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Wildland Fire Science School - Part 1: Fire Basics

By Educational Resources

This unit consists of three lessons where students will learn or review what fire is and how it spreads. They will explore the three requirements needed to start and maintain a fire (the Fire Triangle), as well as the three factors that affect wildland fires (the Fire Behavior Triangle).

Return to Wildland Fire Science School

Part 1: Fire Basics

Lesson: Burning to Learn

Grades: 6-12

Length: Lesson 1: 1-2 class periods (50 minutes each), Lesson 2: 3 class periods (50 minutes each) 

Topics

  • Fire Basics 
  • What ecosystem do I live in and is this ecosystem prone to wildfires? 
  • Why do things burn? What does fire need to start and be maintained? 
  • How do things burn? 

Materials Needed: See lab handouts and teacher guides for suggested lab materials. Computer access for internet research.

NGSS Alignment: 

  • Disciplinary Core Ideas: 
    • ESS3.C: Human Impacts on Earth Systems
      • The sustainability of human societies and the biodiversity that supports them requires responsible management of natural resources. (HS-ESS3-3) 
    • PS3.A: Definitions of Energy  

      • At the macroscopic scale, energy manifests itself in multiple ways, such as in motion, sound, light, and thermal energy. (HSPS3-2) (HS-PS3-3) 

    • PS3.B: Conservation of Energy and Energy Transfer 

      • Energy cannot be created or destroyed, but it can be transported from one place to another and transferred between systems. (HS-PS3-1),(HS-PS3-4) 

    • PS3.D: Energy in Chemical Processes  

      • Although energy cannot be destroyed, it can be converted to less useful forms—for example, to thermal energy in the surrounding environment. (HS-PS3-3),(HS-PS3-4)  

  • Science and Engineering Practices: 

    • Asking Questions and Defining Problems 

    • Developing and Using Models 

    • Planning and Carrying Out Investigations 

    • Analyzing and Interpreting Data 

    • Engaging in argument from evidence 

    • Obtaining, Evaluating, and Communicating Information 

  • Crosscutting Concepts

    • Cause and Effect 

    • Systems and System Models 

    • Energy and Matter 

Overview:

This lesson serves as an introduction to the basics of fire and wildfire. Students will learn or review what fire is and how it spreads. They will explore the three requirements needed to start and maintain a fire (the Fire Triangle), as well as the three factors that affect wildland fires (the Fire Behavior Triangle). 

  • Lesson 1: Is fire a part of my ecosystem(s)? 
  • Lesson 2: Introduction to Fire Triangles  
  • Lesson 3: Wildfire Behavior Labs 

Vocabulary:

  • Fire 
  • Fuel 
  • Topography

Teacher Background:

What is fire?

Fire is the manifestation (light and heat) of a chemical reaction (combustion) between oxygen and fuel. The fuel and oxygen must be at or above ignition temperature for the chemical reaction to occur, and a catalyst is required to ignite the fire. Scientists created the Fire Triangle graphic to demonstrate that these three things are needed to ignite fire. Without any one of the three legs of the triangle (oxygen, fuel, heat), a fire cannot be sustained. 

The flames of fire contain burning fuel and a variety of gases, including water vapor being released from the fuel, carbon dioxide, carbon monoxide, smoke, and others. This means it is composed of matter. The heat and light released by the flame is energy.  

Fire changes the nature of the fuel. 

Fire Behavior

Wildfire behavior is complex and depends on three factors: vegetation, weather, and topography . There is also a triangle graphic to show the importance of these three components of wildland fire, with one leg of the triangle devoted to each of those three factors.  

Fire can be beneficial or destructive or both. We will explore these aspects in later lessons. 

Common Misconceptions About Fire

The following common misconceptions are all untrue. As you work through the lessons with your students, you may want to help them identify and correct any of these misconceptions, many of which are not directly addressed in the lessons. 

  • Metals, minerals, and possibly other very hard things do not easily burn at wildland fire temperatures. 

  • Fire is a gas 

  • Lighting a match is necessary to start a fire 

  • Bigger fires are hotter 

  • Water extinguishes fire because it neutralizes the flames 

  • Water extinguishes fire because it transforms fire into smoke 

  • Friction is necessary to start a wood fire 

  • Smoke is part of the fire cycle 

  • Fire is made of matter 

  • Black smoke indicates that the fire more intense than white smoke 

  • Embers are hotter than fire 

  • Smoke contains oxygen 

Goals/Objectives:

  • Explain what fire is in terms of matter and energy. 
  • Define the requirements needed for fire to start, grow, and be maintained. 
  • Compare and contrast the roles of oxygen and carbon dioxide in fire. 
  • Explain or demonstrate the three factors that affect the behavior of a wildland fire. 
  • List examples of benefits and harms of fire to humans and/or ecosystems. 

