The Two Faces of Fire
BY AWAKE! WRITER IN AUSTRALIA
FIRE can be a friend or a foe. Fire can rejuvenate a landscape or devastate it. Large fires can develop into extremely destructive forces very difficult to control.
One example of the widespread destructive fury generated by fire is what took place in Indonesia in 1997. In that year bushfires ravaged the country, causing immense damage to the land, people’s health, and the economy. And devastating smoke from those fires spread to neighboring countries—eight in all—affecting an estimated 75 million people. Reports indicate that 20 million were treated for such conditions as asthma, emphysema, and cardiovascular diseases as well as eye and skin problems.
In Singapore, pollution rose to ominous levels. The city was blanketed by smoke. “We are all prisoners in our homes,” lamented one resident, afraid to venture out of her air-conditioned house. On the worst days, people could not see the sun through the haze.
The following year, 1998, saw 8,000 residents of British Columbia, Canada, forced to leave their homes as an inferno rapidly approached. That fire was just one of almost a thousand that raged throughout Canada that year—115 of which were at some point considered to be out of control. One fire in northern Alberta, Canada, consumed 90,000 acres [35,000 ha] of forest. A resident remarked: “It looked like a nuclear bomb had gone off. There was this humongous black cloud hanging over the community.”
Fire’s Dangerous Face
Fire is one of the powerful forces of nature. A raging bushfire can reshape the land, change the balance of plant species, alter the wildlife community, and threaten life and property.
A severe fire can promote erosion. When ground is bared to heavy rains, which often follow a hot summer, exposed soil is washed away. Plant species are affected by this. Some of the more sensitive species suffer and die, while others adapt well. Unfortunately, those that thrive are usually noxious weeds, which tend to take over the landscape at the expense of native flora.
Animals that rely on specific native plants are then also threatened. In Australia native mammals such as koalas and brush-tailed possums are endangered species that could easily face extinction if too much of their native habitat is destroyed by fire. Over the past 200 years, the Australian continent has lost 75 percent of its rain forests, 66 percent of its tree cover, 19 mammal species, and 68 native plant species, most of which are not found anywhere else in the world.
As cities have encroached farther into the surrounding bush, people have become increasingly vulnerable to the devastating effects of bushfire. In December 1997, more than 600,000 acres [250,000 ha] were in flames as hundreds of fires raged in suburbs of Sydney, Australia, and in several small towns around the Blue Mountains. About half of those fires burned out of control. The fire-services commissioner said that they were the worst fires he had seen in 30 years. Hundreds were forced to evacuate their homes, some losing them to the flames. The fires also claimed two lives. Beginning in late December 2001, bushfires thought to have been caused by arsonists devastated 1.9 million acres [753,000 ha] of bush.
When Fire Threatens
Several factors can be responsible for out-of-control fires. One natural factor is the El Niño-related weather pattern, a climatic phenomenon that periodically causes hot, dry weather conditions around the world. Any land that comes under El Niño’s unseasonably dry spells has the ideal ingredients for starting a fire.
More frequently, the thoughtless activities of humans are to blame for raging fires. Deliberately setting the landscape ablaze is considered a criminal offense in many countries. It has been estimated that arson or accidents have started over half of the fires in state forests in New South Wales, Australia.
The irresponsible treatment of the environment is another factor that can lead to serious fires. Through deforestation and logging, forests are becoming more flammable. The fuel layer that a fire depends on is increased by the woody debris that often results from logging operations. Logging also opens up the leaf canopy, allowing sunlight to penetrate the fuel layer, drying it out. Once a spark ignites this volatile combination, the resulting fire can easily get out of control.
Economic considerations can also exacerbate the problem of major fires. In Indonesia slash-and-burn farming has been used for centuries in agriculture with little effect on the balance of nature. When farmers use fire carefully and in a controlled manner, it has about the same effect on the environment as natural fires. In recent times, however, traditional slash-and-burn farming has increased in scale, becoming industrialized. With the growing worldwide demand for such products as palm oil, forests have been razed to be replaced by fast-growing, cash-earning plants. The easiest and cheapest way to clear the land is by burning the natural vegetation. Thus, people burn thousands of acres with scant regard for the long-term benefits of retaining adequate forest areas.
Fire’s Friendly Face
Although fire can wreak havoc and destruction, it can also have a very positive effect on many species of plants and animals. In fact, it can even play an essential role in keeping nature’s balance. How does it do this?
