Fire Ecology

• Topics that will be covered

History of FireWhat is FireKinds & types of FiresWhat is needed for a burn

History of FireFire has been recorded since the European settlers came to N.America, noted used for clearing land, hunting and gathering activities, and in warfare.

Native Americans had fire firmly rooted in their way of life

Post-Columbian immigrants did not embrace fire as a natural process (agricultural crops and communities of wooden homes were not adapted to the natural cycle of fire.

As populations boomed, careless and ignorant use of fire resulted in conflagrations.

Oct. 8, 1871 two of the greatest natural catastrophes in the history of the Middle West.

Peshtigo, Wisconsin fire of 1871 left 1,300-2,500 dead and over 1,000,000 acres burned.

The Great Chicago Fire, burning for 36 hours, the inferno destroyed three and a half square miles in the heart of the city, leveling more than 18,000 structures. One-third of the city's 300,000 residents lost their homes, and at least 300 died.

1880 Fire Study

USA on fire in1880 USA on fire in1880

Forest Reserve Act of 1891 authorized withdrawing land from the public domain as “forest reserves” managed b the Dept. of Interior.

1901 renamed the Bureau of Forestry.

1905 transferred management, henceforth known as the USDA Forest Service.

Gifford Pinchot was the first Chief Forester of the USFS

Main purpose was “Fire Suppression”

1937 President Roosevelt started campaign to reduce the number of fires caused by people 40 million ac. Each year Uncle Sam as a forest ranger, “Your Forests – Your Fault – Your Loss”

Dec. 7, 1941 Pearl Harbor Attacked

Spring 1942 submarine surfaced near coast of Southern California and fired shells that exploded on an oil field near Santa Barbara.

Americans feared that exploding shells could set off numerous raging forest fires.

Protection of these forests became a matter of national importance.

Posters and slogans were created by the War Advertising council.

WW II Posters

Propaganda?The movie Bambi was released 1942 (based on the 1923 book Bambi, A Life in the woods by Felix Salten.)

Disney loaned “Bambi” to the forest service for one year.

Disney Disney2

Questions

How did the movie depict fire?

What was the cause of the fire?

What should be done?

Who were the forest service targeting when using Bambi as a spokesperson?

New Spokesperson

Had to come up with new campaign

1944 Came up with Smokey Bear (named after NY fire chief)

Is the longest running public service campaign in US history

Name this character.......

Finish that slogan, Only you...........

Smokey is one of the world's most recognizable fictional characters.

Smokey's image is protected by US Federal Law

Smokey's message has been the same for 50 years, changed in 2001

Real Smokey1950 in the Caipitan Mts of New Mexico huge wildfire that caught 24 men. Barely escaped, when fire was passed the only thing left was a small bear cub.

In the 1960s, when it was realized that no new Giant Sequoia had been grown in the forests of California, they began to question if fire suppression was the best policy.

Why were there no new trees?

The passage of the 1964 Wilderness Act encouraged the allowance of natural processes to occur, including fire. Fires were to be allowed to run their courses as long as they could be contained within fire management units and accomplished approved management objectives. Several parks established fire use programs, and policies were gradually changed from fire control to fire management

FIRE TRIANGLE

Fire Behavior

What is Fire?

Fire is a chemical reaction, and flame is the visible indication of that chemical reaction. When a flame is visible, the combustion is termed "flaming combustion." With "glowing combustion" one will only see embers. Fuels char at relatively low temperatures, but once charred can continue to burn by glowing combustion. As fire spreads, there is constant ignition of new fuels through one of the three heat transfer mechanisms described earlier, and the fire continues to advance.

A heat source is responsible for the initial ignition of wildland fire, and heat is also needed to maintain the fire and permit it to spread. Heat allows fire to spread by removing the moisture from nearby fuel, warming surrounding air, and preheating the fuel in its path, enabling it to travel with greater ease.

HeatHeat can be transferred in three ways:

1. Radiation - a ray or wave; heat energy in the form of invisible light called infrared radiation; transferred through empty space. Radiation can dry surrounding fuels and sometimes ignite them.

2. Convection - heat is transferred through liquids and gases by means of up-and-down movements called convection currents. As temperature rises, convection increases as molecules move faster and become less dense. An example of this is a smoke column above the fire or smoke rising up a chimney. Hot gases and embers from it can dry and ignite other fuels.