 

Lesson 1: Is wildland fire a part of my ecosystem?

Engage

Students will need to understand the ecosystem(s) in which they live and attend school throughout this set of fire lessons, so it is advisable to start with a short lesson on identifying and defining their ecosystem(s). For urban environments where ecosystem type may be more challenging to determine, choose a nearby or popular ecosystem of the students’ choice. Make sure that students understand the difference between weather and climate before heading outside for a walk. Take students on a walk around the school grounds or have them do this with an adult as homework. Ask them to make observations and answer the questions below. Note: For students in urban areas, the class can walk in a nearby park or nature area, if accessible. Alternatively, teachers in urban areas may wish to skip to the Explore/Engage step.  

Observations: As you explore your home or school neighborhood, record your observations 

  1. What evidence of nature do you see? For example, trees, grass, shrubs, small flowering plants, small animals, larger animals. 

  1. What is the weather today? Is the weather cold, mild, or hot? Is there any precipitation or wind? 

  1. What season is it right now? 

  1. What you think the climate (long-term weather by season) is like in this area. For example, explain your summers and winters (mild? severe? wet? dry?). Do the plants you see require a lot of water or very little water? Is that natural? If you are in an urban area with a lot of plantings made by humans, do you think they have to be watered often rather than being adapted to the natural amount of rainfall or moisture? 

  1. Do you think that fires are a natural part of this ecosystem? Explain your reasoning. Note that you do not have to be correct – this question is designed for you to hypothesize about the nature of the ecosystems in which you live and/or attend school. 

  1. What is your current latitude and longitude? 

  1. What are the major features of the ecosystem where you are located? Be sure to include moisture, climate, and vegetation) 

  1. In what specific ecosystem type(s) are you located? 

 

Explore/Explain

  1. Back in the classroom, have students research and discover the ecosystem(s) in which they live or attend school. Several potential sites and maps are:
  2. Students share their findings, either in small groups or as a class. Small group work could lead to discussions about how the students perceive their ecosystem(s) and surroundings. From this, if time allows, student groups could build a strong definition of their ecosystem(s).

 

Lesson 2 – Fire Basics

Engage

There are several options for sparking students’ interest in learning about fire. How you start may depend on your students and community. If students’ lives or homes have been threatened by fire, or if you anticipate an emotional reaction to fire, you may not want to start with a dramatic video.

  1. Journal or sketching activity: Draw or sketch fire. How has fire helped you? How has fire hurt you? What is fire? Multimedia is fine, and a mixture of writing and art is likely to engage more students.

  2. Show fire video/s and find a short, dramatic video of a wildland fire to initiate a discussion about fire.

  3. Using one of the options above to discuss the questions below. Have students record their answers to keep track of both incorrect and correct responses.

    • What is fire?

    • What seems like fire but is not?

    • What ways do humans use fire?

    • What are some causes of fire?

    • What does fire need to start?

    • What does fire need to keep going?

 

Explore

What is the Fire Triangle?

IMPORTANT: The middle (or a fourth element) is the chemical reaction that occurs between the three; without this, fire will not happen. In fact, fire needs all four of these elements – removing one of the legs kills the fire. 

Show students an image of the Fire Triangle and explain that all three legs of the triangle (fuel, heat, and oxygen) are required for a fire to be sustained. Without any one of these, a fire will go out. Ask students to list any sources of these three legs they can think of. This can be done individually, in small groups, or as a class. There are numerous sites with information about the Fire Triangle, so if you prefer, you can have students research the Fire Triangle and share their findings. One possible site is this one from the National Park Service.

 

Explain

Student research & reading: Ask students to navigate to the USGS Wildland Fire Science website. Give them 10-15 minutes to explore, searching for topics of interest to them. If teachers plan to continue with the subsequent Fire Impact and Fire Ecology lessons, this could be a single class period activity in which students take notes on their research. Students then share interesting findings.  

If teachers will not be continuing with the fire lessons, this could be a multi-class period activity in which students answer specific questions with their research and prepare a product, such as an oral report, a slideshow, one-pager, or short research paper. Alternatively, students could focus their research on their local ecosystem and its relationship to fire. 

Potential guiding questions for students: 

  • What topics on the Wildland Fire Science site interest you most? 

  • What about these topics do you find interesting? 

  • Explain three to five things you learned from your research. 

