic Canada.
B) Southern Ontario.
C) the boreal forest.
D) Nunavut.
E) Prince Edward Island.

Question 21

If you were a geologist,what evidence might you find (in rocks or sediments)that would indicate that wildfires had occurred in the past?

A) fossilized pine cones
B) grass pollen
C) clay layers
D) charcoal
E) oak bark

Question 22

If wildfires were eliminated,jack pines would go extinct.Why?

A) Wildfires remove parasites from jack pine trees, which would otherwise kill the tree.
B) Jack pine bark is resistant to fire, allowing it to flourish when other species are removed by fire.
C) Jack pine cones open only after a tree has been burned.
D) Jack pines rely on ash in the soil for nutrients.
E) Other tree species outcompete jack pines in regions where fire is rare.

Question 23

Under what conditions would a fire in a canyon advance down slope?

A) if the slope is south-facing
B) if the canyon has more fuel downslope
C) if there are lightning storms in the area
D) if the fire is driven downslope by the wind
E) if the area has experienced a recent drought

Question 24

Which of the following controls the timing of seasonal wildfires in Southern California?

A) intensity of Santa Ana winds
B) rainfall the previous winter
C) rainfall the previous autumn
D) sea surface temperatures just offshore
E) logging schedules

Question 25

How can wildfires maintain or increase diversity in a forest?

A) by reducing the amount of fuel available for future fires
B) by opening gaps in the forest canopy
C) by killing off invasive species
D) by killing off soil microorganisms
E) by killing off pine beetles

Question 26

Why have wildfires become more hazardous in southern California in the past hundred years?

A) Hot, dry Santa Ana winds have become more extreme.
B) El Niño conditions have become more severe.
C) Flammable vegetation in yards has increased.
D) More people have moved to fire-prone areas.
E) More forested slopes have been clearcut.

Question 27

Which of the following processes is most important to keep the population of pine beetles in check?

A) Hot temperatures in the summertime kill adult beetles.
B) Prolonged drought in the summertime kills beetle larvae.
C) Infested trees secrete a substance poisonous to beetles.
D) Infested trees host a symbiotic fungus that is poisonous to beetles.
E) Cold temperatures in the wintertime kill beetle larvae.

Question 28

Which of the following groups of animals is least likely to benefit from wildfires?

A) fish in streams
B) grazing mammals
C) burrowing rodents
D) birds
E) insects

Question 29

Which type of combustion takes place at the highest temperatures?

A) flaming combustion
B) glowing combustion
C) conduction combustion
D) smouldering combustion
E) radiation combustion

Question 30

Imagine a wildfire occurs in a watershed that provides drinking water to a community.What is the most likely impact on the drinking water supply?

A) The amount of water in the reservoir will stabilize due to rapid runoff.
B) Carbon from the ash will act as a natural filtration system for the water.
C) Water quality will increase because less debris will get into the reservoir.
D) Parasites in the water supply will increase, making the water unsafe to drink.
E) Erosion from slopes cleared by fire will decrease water quality.

Question 31

Which of the following topographic situations is likely most susceptible to wildfire in western Canada?

A) a south-facing slope
B) a north-facing slope
C) a west-facing slope
D) an east-facing slope
E) a northeast-facing slope

Question 32

How can fire increase post-fire erosion?

A) by removing dead wood that was holding soil in place
B) by creating a hydrophobic layer above which the soil erodes
C) by baking soil and creating an impervious surface layer
D) by increasing the amount and intensity of post-fire rainfall
E) by accelerating the breakdown of rock into erodible soil

Question 33

Which of the following types of fires releases the most energy per unit length of fire front?

A) surface fire
B) intermittent crown fire
C) ground fire
D) continuous crown fire
E) tree top fire

Question 34

What is the greatest risk during a well-planned,well-researched prescribed burn?

A) The amount of fuel will change.
B) Fire fighting equipment will break down.
C) Nearby towns will have to be evacuated.
D) The weather will change.
E) Lightning strikes will increase the fire's area.

Question 35

Which of the following is a good reason for a prescribed burn?

A) Too much fuel is available and needs to be removed to prevent a larger fire.
B) Animals that are invading a habitat need to be moved to another location.
C) Shrubland needs to be cleared for new housing.
D) Vegetation on hillsides needs to be cleared before the rainy season.
E) The ground needs to be fused to prevent erosion.

