Every year we hear of forest fires that engulf cities, endanger human lives, and cause the mass destruction of property. These fires rage uncontrolled, so large that they cannot be put out, turning the skies red and charring everything in their paths. Forestry and fire services take many precautions to avoid these blazes. People visiting forests are told to be careful with their use of fire, with some national parks banning the lighting of fires altogether. In addition to this, large areas of forest are often cleared to prevent future fires from spreading. Water bombers—special planes used for dropping water on active fires—are kept ready to respond at a moment’s notice. Fires are seen by most as a menace—a danger to forests and people alike. But are forest fires really as bad as we think they are?
Fires have increased in frequency, with the United States witnessing a threefold increase in the last two decades alone! Human activity, both intentional and accidental, has made ignitions in “forested” areas far more common. Nearly 85% of wildfires from 2000-2017 in the U.S. were anthropogenic (caused by humans). Owing to climate change, as well as the ways we use land, fires have also been increasing in size and intensity. Extreme fires now occur a lot more often than they once did.
Emitting a large quantity of greenhouse gases, causing considerable air pollution and billions of dollars in damages to property, it would seem that wildfires cause more harm than good. Why else would we spend so much time and money trying to stop them?
But is there more to the story? To answer this question, we have to don our evolution-lenses to take a closer peek at wildfires and the places where they burn.
Fires, Regimes and Ecosystems
Wildfires have been around since plants have been on land. Fossil evidence of fires—called fusain—has been found from the Devonian, more than 400 million years ago. Land plants and fires have coexisted for a long, long time, long enough for plants to evolve to cope with periodic burning, and even use wildfires to their benefit.
Wildfires in different places burn differently. Some regions burn intensely but infrequently, or might even have fires that burn below the ground. Other regions might encounter milder wildfires more frequently. Yet others might have fires that burn all the way up to the canopies of tall trees. Factors like the frequency, intensity, and location (above or below ground), and the plants that get burnt, change the ways in which fires burn. These factors, along with the way fires burn, are that region’s fire regime. Think of a fire regime as a specialized way of life for the plants of a region, one that depends on the occurrence of fires in a specific way.
Thus, plants have learned how to live with wildfires, and often can dictate the way in which fires burn. Fires, in turn, make plants adapt to their presence, and modify the ecosystem. This means that fire regimes are controlled by complex relationships between plants and fire.
An example of this dynamic are the longleaf pines found in the Southeastern USA. In the 1920s, a forester named H. H. Chapman theorised that longleaf pines require periodic fires to survive. These pines are outcompeted by other hardwood species found in the area, and commonly suffer from a disease caused by a fungus. Longleaf pines have a hard time establishing themselves in forests amongst other plants. They grow rapidly to the height of a few inches, and then sprout a ring of fire-resistant pine needles. They then stop growing for a few years, sending a large network of roots underground, waiting for the opportune moment. When a fire strikes the forest, the competing plants burn. Pine needles suffering from the fungal disease also get burnt off. The longleaf pine jumps into action, rapidly reaching for the skies. It soon grows big enough to withstand any but the largest of fires. Some pines even retain their dead branches to act as fuel for fires, using their higher flammability to kill their competing neighbors.
Serotiny is a phenomenon where plants such as the sequoia, cypress and eucalyptus delay the dropping of their seeds until the passage of a wildfire through their surroundings. Upon the arrival of a fire, the adhesive wax holding the seeds within melts, causing the trees to release seeds from their canopies. Serotiny effectively protects the seeds from the ravages of the fire and other hazards present on the forest floor, and presents them with an ashy, nutrient rich medium for germination once they drop.
Other plants, such as Terminalia elliptica, the crocodile-bark tree, so called for its likeness to the scales of a croc, have thick, spongy barks. These barks, acting like fireproof jackets worn by firefighters protect the rest of the tree inside from temperatures nearing 800 degrees celsius! (over 1400 degrees fahrenheit!)
Many grasslands and savannas around the globe depend on fires for their existence. The climates and soils that host these grasslands would also support woody plants. Furthermore, woody plants prevent grasses from growing by taking all the sunlight and leaving grasses in shade. Why, then, do these areas host grasslands instead of forests? Fire!