If students research a particular area rather than wildland fire topic, have them report on: 

  • Habitat type 

  • Types of fuel in that habitat 

  • Prevalence of fire 

  • Factors involved in the fire prevalence 

Additional Websites for Research

National Fire Situational Awareness (nwcg.gov) - interactive, real-time fire map that allows users to measure fires, see where different types of actions are occurring, and examine data on specific fires.   

U.S. Government Accountability Office – Wildland Fire Management issues 

National Interagency Fire Center (NIFC) – the NIFC is a collaborative effort across government land management agencies. Participants include U.S. Forest Service, Bureau of Land Management, National Park Service, U.S. Fish and Wildlife Service, and the Bureau of Indian Affairs. 

 

Elaborate

Wildland Fire Behavior

What factors affect fire behavior and how can we test these factors? 

We know from the Fire Triangle what a fire needs to burn. How can we determine where fires will burn? Think about two different ecosystems. Which one is more likely to burn? For example, let’s look at the Sonoran Desert in the southwestern United States. How likely is it to burn? Does it have heat, oxygen, and fuel? The answer is yes, but fuel is less abundant than in a forest. Fire can also occur in deserts, but may be less severe due to a lower amount of available fuel. The Fire Behavior Triangle shows the features that determine a wildfire’s behavior: topography of the land, weather, and fuels. Fuel appears in the basic Fire Triangle as well; here it refers to the types of fuels as a determinant of fire behavior. 

Fire Ecosystem Card Activity 

The purpose of this activity is to have students think about the two fire triangles and apply what they have learned to determine how different ecosystems may burn. 

Print the fire ecosystem cards. These can be cut and laminated, or just cut and passed out. Give each small group two to four photographs and ask them to think about which of the three legs of each triangle they can find. Have them try to order their photos or cards in order of least to most flammable, or likely to burn. Be sure to have them back up their ideas with strong reasoning. Have them share their hypotheses with the class.  

 

Lesson 3 - Wildfire Behavior Lab

This laboratory experiment should only be conducted if safe testing areas are available and if the school’s safety official has agreed to the methods. Students brainstorm methods to test each of the three legs of the fire triangle. 

  • Weather – fan (wind), spray bottle (rain); 

  • Topography – slope, breaks in the vegetation; 

  • Fuels – wet wood, dry wood, wet leaf litter, dry leaf litter, metals, other non-toxic possibilities that may or may not burn. 

 

Evaluate

 Evaluation for this lesson can come from a variety of student products:  

  1. Lab write-ups;  

  2. One-pager demonstrating what they learned from the Burn to Learn activity;  

  3. Presentation of research and lab findings with small group or individual presentations -- slides, videos, or other preferred method.

 

Extend

Outdoor laboratory experiment in which students try to create a fire using natural materials. Only to be conducted in a safe situation to work with fire outdoors.  

Important notes: 

  1. Teachers will need to check with district safety officers about how and where to set this up experiment. 
  2. Teachers could use engineering design process for this. 
  3. Small groups brainstorm a solution to the question, “How can we create a fire outside safely and with natural materials?” Students try their solutions, recording in detail their methods and results. 
  4. Students share out and make an all-class list of what worked and what needs to be changed.   
  5. Additional lesson plans are available from the U.S. Forest Service, Rocky Mountain Research Station.

Teacher Instructions for Hands-on Fire Experiment 

Procedure 

Divide students into small groups and ask them to record everything they think is necessary to start and maintain a fire. An optional activity can be used with either the student inquiry or the directed-lab option. 

Suggestions for Student Inquiry Option 

Ask small groups to present their ideas to the class. Have students write responses on sticky notes and place in a central area. If students use sticky notes, ask them to sort the ideas into any categories they see. Lead a class discussion about the elements of fire. If they are not coming up with fuel, oxygen, and heat as the main elements, you can introduce the Fire Triangle if you have not already done so. Ask students to create hypotheses about these categories and whether fire can be started and maintained with or without them. 

Provide a list or physical examples of possible materials they can use for their lab. Ask them to write a plan to test their hypotheses. Depending on prior student knowledge, teachers may need to scaffold or give hints about certain aspects, such as ways to extinguish fire. The plan should include: 

  • Hypotheses or research questions to be tested 

  • Materials list 

  • Quantity of each material needed 

  • Detailed procedure 

  • Safety plan explaining all the ways in which they will undertake their experiments with all possible safety precautions. These should include standard lab safety behavior, such as long hair pulled back, safety goggles, flame-resistant gloves, sleeves pulled back, water and fire extinguisher present. 

Once the experiments are approved, monitor students as they set up and conduct their experiments, then have them complete the lab report. Optional questions are provided.