Fire Management

Overview

In this lesson, we will learn about how humans have influenced fire behavior through their management of the environment and fighting fire.  We will consider how our fire management has shifted throughout history and how different people relate to fire.  Students will perform an activity to better understand how historical and modern fire management influences fire regimes.

Learning Outcomes

Students will know the following:

• Thinning forest biomass improves resilience to wildfire
• How different peoples and cultures have used fire as part of a suite of landscape management practices with varying ecological effects
• The U.S. Forest Service started a policy of fire suppression following the Great Fire of 1910

Students will understand the following:

• Fire suppression results in more severe fires in the long term

Students will be able to do the following:

• Create bar charts to display experimental data

Essential Questions

• How have fire regimes changed over time and why?

• How have humans used fire in the past and today?
• How has human influence on fire regimes altered the ecology of Southwestern forests?

NextGen Science Standards

• MS-LS2-1 Ecosystems: Interactions, Energy, and Dynamics
  • Analyze and interpret data to provide evidence for the effects of resource availability on organisms and populations of organisms in an ecosystem.
• MS-LS2-2 Ecosystems: Interactions, Energy, and Dynamics
  • Construct an explanation that predicts patterns of interactions among organisms across multiple ecosystems.
• MS-LS2-3 Ecosystems: Interactions, Energy, and Dynamics
  • Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.
• MS-LS2-4 Ecosystems: Interactions, Energy, and Dynamics
  • Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
• MS-ESS3-3 Earth and Human Activity
  • Apply scientific principles to design a method for monitoring and minimizing a human impact on the environment.

Materials

• 2 12” x 12” baking sheets
• 2 12” x 12” ceiling tiles
• 8 2” bolts
• 8 nuts
• 3 6” angle irons
• 2 pieces of 100% cotton letter paper
• 2 12” x 12” pieces of pegboard
• 2 12” x 12” sections of 1” wire mesh
• 21 toothpicks
• 21 paper drink umbrellas
• 2 matches
• Damp cloth
• Grill
• Stopwatch
• Fire extinguisher

Glossary

• Acequia: A traditionally-managed water canal or ditch used for irrigation and the associated political organizations that determine its management
• Ecological management: Actions used to protect ecosystems to ensure natural resources moving forward
• Fire dependent: A species or ecosystem that requires fire for its reproduction or survival
• Fire suppression: A management policy that aims to control and extinguish wildfires as quickly as possible
• Firebreaks: A gap in fuels, commonly vegetation, to prevent wildfires from spreading
• Landscape: An area of land and how the natural and human elements interact within it
• Patchwork mosaic: A landscape with different ecosystems or ecosystem structures in various areas
• Prescribed burning: A fire that is intentionally set for specific purposes
• Rainfed agriculture: Agriculture that does not involve irrigation; watering comes from rain
• Settler colonialism: Taking over land and extracting resources to a different location by sending settlers who permanently form communities that displace indigenous peoples and their ecological management
• Three Sisters: Traditional agriculture that involves corn, squash, and beans, which help each other grow more productively because of their ecological functions
• Traditional ecological knowledge: The knowledge, management, and spiritual practices indigenous and local peoples have of their environment
• Weeks Act: Legislation allowing the federal government to purchase land to protect the headwaters of rivers and watersheds for conservation and fire protection purposes

Activating Strategy

Time: 5 minutes

Have students watch the Collaborative Forest Restoration video from PBS-NM Our Land: New Mexico’s Environmental Past, Present, and Future: https://www.pbs.org/video/collaborative-forest-restoration-l3m5tv/

Learning Approaches

Time: 45 minutes

Humans have had a profound impact on fire’s role in ecosystems, both in how we manage ecosystems and our direct management of fire.  Let’s explore how this has changed over time and how it might adapt moving forward.

The indigenous peoples of the Southwest, such as the Pueblo, Navajo, Apache, and other tribes, have a long history of using and managing fire as an integral part of their cultural practices and land management strategies. As a result, fire played a significant role in shaping the landscape and maintaining the ecological balance in the region for millennia.

Indigenous communities in the Southwest practiced intentional prescribed burning for various reasons:

• They used fire to clear land for agriculture. Burning removed vegetation, eliminated pests, and enriched the soil with nutrients, creating fertile grounds for cultivation of diverse crops, including the Three Sisters: corn, squash, and beans.
• They also burned forest to create clearings with grasses that would attract wildlife for hunting. These clearings also created a patchwork mosaic of different habitat types, increasing the diversity across the landscape. They used a similar approach in grasslands, where fire maintained open grassy areas that supported wildlife populations of elk, deer, antelope, and bison.
• In addition to providing indigenous communities with food, traditional fire management practices, such as prescribed burns, helped prevent the build-up of dense vegetation, suppressing fuels, which, in turn, reduced the intensity and spread of damaging wildfires.
• Finally, fire was an integral part of religious ceremonies, initiations, and other cultural practices, symbolizing renewal, purification, and spiritual connection with the land.

Collectively, the knowledge, ecological management, and beliefs indigenous peoples had regarding fire reflect a profound understanding of the local environment passed on from generation to generation to ensure sustainable and balanced relationships with the places they lived.

The colonization of the region and the imposition of Spanish settlements disrupted indigenous fire management practices beginning with Francisco Vázquez de Coronado’s and Juan de Oñate’s expeditions in the 1500s.  Hispano settler-colonial communities borrowed and altered indigenous fire-related knowledge and management to reflect their different relationship to the land.