The fire regimes of a savanna (left) are very different from that of a forest (right)
Grasses are used to regimes where there are regular, large burns. They grow during the rainy season, building up large amounts of fuel, and then dry rapidly as the weather gets warmer, providing the perfect conditions for wildfires to run free across the surface of the ground. A majority of the biomass of grasses, however, is stored underground, safe from being scorched in the infernos to come.
Saplings of woody plants, however, don’t do very well in these frequent fires. Unable to grow significant amounts in the short time they have between burns, these saplings cannot escape the fire trap—the height above ground encompassed by the flames of these grass-fuelled fires. Saplings of woody plants thus get killed in the blaze. Woody tree species only stand a chance in these landscapes when there are periods when fires are delayed—when the saplings that survive manage to grow taller than the fire trap. This limits the number of woody plants, and so forests are stopped from invading the grasses’ turf (pun intended).
Humans, flora and flames: Where to burn, when to burn
There’s just one big problem that fire-controlled environments face. For centuries, many forest-dwelling communities of people used wildfires as a tool to manage forests. The fires they set ablaze largely mimicked the fire regimes of natural ecosystems. Slash and burn or swidden agriculture, for example, involved the careful choosing and burning of a patch of land. The burning cleared the land for agriculture. Crops were then grown in these patches for a few years and abandoned afterwards. The clearings left in the forest were soon reclaimed by nature, until the farmers returned. This repeating cycle allowed nutrients to return to the soil. More importantly, it gave saplings the chance to grow in unobstructed sunlight, helping the next generation of plants.
Controlled burns were also used to reduce the intensity of fires. Using up accumulated fuel on a regular schedule pre-empted the occurrence of extreme burns. These prescribed burns are still used by many forest services for the same reason
But now, climate change and human activity are altering fire regimes across the planet. Large patches of forest are being lost to extreme fires, turning them into scrub jungle and grasslands. Meanwhile, grasslands that are prevented from burning are being taken over by woody species, and converted into forests. Such biome switches are not easily undone, and lead to the loss of many species.
From fires in the Amazon rainforest, to bushfires in Australia, wildfires have gone from being a force of life to one of extermination. Fire, like many other things, is best in moderation. And the laws of nature and evolution know just the right amount for the right places. Perhaps this is a strange case where, to save the world’s wilderness, one has to first let it burn (the way it should).
Glossary
Anthropogenic: Arising from the activity of humans
Fusain: Bits of charcoal that have been fossilized
Fire regime: The pattern, frequency, intensity, and nature of the fire burning in a particular ecosystem
Biomass: The amount of organic material that comes from plants or animals
Fire trap: (In this context) The zone (height off the ground) that would be within the flames of a fire
Prescribed burns: Wildfires that are intentionally lit to reduce the risk of larger, uncontrolled fires
Scrub jungle: Ecosystems dominated by shrubs and herbs, as opposed to forests that have taller trees
Flesch Kincaid Reading Grade: 8.2
Flesch Kincaid Reading Ease: 64.2
References
The ecology of fire, Nature Scitable
https://www.nature.com/scitable/knowledge/library/the-ecology-of-fire-13259892/
The ecology of Fire, C.F. Cooper
Fire Effects on the Environment, USFS Pacific Northwest Research Station
https://www.fs.usda.gov/pnw/page/fire-effects-environment
The Impact of Forest Fire on Forest Biodiversity in the Indian Himalayas (Uttaranchal), Amit Parasher, Sas Biswas
https://www.fao.org/3/XII/0358-B1.htm
Fire as a global ‘herbivore’: the ecology and evolution of flammable ecosystems
https://www.sciencedirect.com/science/article/abs/pii/S0169534705001321
Wildfire Causes and Evaluations
https://www.nps.gov/articles/wildfire-causes-and-evaluation.htm
How Much Do Wildfires Cost in Terms of Property Damage?
https://www.scientificamerican.com/article/graphic-science-how-much-do-fires-cost-property-damage/
The ecological sustainability of slash-and-burn agriculture
Wildfire Causes and Evaluations
U.S. Fires Quadrupled in Size, Tripled in Frequency in 20 Years
https://eos.org/articles/u-s-fires-quadrupled-in-size-tripled-in-frequency-in-20-years
FAQs
Are all forest fires bad? ›
The benefits of forest fires
Although wildfires in the news are often harmful, most wildfires are good. Many fires actually help the environment. Natural fires were part of the world well before humans evolved.