Fire is one of man’s oldest friends. It has kept him warm, given him light, and cooked his food. Indigenous Australians have used fire for centuries as part of their daily routine. Fire is so important to the native Yanyuwa people that they have more than a dozen words to describe the different types of fire and their effects. For example, they might use the word kambambarra when speaking of a bushfire or wildfire. The word warrman is used to describe well-burned country, which is good for hunting. Smoke billowing upward and forming a cloud is known as rrumarri.
These indigenous people use what has been called fire-stick farming to manage the land they live on. They use small, low-intensity fires to reduce the buildup of dead, dry plant matter, which is the main fuel for wildfires. Controlled use of fire in this way has enabled the Aborigines to live off the land effectively while maintaining the habitat of plants and animals. It has also decreased the risk of people being caught in dangerous wildfires.
The Value of Prescribed Burning
When European settlers came to Australia a little more than 200 years ago, this delicate balance between man, nature, and fire began to be disturbed. From the European viewpoint, fire was something to be suppressed. Fires became less frequent, but because of the buildup of fuel, the fires that did occur became more intense and hard to control. In recent times, however, governments have learned from the practices of native Australians and have developed a strategy called prescribed burning. This method allows fires to burn in a controlled way to prevent more disastrous conflagrations. Small fires are lit outside of the bushfire season. These fires are slow moving, have low flames, and remove litter without disturbing the trees. Generally, the evening dew puts them out.
The aim of bushfire management using prescribed burning is to protect life and property while also maintaining the diversity of native plants and animals. And prescribed burning reduces the aggressive spread of some introduced weeds. It also helps to maintain diversity of habitats needed for the conservation of native animals.
Certain species of plants seem to rely on fire to help germinate their seeds. Some have such hard outer shells that fire is needed to crack them open to allow moisture to seep in. Research indicates that the smoke from a fire also helps seed germination. There are some 70 components in smoke that are thought to be possible triggers for seed germination, an important one being nitrogen dioxide.
Freshly burned land results in soils that are rich in such nutrients as nitrogen and phosphorus. The fire releases nutrients stored in leaf litter, allows more sunlight to penetrate to the ground, and creates an ideal seedbed for new plants to take root. Wattles, or acacias, for example, reseed after a fire and tend to thrive in the conditions that a fire leaves behind.
Many animals also seem to benefit from postfire conditions, especially from the new growth of vegetation, which they find more tender and succulent. Some species of kangaroos and wallabies favor frequently burned forest and are said to be fire dependent. This is because the plants they rely on for food and shelter are in turn dependent on fire for regeneration and maintenance.
Still Much to Learn
The two faces of fire are becoming better understood, but fire’s interaction with the environment is complex, and there is still much to learn. How fire affects specific species of plants and animals is something that needs more study. How fire interacts with and affects our ecology on a broader scale also needs more research. Some questions to be answered are: Do fires contribute to the greenhouse effect? What impact does the smoke from fires have on weather patterns? How do fires behave?
Currently, there are computer programs, called models, that are designed to predict fire behavior. They work by interpreting data on fuel as well as on temperature, wind speed, and other weather conditions. Unfortunately, at present the models are not always accurate, and they cannot predict unusual phenomena such as fire flashes or sudden blowups. In the Sydney fires of 1997, two experienced fire fighters lost their lives as a result of one of these flashes, which are appropriately termed “fingers of death.”
Large fires can be especially difficult to predict because they can generate their own weather, including strong winds, clouds, and even thunderstorms. Their winds can change direction or speed suddenly, making the fire unstable. Researchers hope to improve current models by including these factors along with other information, such as the type and slope of the terrain and the fuel distribution.
One project toward this end in the United States is being undertaken by the National Center for Atmospheric Research (NCAR) in Colorado. NCAR has outfitted a C-130 transport aircraft with state-of-the-art scientific equipment and seven on-board computer workstations, all protected by heavy insulation. The aircraft has been designed to fly over a raging fire and take data samples with sensors fitted on the wings. This data is then sent to the computers for processing. The plane has an infrared camera called Thermacam, which can show the relative intensity of each part of the fire. In these ways NCAR scientists are learning to improve current fire behavior models.
It is hoped that these improved models will enable experts to control fires more safely. The ability to predict accurately what a fire will do could also reduce the risks that fire fighters face to protect the community.
Yes, fire can be a devastating and destructive enemy when out of control, but it can also be a good friend. It plays an essential part in the cycles of nature that the Creator has put in place to rejuvenate the earth and to keep a balanced variety of plant and animal life.
[Picture on page 25]
Stunned elk avoid a fire sweeping through Montana’s Bitterroot River valley
John McColgan, BLM, Alaska Fire Service
[Picture on page 26]
A prescribed burn in Australia
Photo provided courtesy of Queensland Rural Fire Service