3. Conduction - heat is transferred through the fuel, or from one fuel to another by direct contact of molecules.

   

                                                               

   

Fuel could be defined as any kind of combustible material, and is characterized by its moisture content, size and shape, quantity, and the arrangement in which it is spread over the landscape. The moisture content of any fuel will determine how easily that fuel will burn

Fuel1. Moisture - how well a fuel will ignite and burn is dependent upon its moisture content or chemical composition.2. Size and shape - light fuels such as shrubs, grasses, leaves and pine needles burn rapidly but are easily extinguished. Heavy fuels such as logs and limbs burn more slowly.3. Fuel loading - the quantity of fuels in an area which is available for combustion4. Horizontal continuity and vertical arrangement - the manner in which fuels are spread over a certain area.

Air contains about 21% oxygen, and most fires require at least 16% oxygen content to burn.

Oxygen supports the chemical processes that occur during a wildland fire. When fuel burns, it reacts with oxygen from the surrounding air releasing heat and generating combustion products (i.e. gases, smoke, particles). This process is known as oxidation.

OxygenOxygen is available in the air. When windy conditions prevail, the supply of oxygen available to a fire is replenished more quickly than in still air because a greater volume of air flows over the fire. The rising column of hot air generated by a fire draws in cooler, oxygen-rich air from the surrounding air mass, creating a fire-driven wind that helps a fire sustain itself as long as fuel is available.

                       

   

The interaction of the three equal sides of the fire triangle: heat, fuel and oxygen, are required for the creation and maintenance of any fire. When there is not enough heat generated to sustain the process, when the fuel is exhausted, removed, or isolated, or when oxygen supply is limited, then a side of the triangle is broken and the fire is suppressed.

Fire Behavior triangle

Consideration of fuels, topography and weather of a location can give an indication of areas that may be more at risk during a major wildland fire.

Topography

1. Aspect - the direction in which a slope faces relative to the sun2. Slope - the amount of degree of incline of a hillside. The steeper the slope, the faster the fire burns up or down (depending on wind direction)3. The shape of the country – box canyons, narrow canyons, and other rugged topographic features can influence the wind’s speed and direction

Two types of fires

Prescribed Fire -refers to the controlled application of fire to wildland ecosytems under specified environmental conditions that help restore health to fire-adapted environments.

Wildfire- is the term applied to any unwanted, unplanned, damaging fire burning in forest, shrub or grass.

Three kinds of fires

Ground fires burn in natural litter, duff, roots or sometimes in high organic soils.

Once started they are very difficult to detect and control.

Surface fires burn in grasses and low shrubs or in the lower branches of trees.

Surface fires may move rapidly.

Ease of control depends on the fuel involved.

Crown fires burn in the tops of trees.

Once started, they are very difficult to control because wind plays an important role in the fire behavior.

Spotting can be produced by crown fires as well as wind and topographic conditions. Large burning embers are thrown ahead of the main fire.

Once spotting begins, the fire will be very difficult to control.

Why do we burnThe objectives of prescribed burning are:Fuel reductionPreparation of seedbeds for regeneration of wind-disseminated species which become established most readily on bare mineral soilControl of competing vegetationImprovement of grazingManagement of wildlife by allowing species that they feed on to growRecreation management to maintain a park-like appearanceThinning of saplingsControl of pests

Characteristics of WeatherTemperature - fuel and ground temperatures are primarily due to direct radiation from the sunWind - encourages combustion and the spread of fireRelative Humidity - is an expression of the actual amount of moisture in the air compared to the total amount the air is capable of holding at that temperature and pressure. Precipitation - fuel moisture is affected by the amount and also the duration of the precipitation.

Factor Preferred Range Limit

Temp 55-80 50/85

Wind Speed 1-15 mph 20 Wind Direction Steady from one

direction

Relative Humidity 40-70% 30%

Cloud Cover Clear - 0.7(70%)

Ceiling 2,000-unlimited

What to wearShoes/boots: Must be Leather! They can be tennis

shoes or boots but they must be leather. Anything else will run the risk of melting. As it turns out, your feet will generally experience the least amount of heat.

Pants: Cotton! Cotton! Cotton! Loose blue jeans work great. Tight blue jeans work but transfer heat more quickly to your skin. Army BDUs (Battle Dress Uniform) are the best. Make sure the BDUs are cotton!

Body layer shirt: Cotton short sleeve. Just a cotton t-shirt will work.

