Tuesday, February 13, 2018

Prescribed Prairie Burning

Where CPH grew up, in semi-rural towns, a smoke cloud in the air meant one of three things. One: Near the outskirts and further into the countryside homeowners were busying themselves compiling the twigs, broken tree limbs, and leaves blown down from recent storms or strong winds and setting fire to them to dispose of the mass. Two: There was a house fire nearby. Or Three, determined by the color of the smoke: Some local was burning trash or tires in their backyard again... a sad but honest statement the last.

When we moved off to college near an industrious city, the smoke plumb evolved into a nuclear plant's steam release or the local factory stacks proclaiming it's industriousness.

Recently, Celtically Primal had the opportunity to be a part of a Forest Preserve's Burn Crew. At the end of the Burn Season, beginning February 29th ending April 5th of 2016, a plumb of smoke in the air acquired a whole new shift. Rather than speak directly on the benefits of using prescribed fire as both an efficient and cost effective tool to control invasives species and replenish much needed nutrients to the soils, as most blips about controlled burns go; CPH hopes to provide you, the reader, with an in-depth behind the scenes story from one who has personally worked the fire lines.

The story begins here at Resource Management Headquarters. It is here where members of the Resource Team discuss the current weather conditions: such as humidity, moisture on the ground, the possibility of rain, height of cloud deck, and the direction of wind. These factors determine where the burn of the day is to take place.

Of those factors, both wind direction and wind speed carry the majority of the decision. Wind speed is measured in knots, with one knot equating to one nautical mile per hour. Wind direction is shown by which point of the compass the wind is blowing from. For example a south wind blows from the south, NOT to the south.

Image Source: http://www.rya.org.uk/newsevents/enewsletters/inbrief/Pages/Measuringthewind

Given that a majority of the Forest Preserves are backed by major roadways or subdivisions, attention and courtesy to the public is shown.  If the Preserve is bordered by a major highway, which is the case for more than a few of the preserves, the wind must be blowing from the same direction as the location of the roadway to the preserve. In Lyman's terms: If the preserve is bordered by a highway to the East, than an Eastern wind is necessary to safely burn at that location. 

Ya' see, wide scale burns produce lots and lots of thick, blinding, and choking smoke. On days when the cloud deck is low or when there is very little wind, the burn smoke, rather than rise, will hover and drift over the area resulting in near white out conditions. This is actually do to an invisible pressure in the atmosphere, as the close cloud deck pushes the smoke downward rather than being able to rise on full clear blue sky days. The potential for thick, white-out smoke increase as the season stretches onward into bloom and the grass begins to green.


Meanwhile back at HQ...

Once a location has been decided upon, the crew begins to gather equipment while completing an extensive daily prep and check-off list. Day one found the acquisition of personal safety gear to wear during the burn. The suit, while not fireman grade, is still flame retardant and helps slow down and even block heat transfer to the wearer's body.  The yellow helmet not only protects the hair on one's head from the stray floating ash ember, but the thick plastic face shield and flame retardant coif deters the heat from ones face and protects the wearer from the multi-flora rose and bramble thorn thickets traversed while dripping. (An explanation of that term to come.) The kit completes with thick fire retardant gloves, a breath mask with filter, and a chest harness to strap walkies-talkies on our person, this allows for greater communication between teams on opposite sides of the burn unit.  

These well loved and used canisters pictured below are known as Drip Torches. Every morning and even a few times in the field the torches are topped of with a 50/50 ratio diesel to gas burn mix. The Central Resource Shop operates on four drip torches and two 4Gal yellow metal gas cans. The plastic canisters, as learned through trail and error, have a tendency to melt when exposed to the high heat of a burn for too long and may have resulted with the back of someone's Gator (water rig) on fire. Having not been around during this era, this was not directly witnessed, but it sure does make for an interesting spectacle in the imagination and reminds the humble man that this job is in fact dangerous. 

The canister comes equip with two valves. The metal knob in the foreground controls the air flow into the canister, while the larger knob in the background labeled "flow" controls the rate in which accelerant flows from the metal wand.  

The head of the wand itself consists of a piece of mesh boxed in on three sides. This creates a pool of accelerant and fumes that once lit will drip liquid fire at a controlled rate from the head.

The vehicles below are truly the backbone of the Forest Preserve's Natural Resource Department. We cannot count the number of times these machines have come in handy for various projects in the field. Burn Season is no different. Equip with a 50Gal water storage tank, a hundred feet of hose, attached to a pressurized spray nozzle, powered by a small motor; the Gators (as named by John Deere) are transformed into mini mobile fire-fighting rigs.