Similar to indigenous practices, Hispano communities used fire to clear fields and prepare the land for agriculture, eliminating potential pests and disease while enriching the soil with ashes and char.  However, unlike indigenous agriculture, which was traditionally rain-fed, Hispano communities utilized fire along irrigation ditches, known as acequias, to clear vegetation and maintain the flow of water. Controlled burns were conducted to remove brush and debris that could obstruct the flow of water, ensuring effective irrigation for their forms of agriculture and orchards.  Hispanos also practiced controlled burning to manage rangelands and promote the growth of plants that were good for grazing animals, but unlike indigenous communities, the Spanish did so for raising livestock, like sheep and cows.  They also constructed firebreaks to protect their communities, fields, and other important resources from uncontrolled fires.

Fire management underwent another huge change after the annexation of what is now New Mexico by the United States following the Mexican-American War in 1848.  Much of the land transferred hands from Hispano communities to wealthy timber and sheep barons, who exploited the natural resources the land provided and then sold it to the U.S. government.  Ultimately, much of the land is now owned and managed by federal government agencies, including the Forest Service and Bureau of Land Management.  In the 19^th and 20^th centuries, they implemented land management policies focused on fire suppression.

Several factors informed fire suppression in land management in the Southwest.  In the late 1800s, the U.S. government established forest reserves, including the Gila Forest Reserve in New Mexico. These reserves were managed with a focus on timber production, so fire suppression aimed to prevent the risks fires posed to forest resources, such as timber and food for livestock.  It also helped protect the railroads in the region. In the early 1900s, Congress passed the Weeks Act, which led to the creation of national forests, including the Carson and Santa Fe National Forests in New Mexico. The newly formed U.S. Forest Service assumed responsibility for managing these forests.  Following the Great Fire of 1910, which burned 3 million acres in Montana and Idaho and killed 85 people, the Forest Service adopted a strict fire suppression doctrine.  This approach advocated for the immediate and total suppression of all wildfires, regardless of their ecological role or natural occurrence. Their “10 a.m. rule” required putting out every single wildfire by 10 a.m. the day after it was discovered. Reflecting a perception that fire was inherently destructive and needed to be extinguished at all costs, it functionally eliminated fires from the landscape.  In the 1940s, they released the iconic character Smokey Bear character to instill the message of personal responsibility: “only you can prevent forest fires,” further reinforcing the idea that all fires were harmful and should be suppressed.

This policy dominated land management in the western United States for the remainder of the 1900s.  Despite the intentions, the suppression of fires in New Mexico and across the United States had unintended ecological consequences. Fire-dependent forests became overgrown and susceptible to catastrophic wildfires as fuels accumulated. The absence of natural fires also limited populations of certain fire-dependent species like aspen, altered the composition and structure of ecosystems, and disrupted soil fertility, which depended on fire to release nutrients.

In recent decades, however, there has been a growing recognition of the ecological role of fire and the need to reintegrate fire into land management practices. Prescribed burns are part of a complex set of land management practices we are using to address a century’s-worth of mismanagement and fire suppression.  A first step is often thinning biomass to limit the amount of standing fuel so the fire does not spread into the canopy.  The thinned biomass, called slash, can be spread evenly on the ground or piled and then burned during an appropriate weather window (no wind, high humidity) under the supervision of fire crews.  Land managers are also allowing some naturally occurring fires to burn where they are likely to be ecologically beneficial without threatening human communities.

These new fire management policies also aim to incorporate and acknowledge traditional knowledge and practices into land management strategies.  They aim to strike a balance between fire suppression and the restoration of natural fire regimes in New Mexico and beyond.

Now that you know about the history of fire management in New Mexico, let’s do an activity to show how fire suppression results in higher wildfire severity.  Which of the following models of forest management do you think will result in higher burn severity?

• Divide students into two groups
• Have one group arrange the fuels representing historic fire conditions and the other arrange the fuels for representing modern forest fuel loads
  1. Place a ceiling tile into each of the baking sheets
  2. Thread a bolt through the corners of each pegboard piece and fasten it with the nut to create a platform
  3. Place this pegboard onto the ceiling tile
  4. Place the paper on the center of the pegboard
  5. Stick toothpicks through the appropriate holes in the pegboard where the matches and umbrellas are supposed to be, so they stand embedded in the ceiling tile
     1. The historic conditions group should place 6 toothpicks
     2. The modern conditions group should place 15 toothpicks
  6. Gently lift the paper to place angle irons beneath
  7. Place the wire mesh over the paper, keeping the toothpicks standing
  8. Replace the toothpicks with drink umbrellas; these represent trees
• Have students hypothesize about the fire behavior for both scenarios
• Place the models, one at a time, starting with the historic fire model, in a grill or other fire-proof location
• Light the edge of the paper near them to simulate lightning strike and start a stopwatch
• Record the duration of the burn and count the number of trees that burned
• Wet down the simulation with a damp towel
• Repeat this exercise with the current fire model
• Have students calculate the percentage of “trees” that died in each simulation, recording the burn time and percent mortality in Table 2 below.

Table 2: Burn experiment data

• Have students graph the data in Table 2 as bar charts. Make sure they label their axes!

Summarizing Strategy

Time: 5 minutes

Have alternate students list one way we can manage fire sustainably and one that results in unsustainable management (i.e., one up, one down).  List these on the board as the students articulate them.

Assessing Strategy

• Correctly calculate percentage of trees killed
• Graphs should accurately depict experimental data
• Graphs axes should be labeled and include units, where applicable