Middle layer shirt: This should be a medium-weight cotton long-sleeve shirt. I have found that denim shirts are the best. Long sleeve cotton t-shirts work but are not as durable or insulative as denim.

What to Wear cont.Outer jacket: Cotton! This garment is going to absorb the most heat and take the most abuse. You want a durable denim coat for this job. You can use a lightly insulated jacket in this position too. The insulation protects you from the heat. On cool to mild days I use an insulated jacket.

Gloves: Leather gloves. Welding gloves rock! Thin leather gloves are better than nothing, but thick gloves are the best.

Bandana: Cotton

Ball cap: Make sure your hair is tied up.

Why no Synthetics? Synthetics have a lot of benefits, but their major

draw back when it comes to firefighting is their low melting temperature. This melt temperature, while low compared to cotton, is still very hot. Imagine how hot it would be if plastic was melted onto your skin. Chances are it will not only be hot, it will also be on fire. When it cools it must be peeled and cracked off. If your skin is intact, this just hurts. It is impossible if you have actually been burned. So no synthetics! You will not be allowed to burn if you show up in any synthetic clothing, or missing ANY of the other essential pieces of clothing

Equipment Igniting and controlling the fire• Drip or flame torch• Backpack water tanks• Flapper/swatters• 5 gal buckets of water on hand• Leaf rakes• Fireproof brooms soaked in

water

DefinitionsFire Boss: A person that supervises all phases of the application of a prescribed burn.

Firebreak: A space which is clear of flammable materials to stop or check fires.It also serves as a line from which to work and facilitate the movement of personnel and equipment. Firebreaks should be twice as wide as the tallest adjoining herbaceous material and never less than six feet wide. Firebreaks can be either burned or cleared.

Burned Firebreak: Burned firebreaks are established along the perimeter of the burn area, taking advantage of natural barriers, mowed and raked wet lines. These boundaries may be burned in the evenings when the fire is more easily controlled. Pre-burned firebreaks shall be lit again before the headfire is started to ensure that there is not unburned fuel still present on them.

Head Fire

Head fireHead fires are set with the wind direction and should only be used by experienced professionals under ideal fuel conditions. Often set after a rain, head fires are the most economical and the most dangerous type of prescribed fire. Head fires burn quickly, have a taller flame, and can kill even large trees if used improperly. If used properly, they are very effective at maintaining early successional wildlife habitat.

BackfireA backfire is set at a 90-degree angle to the wind direction so the fire burns directly against the wind. This is one of the safest methods of prescribed burning and is recommended for beginning wildlife managers or where there are fire hazards, such as adjacent lands with high danger fuels. Wind speed should be no more than 6 to 10 mph. At night, backfires normally move about 1 chain (66 feet) per hour. If the wind speed is 20 miles/hour, the fire will back twice as fast (132 feet/hour).

Backfire

Flank Fire

Flank fires are often used when the fuel is relatively light. These fires are set by an individual or individuals walking into the wind and are relatively safe.

Ring FireRing Fire: This technique requires a firebreak downwind that provides adequate width to prevent escape of the fire. Once the firebreak is secure, the remaining sides of the burn should be lit as rapidly as possible. The resulting headfire will spread rapidly across the area. Ring fires are the safest because once the ring is closed and the perimeter fires are extinguished there is little chance for the fire to escape. Ring fires should be used where brush control, weed control, and mulch removal is the reasons for burning.

Strip HeadfireA technique that requires setting a line or series of lines upward from a firebreak so no single line can develop enough heat or convection to escape or cross the firebreak. The width of the strips depends on fuel type, amount, slope, and uniformity. It is most useful to widen firebreaks and burn areas adjacent to hazards (controls size of fire and amount of smoke). Its disadvantages are the high heat concentration as the lines come together and the necessity of a well developed firebreak.

• Why and where do we burn at

Northwest?

• What is done to prepare for a

burn?

• What equipment is used?

• How do we decide when to burn?

• How is a burn conducted?

• How can you help?

Here’s a few of the questions I’d like to answer for you today:

Preparation for a burn

• Firebreaks

• Checking for dead timber

• Burn prescriptions

So that is where and why we burn at CERA. Now, what is done to prepare for a

burn?

Preparation for a prescribed burn involves establishing firebreaks, checking for dead

timber (when burning in savannas and woodlands), and developing a burn

prescription.