Question 36

In 1988,the natural-burn policy in Yellowstone National Park resulted in

A) the destruction of the park ecosystem.
B) the death of 15 firefighters.
C) new fire-suppression policies.
D) a ban on all camp fires.
E) revitalized park ecosystems.

Question 37

A fire in which the tops of most of the trees are burned is called a/an

A) surface fire.
B) intermittent crown fire.
C) ground fire.
D) continuous crown fire.
E) tree top fire.

Question 38

Wildfires transfer heat mainly by

A) conduction.
B) convection.
C) radiation.
D) latent heat transfer.
E) sensible heat transfer.

Question 39

The aim of fire management is to

A) suppress all wildfires to protect the economic value of forests.
B) protect all human infrastructure regardless of economic value.
C) control fires to benefit ecosystems while protecting people and property.
D) remove fuel by letting natural wildfires burn until put out by natural processes.
E) determine where prescribed burns would be most beneficial.

Question 40

What is the first process that occurs in the combustion phase of fire?

A) preheating
B) pyrolysis
C) flaming combustion
D) ignition
E) extinction

Question 41

Surface fires can burn the soil just under the ground surface.

Question 42

Crown fires can spread independently of surface fires.

Question 43

Wildfires on steep slopes preheat fuel downslope from the flames.

Question 44

Lower humidity can result in an increase risk of wildfires.

Question 45

Fire can increase the nutrient content of soil.

Question 46

Santa Ana winds are associated with wildfires in western Canada.

Question 47

Fire regime refers to the pattern of fire activity in an area.

Question 48

Ash is non-combustible.

Question 49

Fire suppression policies over the past half century have reduced wildfire risk.

Question 50

Pre-ignition processes release heat.

Question 51

In Canada,there typically is no winter wildfire activity.

Question 52

Hydrophobic soil layers formed by fire disintegrate when the temperature cools back to normal.

Question 53

Only people can prevent forest fires.

Question 54

Aboriginal peoples used fire as a hunting tool.

Question 55

In Canada,the total area burned by wild fires in the first half of the 20th century was less than the total area burned in the second half of the 20th century.

Question 56

Many areas in California are at risk from multiple types of natural disasters.Which of the following steps to protect your home from fire might increase your risk of damage from earthquakes?

A) thinning trees and brush near your house
B) storing flammable materials outside and away from major structures
C) installing multi-pane windows
D) cleaning your chimney regularly
E) using clay tiles for roofing

Question 57

Given the same wind velocity,wildfires move faster up slope than they move down slope.

Question 58

The purpose of a fire break is to steer a fire uphill.

Question 59

When plant material burns,carbon dioxide,water vapour,and heat are released.

Question 60

Fire can trigger the release of seeds.

Question 61

The 2011 Slave Lake wildfire was started by lightning.

Question 62

What is flaming combustion?

Question 63

Houses on hillsides are usually safe from wildfires because the fires cannot climb hills.

Question 64

Wildfires can generate their own wind.

Question 65

Though the number of large wildfires in California has not changed significantly in the past few hundred years,their size,intensity,and effect on people has.Why?

Question 66

Nova Scotia is the only Canadian province to never have experienced a wildfire.

Question 67

How does wildfire affect fish and other aquatic species?

Question 68

The boundary between prairie grasslands and boreal forests in Canada is likely to move north as climate warms.

Question 69

What happens to vegetation when it is preheated?

Question 70

Under what conditions do wildfires develop?

Question 71

Animals are generally able to escape all but the fastest-moving wildfires.

Question 72

The fire season in Canada is longer than in the United States.

Question 73

How does the fire season in Canada differ from the fire season in the United States?

Question 74

What are the three phases of wildfires?

Question 75

Erosion is a common consequence of wildfires.Why?

Question 76

What is pyrolysis?

Question 77

Some of the heat in a fire is transferred by radiation.

Question 78

Describe one example of a plant that has evolved to utilize fire in its life cycle.

Question 79

Large wildfires that occur regularly in a location every 50 to 100 years will not become established unless sufficient fuel is present.

Question 80

In central British Columbia,100% of the lodgepole pine is expected to die due to beetle infestation by the year 2017.