 The Gators themselves also have an extensive check and prep list. 
  1. Before the Gator leaves the garage, all four tires are inspected for proper pressure, at 25lbs, and for any leaks acquired from the previous days work or a loose plug. Any flats are inflated and leaks plugged with a plugging kit that consists of strips of spare rubber, rubber cement, and a specialized tool that you jam into the tire hole. The plug kit, a traveling air tank, a spare tire, a jack, and a socket set are also loaded into the truck as a a backup plan in case the Gator blows a plug or acquires a new hole throughout the days rough travel.  
  2. The Gator is blown down with pressurized air dislodging any spare bits of dried prairie grass and twigs hiding under the chassis adding potential insult to injury via fire hazard.   
  3. The air filter is taken out and aired daily to remove the extra smoke particles that built up during the previous day.
  4. The motor that controls the pressurized water pump is filled to full with straight gasoline and a spare 1Gal can is loaded to the truck to function as back up. The motor is started to ensure all functions properly before departing for the field.
  5. The secondary tank is filled to be used sparingly with Class A Fire Foam, as pictured below.
  6. Lastly the Gator is topped off with diesel to be sure the department gets a full days use out of the machine.

While the actual price of this foam barrel eludes me, I will just say that it is not cheap and that it is very effective at deterring fire once sprayed on various objects. Some individuals have been known to use straight soap to achieve relatively the same effect. (More details on the effectiveness of said fire foam to come in time.)

Finally the 50Gal storage tank is filled to the brim with water ready to save the any area of land or tree burnt out (<-- Pun) from combating too much fire and heat.

Once the check list is complete and all things are a go, the Gators are mounted in tandem on a trailer between two heavy duty ratchet straps a piece to ensure maximum safety during transport. 

This 500Gal tank below is also filled with additional water and trailered to site in case the heat of the days fire blew through the tanks initial reserve. This tank also has a motor that powers a pump that needs to be topped off with gasoline before heading to the field. 

Once the burn crew arrives to site, the water fleet is unloaded and ready to serve.


And So it Begins...

An unsuspecting dawn arises regardless of the drastic change ahead.

The burn is put on hold until the morning dew has a chance to evaporate from the tall grass laid over from this Winter's snowfall and ice-pack. 

As we wait, signs of spring are making themselves known reminding the resource team that the burn window is incredibly narrow.

Grass is greening up out of a dry dead brown, while Red-Winged Black Birds clang away expressing territorial rights over sections of tall grass.

Given that the season is early yet, this is concluded as last season nest and there is little worry over burning finds like this up when the head fire rolls through.

A few more before photos of the unsuspecting field before all fire breaks loose.

The image below is actually of a heavily populated section of land that is slowly becoming overcome by blown in Willow seeds from the tree line near the river to the right of this image. There is a significant bare spot to the immediate right of the Willow stand. This was mowed over and created with purpose last Fall to serve as a fire break. (More about them further into the story.)

Members of the Burn Crew prepped in Turn Out gear discuss the best way to achieve the most effective burn while keeping all hazards low. This seasons Burn Crew maxed out as seven individuals, most commonly operated at or above five but also functioned as a four man crew during the closing days.

With a very basic plan formed, the crew splits into smaller teams and begins to light up. Most commonly this division goes: one dripper to one gunner, but has been known to double up on gunners at larger burn sites where more valuable trees need to have extra protection.

A test patch of grass is lit to ensure enough of the morning's dew has evaporated to make for an effective burn.

On more than one occasion during cooler burn days, the crew would gather around the test burn to ward off the chill of the morning before motion provided the body with natural heat.

Should the test burn function correctly, the crew heads out to the Fire Breaks or Areas of Concern to prep for and start fires.

I found it kind of ironic when I first joined Burn Crew that in order to ensure an area stays untouched by fire, one must start a fire immediately next to it. Having now worked with fire as a tool to control invasives, the science behind why this works totally checks out and will be explained in the next few photos.

 The short clip below shows the ease at which a prairie fire is started if exposed to a high fuel source.


In the case of this burn, the crew wanted to limit how much fire the trees received. So, naturally, a wall of fire was lit with a 7-10 foot buffer in front of the wall of trees. Given little to no wind, this allows for the slow progression of fire in either direction. The fire burns backwards from the line of ignition spreading through to the nearest fuel source. The fire line that takes off towards the intended area of burn is left to propagate on as a Back Burn, while the opposite line of fire nearest to the trees or plants of concern are extinguished by the water fleet, or dissipates when contact is made with a pre-foamed break line.  This ensures a proper black out area that will act as a safety buffer were the wind to change mid burn. It is named Black Out given that the fuel source has been reduced to black ash and no longer hosts any additional burn fuel. 

