Wildland fires have been a part of the Rocky Mountain ecosystems for millions of years, resulting from lightning strikes, volcanic eruptions, and spontaneous combustion. The plants and animals evolved to survive after those fires.
When humans arrived, ignitions were accidental and, in some cases, intentional. Human-caused ignitions include arson, accidental ignition, cigarettes, mechanical equipment, and fireworks. The use of fire in land-clearing and agriculture by native Americans, ranchers and farmers also started uncontrolled wildland fires.
Fires are an important part of nearly every ecosystem. They help clear out dead plant matter, which stimulates nutrient-rich growth. The survival and reproduction of species adapted to fire are important.
In more recent times, humans have gone all out to suppress fires. Special teams of firefighters use all kinds of tools, including aircraft, to bring fires under control. Fire season used to be during the summer, but because of climate change, fire seasons are getting longer. Parts of the Western United States now have fire seasons that are more than a month longer than they were 35 years ago. In addition, the fires are getting bigger and more difficult to control. The names of wildland fires are usually based on nearby geographic features like mountains or bodies of water close to the ignition point.
On Dec. 30, 2021, a grassland wildfire in Boulder County erupted into a suburban firestorm called the Marshall Fire. That fire destroyed 1,084 homes and seven commercial properties in the towns of Louisville and Superior. It was the costliest wildfire in Colorado history.
The East Troublesome Fire that ignited in the Arapaho National Forest in Grand County on Oct. 14, 2020, grew into the state's second-largest wildfire in history. It destroyed 555 structures in Grand and Larimer counties, killed two people and burned into the West Side of Rocky Mountain National Park. It burned across the Continental Divide and into Beaver Meadows on the East Side of the Park.
The Cameron Peak Fire, which ignited on Aug. 13, 2020, began near Walden, north of Rocky Mountain National Park. It became the largest wildfire in Colorado history and destroyed 469 structures, including 42 primary residences.
These three fires became a wake-up call about the severity and explosiveness of wildfire in Colorado in a new era of global warming. Even with satellites to detect and track them and aircraft to fight them, humans often cannot control them.
Another issue with wildfire is the amount of carbon dioxide that is released into the environment. In some areas, more CO2 was released in wildfires than was produced by all the fossil fuels the cities and towns in the area. This is becoming a concern for climate goals. Forests are generally considered a carbon sink, but are now becoming a carbon source.
Wildfires are an advantage in some situations. They can burn dense vegetation and reveal archaeological sites, prehistoric artifacts, structures, and rock art. Six hundred eighty-two archeological sites were discovered after wildfires in Mesa Verde National Park.
Some wildfires are intentionally set by foresters to clear out old growth and create an open area that will block future wildfires from moving. So what happens to an ecosystem after the fire? Over the 385 million years that forests have existed in North America, the plants and animals have evolved to survive or replenish the areas that seem to have been destroyed by fire.
The lodgepole pine is common throughout Colorado. These pines produce serotinous cones, which remain sealed with resin. During a fire, the resin melts and the seeds are released. They do not often open under normal conditions, but the severe heat of a fire unseals them and scatters the seeds into the nutrient-rich ash. A year after the fire, large numbers of trees begin to grow, and in some cases, so close together that the area is called a dog hair stand. Walking through the trees is like being a flea in the hair on the back of a dog. These trees have evolved to replenish the forest.
Some fire-resistant trees, like ponderosa pines, are self-pruning so that there are no branches close to the ground that may catch fire when only the grass is burning. They also have thick bark and deep roots to help survive fires. The sap in some trees seals the cracks inthe bark to make them more fire-resistant. Some hardwood trees such as Ponderosa pines, Western larch, Douglas fir, Coast live oak, and giant sequoias, have evolved with these characteristics. Many individual trees may survive in areas where a lot of trees are destroyed.
Some trees, like Aspen, have high moisture content that makes them less likely to ignite. In addition, many deciduous trees, like Aspen, have roots that clone new trees after a fire. Shrubs and many flowering plants also have adaptations to survive fire. Penstemons, fireweed, potentillas, coneflowers, black-eyed Susans, thistles, and many others are called pyrophytes, since their seeds will often survive a fire. They will frequently grow and bloom in large quantities after a fire.
Fire leaves behind ash, rich in nutrients for new plants to sprout and grow rapidly. Fire is a reset of an ecosystem. Wildfires disturb landscapes, clear out old growth, and leave behind a patchwork of habitats that promote biodiversity.
Animals are also impacted by wildfires. Large animals, such as deer and elk, may instinctively move to safer areas of a forest that are not impacted by the fire. Those who are not old or really young can move or run away from wildfires. They may also seek refuge in bodies of water like ponds, lakes, and streams.
In some cases, animals may move back into burned areas, which can be safer than the advancing fire front. Animals like porcupines, tree squirrels, and pine martens live in the trees and may get trapped and not survive. Small ground-dwelling animals like ground squirrels, marmots, and reptiles may seek shelter underground in burrows, in logs, rocks, or moving water.
Birds have mobile options and can easily flee long distances. Animals that flee fires may travel into unfamiliar or developed areas, where they compete with existing wildlife or face issues with human interactions. The loss of habitat is also a food and shelter loss that can be the most significant threat to those animals. Some animals may survive the fire only to suffer from health issues, such as smoke inhalation and a weakened immune system.
Deer and elk often move into the fire-burned areas in the following spring because there is an abundance of succulent grasses and shrubs to exploit. There are still hazards there, however. Rain can cause dangerous mudslides and contaminate the water with ash. Dead, falling trees can be a danger and trees on the ground can be significant obstacles.
Forests impacted by fire do not recover significantly in a human lifetime, but over hundreds of years, it may not be obvious that there was a fire. There is evidence to look for. I have not wandered through any forested area of Colorado where I did not find evidence of fire. Charcoal on the ground and "cat eyes" on trees are a giveaway. Cat eyes are triangular shapes in the bark at the base of trees that were burned in a fire.
Settlers moving into Colorado in the 1800s reported frequent fires in the mountains. Some of those fires were intentionally set by Native Americans and the settlers to open the landscape for hunting and farming. Their reports of fire did not describe fires as large and severe as those we face today. In the past 50-100 years, fire was considered to be a bad thing, and people went to extremes to prevent or put out those fires. That resulted in large swaths of mature forests that today can develop into the massive, intense fires we experience today.
Chief Seattle said, "Humankind has not woven the web of life. We are but one thread within it. Whatever we do to the web, we do to ourselves. All things are bound together. All things connect."
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