Many ecosystems benefit from periodic fires, because they clear out dead organic material—and some plant and animal populations require the benefits fire brings to survive and reproduce.
Why are forest fires not always bad? ›Sometimes, these necessary fires occur naturally. For example, a thunderstorm may send a lightning bolt into a forest, starting a wildfire that burns away some of the unwanted underbrush. Unfortunately, these wildfires may also burn good trees in the process.
What are the positives of wildfires? ›Fire is part of a cycle in most ecosystems. It reduces dead vegetation, stimulates new growth, and improves habitat for wildlife, many of the details park visitors imagine when they think of a national park.
Can forest fires be natural? ›Wildfires do sometimes occur naturally, either ignited by the sun's heat or a lightning strike. However, most wildfires are caused by human activities, including unattended campfires, discarded cigarettes, arson and more.
Is all fire bad for the environment? ›All open burning poses risks to the environment and public health. Smoke pollutes the air we breathe. Ash pollutes our soil, groundwater, lakes, rivers and streams. Burning anything in the outdoors can cause a wildfire.
Should we let forest fires burn? ›Controlled burns can minimize insects and disease and improve the habitat for threatened and endangered animal species. Prescribed burns provide key nutrients to soil, which help trees and vegetation flourish. These controlled forest fires also open up the tree canopy to allow sunlight into the forest.
Do forest fires help forests? ›Forest fires help in the natural cycle of woods' growth and replenishment. They: Release seeds or otherwise encourage the growth of certain tree species, like lodgepole pines. Clear dead trees, leaves, and competing vegetation from the forest floor, so new plants can grow.
Are wildfires getting worse or better? ›Unfortunately, yes. Changes in our climate, along with other factors, have led to wildfires increasing in intensity, severity, size and duration.
Will forest fires get worse? ›“We're already seeing fires that we didn't expect to see until 2080.” As of 2021, the average surface temperature of the U.S. was roughly 2.5 degrees Fahrenheit. That figure is projected to rise by 3 to 12 degrees Fahrenheit by 2100, resulting in more frequent and intense heat waves.
Are forest fires increasing? ›
The extent of area burned by wildfires each year appears to have increased since the 1980s.
Can wildfires be stopped? ›Firefighters control a fire's spread (or put it out) by removing one of the three ingredients fire needs to burn: heat, oxygen, or fuel. They remove heat by applying water or fire retardant on the ground (using pumps or special wildland fire engines) or by air (using helicopters/airplanes).
What are the pros and cons of fire? ›...
What are the advantages and disadvantages of Fire.
| Advantages | Disadvantages |
|---|---|
| Cooking and heating | Dangerous and destructive |
| Clearing land | Air pollution |
| Signaling and communication | Wildlife displacement |
| Metalworking and ceramics | Limited resources |
Fire is often associated with negative impacts on the environment. We usually think of the damage and devastation fire causes to wildlife and vegetation, but a fire event can also be beneficial for our plants and animals. For example, fire: heats the soil, cracking seed coats and triggering germination.
Can a wildfire have a positive impact on the ecosystem? ›Fire can act as a catalyst for promoting biological diversity and healthy ecosystems, reducing buildup of organic debris, releasing nutrients into the soil, and triggering changes in vegetation community composition.
Do any trees survive forest fires? ›Ponderosa pine can survive up to 75% crown scorch, Douglas-fir can tolerate up to 50% scorch. Bark scorch The inner bark (phloem) is the sugar conducting tissue in trees, and is vulnerable to excessive heat. If the fire was fast moving or was a light ground fire, the bark may provide enough protection for the phloem.
Do forests grow back after fire? ›Depending on the severity of the wildfire, a forest may recover quickly. (The low-intensity “prescribed fires” used by forest managers, for example, are intended to add nutrients to the soil and rejuvenate plant life.) For larger, more destructive wildfires, active efforts to assist recovery are often needed.
Do trees survive forest fires? ›They can't run, fly, creep or crawl out of a fire's path. But they have adapted to survive, and even depend on, regular fire. From armoring themselves with thick bark to developing ways to protect precious seeds, trees have developed several fascinating adaptations in response to a predictable fire pattern.
