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Did you know that even forest fires can be good things? It is true. If they are planned correctly forests fires can be very beneficial to the environment. 

Controlled fires are fires that are set on purpose in order to burn away material that could be harmful later. They are carefully watched by firefighters to makes sure that they don't get out of hand. Controlled fires burn away ground litter that is potentially flammable. These ground wastes such as dead leaves, herbaceous plants, little shrubs, and dead plants can fuel a fire caused by natural means (like a lightning strike), and lead to disaster. 
 
 
Fire sweeps through ground litter.

Small amounts of ground litter reduce the risk for large-scale, uncontrolled fires. Burning also manages the vegetation in a way that can enhance the productivity and the diversity of animals and plants. It helps maintain and restore failing ecosystems.

By burning dead or troublesome plants, there is room for native plans to grow. It creates attractive habitats for animals and other plants to migrate into and add to the ecosystems. The burning is also a good way to focus on a specific area of need, like helping an endangered species or to reduce the amount of invasive or unwanted plants. There are also some kinds of nutrients that are only released in the soil if there is extreme heat, such as in a fire. 

There are a lot of factors that firefighters must watch in order to create a safe and helpful controlled burn.

Weather is thought of to be the most important thing when it comes to the success of a controlled burn. It affects the behavior of the fire and smoke. It also affects the ability a fire fighting team has of keeping the fire contained. There are many different aspects to weather, but of few of these are really important to those who conduct controlled burns. 

1.Wind speed and direction 

2.Relative humidity 

3.Temperature 

4.Amount of sunlight 
 
A helicopter helps to fight a fire that has gotten out of control.

With prescribes burns, some wind movement is preferable, because you can then predict where the fire will move. Steady winds between 5 and 18 mph are best. Winds around 2 or 3 mph would not allow for quick fire spread.

The burn would take longer to be completed and this would mean higher costs to contain it. The fire may also create its own wind that could move it in a different direction that firefighters weren't prepared for. Not only that, but slower fires mean longer exposure of plant species to heat. This may damage some plants.

Also, when winds are too gusty, it is also not a good idea to conduct a controlled burn. The gusts can mean that unstable weather could happen, which could lead to changes in direction of wind or the amount of water in the air. This could make it very hard to have a successful burn. Any severe change in wind creates immediate concern for the firefighters because smoke could escape the areas where the firefighters want the fire to stay. That means that big problems could happen and that people, the environment, animals, and plants could get hurt.

Some other weather factors are also very important to firefighters. Relative humidity is a measure of the actual amount of moisture in the air, compared to the total amount that the air is capable of holding at that temperature and pressure.

Why do you think relative humidity is such an important factor in controlled burns?

When the air is too dry the fire can spread much more easily.

When the air is too wet, the fire won't even start.


 
 
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