Wildfires

Question 1

What is a wildfire?

Answer 1

A self-sustaining, rapid, high-temperature biochemical oxidation reaction.

Question 2

What is ash made of?

Answer 2

Mineral compounds.

Question 3

What is soot made of?

Answer 3

Unburned carbon.

Question 4

What are the requirements for a wildfire?

Answer 4

1. Fuel
2. Oxygen
3. Heat

Question 5

[True/False] Wildfire reverses the process of photosynthesis.

Answer 5

True.

Question 6

What are the three phases of a wildfire?

Answer 6

1. Preignition
2. Combustion
3. Extinction

Question 7

Define preheating.

Answer 7

Fuel loses water and other volatile compounds.

Question 8

Define pyrolysis.

Answer 8

Processes that chemically degrade fuel.

Question 9

What happens during preignition?

Answer 9

Fuel achieves temperature and water content favorable to ignition.

Question 10

Does ignition always lead to wildfires?

Answer 10

No, sufficient fuel must be present.

Question 11

What are the two types of combustion occurring during a wildfire?

Answer 11

Flaming combustion and smoldering combustion.

Question 12

What is extinction?

Answer 12

The point at which combustion ceases.

Question 13

What three factors explain the behavior of a large wildfire?

Answer 13

1. Fuel
2. Topography
3. Weather

Question 14

What weather factors affect wildfires?

Answer 14

1. Temperature
2. Relative humidity
3. Atmospheric stability
4. Wind speed/direction
5. Precipitation

Question 15

When do fires usually burn most intensely?

Answer 15

In the midafternoon.

Question 16

What topography factors affect wildfires?

Answer 16

1. Elevation
2. Position on slope
3. Aspect
4. Shape of landscape
5. Steepness of slope

Question 17

Fuel on the _______ facing slopes are usually drier and burn more easily.

Answer 17

South.

Question 18

What fuel factors influence wildfires?

Answer 18

1. Size and shape
2. Moisture content
3. Horizontal continuity
4. Vertical continuity
5. Chemical content

Question 19

[True/False] Large woody material burns more easily than pine needles.

Answer 19

False.

Question 20

What is a ground fire?

Answer 20

A fire that creeps along under the ground surface - little flaming, more smoldering.

Question 21

What is a surface fire?

Answer 21

A fire that moves along the surface - burns slowly with smoldering, limited flaming.

Question 22

What is a crown fire?

Answer 22

Flames are carried along tree canopies - driven by strong winds and steep slopes.

Question 23

How do fires affect erosion?

Answer 23

Fires remove anchoring vegetation on steep slopes, leading to more erosion and landslides.

Question 24

What are the atmospheric effects of a wildfire?

Answer 24

Fires contribute to smog formation, as well as the release of smoke, soot, and gases.

Question 25

How are wildfires related to climate change?

Answer 25

Climate change increases the intensity and frequency of fires.

Question 26

What is an example of vegetation that benefits from wildfire?

Answer 26

Bearberry uses fire to propagate - the seeds need heat from the fire to open.

Question 27

What are some benefits of wildfires to plants and animals?

Answer 27

1. Removal of surface litter for grasses 2. Recycles nutrients in the system 3. Animals benefit from increased plant life.

Question 28

How can the hazards of wildfires be reduced?

Answer 28

Enforce building codes, ban burning and fireworks, prescribed burns, insurance, evacuation.