What will happen if wildfires continue? ›Every year, there are an estimated 340,000 premature deaths from respiratory and cardiovascular issues attributed to wildfire smoke. The increasing frequency and severity of wildfires pose a growing threat to biodiversity globally. Individuals, companies and public authorities also bear great economic costs.
How do wildfires stop naturally? ›The four weather elements responsible for either the spread of fire or natural wildfire suppression include temperature, precipitation, relative humidity, and wind speed. Specifically, a significant decrease in wind speed and an increase in relative humidity are the two primary factors of how wildfires stop naturally.
What was the worst wildfire in history? ›
| Year | Size | Name |
|---|---|---|
| 1845 | 1,500,000 acres (610,000 ha) | The Great Fire |
| 1865 | 1,000,000 acres (400,000 ha) | The Silverton Fire |
| 1853 | 450,000 acres (180,000 ha) | The Yaquina Fire |
| 1868 | 300,000 acres (120,000 ha) | The Coos Fire |
Controlled burns are lit for a number of reasons. By ridding a forest of dead leaves, tree limbs, and other debris, a prescribed burn can help prevent a destructive wildfire. Controlled burns can also reduce insect populations and destroy invasive plants. In addition, fire can be rejuvenating.
Is burning good for the land? ›Fire can increase the availability of many important soil nutrients such as calcium, phosphorus, and nitrogen and can increase soil pH. Burning can stimulate new plant growth in cattle-grazing lands and can be used in crop lands to help cycle nutrients prior to planting. Native plant communities.
Are forest fires bad for climate change? ›Yes. Wildfires release carbon dioxide (CO2) emissions and other greenhouse gases (GHG) that contribute to climate change.
Why is fire important to humans? ›Humans have long used fire for heating, cooking, landscape management and agriculture, as well as for pyrotechnologies and in industrial processes over more recent centuries. Many landscapes need fire but population expansion into wildland areas creates a tension between different interest groups.
Why are wildfires so hard to put out? ›The main reason wildfires can get out of control is quick spread and a lack of detection. Firewatch towers, aerial detection, and other methods are only so effective at identifying new fires on flammable land.
Are wildfires a big problem? ›Wildfires can disrupt transportation, communications, power and gas services, and water supply. They also lead to a deterioration of the air quality, and loss of property, crops, resources, animals and people.
Why are wildfires so bad now? ›Drivers of change. Climate change and forest degradation and fragmentation have led to more fire-prone conditions globally. With hotter and drier conditions, fires - either ignited by humans or by lightning - are more likely to burn over larger areas and at hotter temperatures.
Will future wildfires be more extreme? ›A model developed for California's Fourth Climate Change Assessment projected up to a 77 percent increase in average area burned and a 50 percent increase in the frequency of fires exceeding 25,000 acres by 2100.
Are wildfires predicted to become worse in the future? ›With continued high emissions of greenhouse gases, models project that the risk of very large wildfires will increase by up to six-fold in parts of the United States by mid-century.
How bad are forest fires this year? ›
The National Interagency Fire Center (NIFC) statistics show that as of Dec. 30, 2022, 66,255 fires had burned a total of 7,534,403 acres. These figures are higher than the ten-year average of 59,733 fires and 7,333,776 acres.
What is the future of forest fires? ›Published. Climate change and land-use change are projected to make wildfires more frequent and intense, with a global increase of extreme fires of up to 14 per cent by 2030, 30 per cent by the end of 2050 and 50 per cent by the end of the century, according to a new report.
Why are wildfires getting bigger? ›Climate change affects wildfires by exacerbating the hot, dry conditions that help these fires catch and spread. As global temperatures rise, we expect the size, frequency and severity of wildfires to increase in the years ahead.
How do you solve forest fires? ›- Obey local laws regarding open fires, including campfires.
- Keep all flammable objects away from fire. ...
- Have firefighting tools nearby and handy.
- Never leave a fire unattended.
- Carefully dispose of hot charcoal.
- Drown all fires.
- Carefully extinguish smoking materials.
Aside from the extended duration of fire season, fires are also lasting longer. According to Face the Facts USA, wildfires in the US before 1986 lasted an average of 8 days. In 2013, that average was 37 days. Fires are also burning up more acreage.