Math, particularly Angles, surprisingly come into play and influences a burn more than I ever fathomed beforehand. The angle of fire can help to establish an effective fire break observed around and in between trees. If used correctly with the wind, cutting the fire at different angles have even been known to draw fire, particularly smoke, away from an undesirable area such as a road. The difference in heat creates a difference in pressure which draws air mass into the void; and in this case the air just happens to be filled with smoke. The effectiveness of this greatly depends on wind direction and speed, but has been known to work in the right circumstances.  

Thus far we have followed the Fire Dripper, the individual who traverses the land by foot setting fire to anywhere they walks with a torch tilted towards the ground. Moving onto the Gunner position; the Gunner is responsible for the safe keeping of fire intolerant trees as well as policing and deterring any fire that has back burned too far past the fire break.  

This little Ceder tree, were it not pre-foamed would have little to no chance standing up to the thick and tall flames of fire; even if it is just passing through.

A liberal amount of foam is allocate around every object of concern. 

The ratio of application varies dependent on how much surrounding fuel is nearby vs. how valuable or fire resistant the object naturally is. Telephone poles, wooden birdhouses, fiberglass sign posts, and heat intolerant trees such as most the Oak family, Sycamores, and any other tubed or planted tree make up a majority of the foam targets. 

Once pre-foam is in place, the Gunner switches back to water only (done by rotating the nozzle) and begins to police the backline. 

Fire is both predictable and unpredictable. Predictability based on the principle of if there is fuel, a source of ignition, and a little bit of oxygen, the fire will travel where the fuel load can be sustained. Fire's unpredictability comes from its exposure to wind and the ability to hid hot spots of extra fuel buried under the quick to burn blackened top layer.  

Given enough of a strong and sustained wind gust, the fire has been known to spontaneously change direction and jump the fire break. The photo below would be a good illustration of a fire jump were the crew not intentionally setting fire to both sides of this path.

A brief photo dump of Fire Break shots are to follow. 

With such a limited crew, it is vital that all fire breaks are well established and extinguished with a black out buffer of at least 20 feet before the go ahead is given to lite a head fire.

It is not always done like this, but occasionally the situation arises where one can Run n' Gun. In the correct conditions (i.e. ratio of fuel load to humidity is cooperating) the most time effective way to light a head fire along a path is to Drip and Drive. If both those terms cease to describe the situation correctly, this is where fuel is leaked from a torch while the trusty Gator-Steed carries the liquid fuel along at a hastened pace.

Again, once safety conditions are met, this method is an effective time saver allowing one individual to set fire to a quarter mile of land in under a minute. Go Gator Go!  

These next two images are some of the realities of using fire as the most cost effective tool to control invasives. Simply put, habitat is temporally lost. Tiny mammals like mice and rabbits, whom of which use the dry shrubby grasslands as refuge, are forced to relocate; else they become easy prey for the circling hawk's lunch with no cover to hide under. 

Even the traveling deer herds are effected by the surprise of fire in what on average is a calm and quiet grassland. Both the deer and rabbit were witnessed evading the wall of flame, both groups arising victorious from the surprise survival of the fittest encounter. While it may seem inhumane to effect wrong place wrong time mammals, it is good to remember that fire was a naturally occurring thing of the past, only recently down-scaled to human development.

It would probably be good to mention that no reptilian species have yet to be sighted above the ground at this time. Their emergence is a reminder of just how tight and narrow the burn season is. Once the weather shifts to the warm, reptiles are all too happy to wake and bake in the sunlight; something the Natural Resource Team has to consider. To work around this, the wetland prairies are avoided on warmer days. Now that the fauna has been spoken of, back to your regularly scheduled burn footage. 


 Mid-burn photo dump to follow... 

In all but a few seconds the wind can gust and the fire is fueled by literally a "breath of fresh air." The above and below photos were captured but a few seconds apart, the latter after a burst of air. Notice how much thicker the smoke looks alongside the fiercer fueled flames. 

This image captures how much heat is produced in the burn process. Notice how blurred the trees look on the left half of the image verses the right portion below. This begs the unanswered question of: Does heat have mass? Lets jump into a small Physics lesson. If you consider heat energy the kinetic energy i.e. energy as result of motion/friction of the molecules then no, the amount is negligible. But heat can also be in the form of electromagnetic waves i.e. light. (What we are "seeing" below.) So again it becomes complicated to decide whether it has mass or not, and remains an unanswered mystery of science. 

At the beginning of a burn, both crews are running around starting and putting out fires. Once all four sides of a larger burn unit are lit, policed, and confirmed Black Out areas; the crew need just sit back and enjoy the efficiency of invasive control in this type of setting.  

With so much a lite at once, the noisy crackle and blasting heat of the fire is almost overwhelming and most defiantly humbling.

Let the fires rage onward until the fuel source is engulfed in one last blast of thick hot flames.

And the Mid-Burn Photo dump continue...

