The Basics of Fire

Fire is a natural part of many landscapes, and the frequency, intensity and duration of wildfire can be controlled through land management activities. Fire can be ignited by lightning strikes, volcanic eruptions, and human activity like clearing brush or logging. Climate change is increasing the number and severity of fires by prolonging droughts and driving higher temperatures.

Fire is the visible effect of a special type of chemical reaction called combustion. This reaction happens between oxygen in the air and some sort of fuel (like wood or coal). When the fuel is heated enough, it releases more energy than it takes to start the process. This extra energy causes the reaction to continue as long as there is fuel and oxygen. The fuel and oxygen are sometimes referred to as the fire triangle. The reaction that produces a flame burns fuel at a very high rate. This process is called incomplete combustion and produces products such as carbon dioxide and water. The burning gas, or diffusion flame, emits light in the visible and infrared spectrum. This light gives a familiar yellow or orange glow and often produces smoke.

The combustion of other types of materials, such as plastics or rubber, usually occurs at a lower rate and produces less heat. When the fuel is wood, it can burn at a very fast rate and produce large amounts of heat. This heat and pressure radiates outward, forming the familiar flame and making a room feel warm. Some materials do not react at all, or burn very slowly. These are known as class A combustibles, and include wood, paper, cloth, and some rubbers and plastics. These can be extinguished by cooling them to a temperature below their ignition temperature.

Most people are curious about fire, but it is important to understand how it works before trying to play with it. Children, in particular, should not be allowed to play with matches or lighters because they can easily start a fire. This can be dangerous for many reasons, including the risk of injury or death. It is also important to keep in mind that even small fires can be very dangerous. When playing with a torch or fireplace, it is a good idea to wear sturdy shoes and keep a fire extinguisher close at hand in case of an emergency. In addition, people should remember that while fire is a natural and important part of many landscapes, it can be dangerous and cause damage if it is not properly managed. Periodic low-intensity fires rejuvenate wildlife habitat and promote healthy plant regrowth. This helps to ensure that habitats can sustain wildlife over the long term. It also allows nutrients that were bound up in dead or decaying vegetation to return quickly to the soil where they can be used by roots and microorganisms. If this cycle is disrupted, ecosystems can become depleted of essential nutrients. Periodic fires, such as those prescribed by foresters, help to prevent this problem.