Burn prescription

Burn unit map

Equipment

Personnel

Weather parameters

Emergency contact information

The firebreaks are usually maintained months before a burn or at least a few days

ahead of time if a rake is available. Dead trees can be raked around a day in

advance, and/or watered down minutes before the area is to be burned. A burn

prescription should at least be in draft form prior to establishment of firebreaks.

A burn prescription is a document that is specific to a burn unit. For example, at

CERA, we can prepare a burn prescription specifically for the “Fall burn prairie”

near the entrance. It contains a map of the burn unit and surrounding area, the

preparation and location of firebreaks, equipment and personnel requirements,

preferred ranges for weather parameters, a narrative describing how the burn will be

conducted, contingency plans, and emergency contact information.

Personal safety is the most important consideration for a prescribed burn. Anyone

assisting with a burn should wear all-cotton or wool clothing from head to foot.

Cotton clothing will ignite, but not as quickly as other materials and synthetics tend

to melt on to your skin. Dressing in layers provides the option of cooling down

when working close to the fire and staying warm when working away from the fire.

Leather shoes or boots provide good support and do not ignite easily; and a hat is

recommended to avoid singing your hair.

CERA has recently acquired personal safety gear including 4 Nomex, fire-resistant

suits, 5 helmets with neck and face guards, and several pairs of leather gloves with

long wrist bands. The helmets are comfortable and are fairly effective at keeping

smoke out of your eyes, nose, and mouth. Safety glasses, a hat, and a bandana can

be used in place of a helmet. If you assist the burn crew, we will provide a helmet

and gloves and fire suit if one is available.

For the actual burn, a drip-torch or flame torch is used to start the fire. However, a

few matches can be used in combination with a steel rake to spread the fire line.

The torches use a combination of diesel fuel and kerosene.

Backpack water tanks are an absolute necessity for prescribed burning. They hold

about 5 gallons of water and have a slide–action pump that can shoot water several

feet. Full tanks weigh about 50 lbs. The tanks can either be carried or placed at

intervals along firebreaks for emergency use. We now have collapsible tanks that

can hold about 4 gallons and are more comfortable to use for longer periods of time.

In addition to the backpack tanks, we also have a 300-gal tank that’s mounted in the

back of a pick-up truck with a gas-powered pump and 1+” diameter hose. The tank

is used to water down firebreaks, especially between experimental plots, and for

emergency situations where fire has crept across a firebreak or a spot-fire has

ignited. It can also be used to re-fill backpack tanks.

Of these 5 weather parameters, relative humidity is by far the most important. It

reflects how much moisture is in the air, as well as in the vegetation. The lower the

%RH, the lower the absolute amount of moisture in the air. At lower %RH, less

than 60%, the drier air absorbs moisture from the vegetation. Drier vegetation

ignites quickly, and burns faster and hotter. At higher RH, the vegetation may not

ignite at all.

The preferred range for controlled burning is 25-60% RH. Above 50%, higher wind

speeds may be necessary to drive the fire into the vegetation. Some of the energy

from the fire is used to dry the vegetation before it’ll ignite.

Relative humidity is generally lowest during the middle of the day, between 2-5

p.m.

As a minimum, a Prescribed Burn Plan will include:

• Map indicating the location of the burn. • Resource management objectives and timing of the burn. • Pre-burn vegetative description of the area. • Acceptable conditions for prescribed burn. • Description of pre-burn preparation. • Description of the firing technique to be used. • Equipment /personnel/safety requirements. • Special precaution areas.

What is Patch Burn Grazing? Patch burn grazing is defined as the application of prescribed fire to focus livestock grazing on a portion of a single grazing unit where the objective is to increase the diversity and structure of the vegetation in a way to benefit wildlife and maintain livestock production. Patch burn grazing is a grassland management practice for landowners primarily interested in improving habitat for wildlife while still maintaining cattle production on their land. This management practice creates a mosaic of heavily grazed and lightly grazed areas that provide a diverse vegetative structure and increase plant diversity in the same grazing unit. From a livestock production perspective, reports from research in Kansas and Oklahoma are showing that patch burn grazing is producing weight gains competitive with cattle raised under traditional grazing management in the Flint Hills. Year 1 Year 2 Year 3 This simple illustration shows how a patch burn grazing plan is divided into three burn units (shaded area). During each grazing season, animals will access the entire paddock. Grazing intensity will be higher on the burned area because of improved palatability due to managed fire.

Prescribed Burning

A Critical Habitat Restoration Tool

• What is done to prepare for a burn?

• What equipment is used?

• How do we decide when to burn

• How is a burn conducted