Does wildfire smoke ever go away? ›Eventually, whether it's in one day or a full month, these smoke particles will fall back to Earth. Often, these particles contain nutrients like potassium and nitrogen from the plants that burned in the original fire, and can help fertilize the soil.
How long do wildfires last? ›Before 1986, a wildfire was contained on average in less than eight days. Since then, the average wildfire has burned for 37 days. Today's photo gallery includes more details.
What three things start a fire? ›Oxygen, heat, and fuel are frequently referred to as the "fire triangle." Add in the fourth element, the chemical reaction, and you actually have a fire "tetrahedron." The important thing to remember is: take any of these four things away, and you will not have a fire or the fire will be extinguished.
How do wildfires start? ›Nearly 85 percent* of wildland fires in the United States are caused by humans. Human-caused fires result from campfires left unattended, the burning of debris, equipment use and malfunctions, negligently discarded cigarettes, and intentional acts of arson. Lightning is one of the two natural causes of fires.
What country is most affected by wildfires? ›... list of the 20 countries most affected by wildfire disasters in terms of economic damage since the beginning of the last century is given in Table 3. The US is the country with the highest economic losses, followed by Indonesia and Canada. ...
How do you survive a wildfire? ›
- Stay calm.
- Go to an area clear of vegetation, a ditch or depression on level ground if possible.
- Lie face down, cover up your body.
- Use your cell phone to advise officials—call 911.
According to federal data cited by the National Park Service, humans cause about 85 percent of all wildfires yearly in the United States. The Annual 2021 Wildfires Report from the National Centers for Environmental Information indicates that over 7 million acres of wildland were consumed by fire that year.
How did fire help early humans? ›Fire provided a source of warmth and lighting, protection from predators (especially at night), a way to create more advanced hunting tools, and a method for cooking food. These cultural advances allowed human geographic dispersal, cultural innovations, and changes to diet and behavior.
What happens to animals during a wildfire? ›Loss or contamination of shelter, water, and food are the immediate effects on wildlife following a fire. As such, animals are forced to move elsewhere in search of sustenance and new territory.
Are wildfires worse than they used to be? ›Unfortunately, yes. Changes in our climate, along with other factors, have led to wildfires increasing in intensity, severity, size and duration.
What is the difference between a forest fire and a wildfire? ›Forest fires are caused by natural or artificial fires linked to land clearing and deforestation in tropical, temperate, and coniferous forests. On the other hand, a wildfire is a spontaneous, uncontrolled fire in a natural woodland, grassland, or prairie setting.
Are natural fires bad? ›Fire is a natural phenomenon that serves important ecological purposes, and some wildfires are beneficial for ecosystems. But climate change and other factors are contributing to more uncontrolled, disastrous wildfires that damage ecosystems, harm communities, and kill residents and firefighters.
Why are wildfires so much worse now? ›He is among several experts who say a confluence of factors has driven the surge of large, destructive fires in California: unusual drought and heat exacerbated by climate change, overgrown forests caused by decades of fire suppression, and rapid population growth along the edges of forests.
Can you outrun a forest fire? ›Fire can move like a freight train – many times faster than you can run. Get away as quickly as you can. Especially if you actually see flames. If a fire starts growing quickly, you won't be able to outrun it.
How can we stop wildfires? ›- Check weather and drought conditions. ...
- Build your campfire in an open location and far from flammables. ...
- Douse your campfire until it's cold. ...
- Keep vehicles off dry grass. ...
- Regularly maintain your equipment and vehicle. ...
- Practice vehicle safety.
Do firefighters fight forest fires? ›
The U.S. Forest Service has more than 10,000 professional firefighters that respond to thousands of wildfires each year on National Forest System land as well as on land under the jurisdiction of other Federal, tribal, state, and local agencies.
Can a safe survive wildfire? ›Yes. Fireproof safes can survive wildfires but only if they are not subjected to temperatures and durations in the fire that exceed their ratings. To ensure that a fireproof safe will survive a wildfire, it must be rated to the fire duration and temperature that exists in the wildfire.
Do forests grow back better after fire? ›Depending on the severity of the wildfire, a forest may recover quickly. (The low-intensity “prescribed fires” used by forest managers, for example, are intended to add nutrients to the soil and rejuvenate plant life.) For larger, more destructive wildfires, active efforts to assist recovery are often needed.