The below image is one of my favorite captures of the Burn Season thus far. High winds were gusting and pushed this fire line upwards in a westward whirl.  

Here is some Physics talk again... Brace yourselves...

Fire is scientifically described as: A rapid, persistent chemical change that releases heat and light and is accompanied by flame, especially the exothermic oxidation of a combustible substance. At a certain point in the combustion reaction, called the ignition point, flames are produced. The flame is Layman-ly described as the visible portion of the fire. Flames consist primarily of carbon dioxide, water vapor, oxygen and nitrogen. Depending on the substances alight, and any impurities outside, the color of the flame and the fire's intensity will be different.

End Physics. 

While policing one of the back lines in Oak Ridge Forest Preserve this tree, which was immediately nicknamed, "The Burning Bush," was sighted. Given the clean cut trunk and the relative size of the tree with no other signs of coniferous (needled evergreens) trees in sight, this was concluded to be a discarded Christmas tree. Not an uncommon find we are told. This tree burned start to finish, no joke, under 20 seconds. I love how this shot captures the whole process all in one fell capture: The dead and dry needles can do nothing but disintegrate before ones eyes as the resultant ash is blown away by the wind on the opposing side.

As one of the four elements, fire has mixed symbolism because it represents energy, in which the application of fire is a prime method of conversion, and everything that touches fire is changed, often beyond recognition. This can be both helpful when controlled, but volatile if left unchecked.

It should be mentioned that a slower propagating back burn is more effective at removing unwanted vegetation than its hot and hasty head fire opposite. A head fire is fueled by the wind and propagates quickly at the expense of burning through the top layer of fuel while not having the time to heat up and ignite the thicker forbes as a slower back burn would have.

The Smoke Rolls On...

As the fire burns through (<--another pun) the fuel store, the land is left almost barren, save for the few stems thick enough to resist the heat of the head fire.

The photos to follow aim to capture the dynamic beauty of the massive smoke plumbs. It is honestly humbling to stand next to something so vast.

In the photo above there is what looks like a tiny mound in the center of the black out horizon-line. That bump is actually a Gunner on a Gator, for scale.

A short clip to illustrate how wind can influence the smoke deck, and in this case, even temporally block out the sun. 

Another of my favorite shots in this unit. So simple. A Man, A Gator, and a wall of smoke.

However, if you look with more detailed eyes one can see mounds in the ash barren field. These mounds are actually giant ant hills.

Another series of photos (above and below) that show the effect just 15-20 seconds can have at a burn sight with decent wind.

As the fire dies away the Gunner and Drippers pair back up to assess the effectiveness of the burn. The burn unit's borders are traversed all while keeping an eye out for hot pockets and tree fires.  

A brief capture of the immediate after burn. The land at this stage reminds me almost of a volcanic setting. Hot pockets of unused fuel smolder under the blackened top layer. The color of the burn shifts drastically at this point from a hot fiery reddish-orange to a cooler blue-gray smolder all within a few minutes time.  


While the goal of a burn is to maximize the area of black out, patches of grass that escape the burn act as sanctuary for any insects able to escape the fiery wall.  

The reality behind the type of grass usually spared from the fire is a far more in-depth tale CPH will have to save for a plog about Invasive Species. There is much to say about the Reed Canary grass spared by loving the low-laying water saturated areas, but alas a tale for another day. Back to assessing the black out.

For those who have never seen the aftermath of a controlled burn, it may appear shocking at first. A blackened and smoking landscape greets the eye, and it appears as if all life has been destroyed. The reality is far different.

Ash returns nutrients from plants back into the soil, especially calcium, potassium and phosphorous. Nitrogen is returned by the nitrogen-fixing plants that flourish after a fire and begin the process of regrowth. Without nitrogen, proteins cannot be made, and DNA cannot be reproduced. Most of the earth's nitrogen is in the air, but can’t be breathed in. Nitrogen-fixers host bacteria in their roots which convert atmospheric nitrogen into a form plants and animals can use.

 The two photos above are actually of the same area, the second a close up allow one to see what remains of the Clump Grass stands. These types of grasses obtain their names because they propagate and grow in clumps.

A tiny Ceder tree is damaged as the fires wall breaks through its tiny defense barrier. If the full tale were to be told for this tree, is that is was probably overlooked in the initial pre-foaming or it was foamed too early before fire made contact with its thin layer of defense. My money is on the former. 

There are also those trees whom don't need any pre-foaming at all and are naturally fire resistant all on their own. They will make a full recovery, this dark is more of a tan for them and will exfoliate off in time just as human skin does.

A Windy Vortex... or Four 


A whirlwind is a weather phenomenon in which a vertically oriented rotating column of air forms due to instabilities and turbulence created by heating and air flow gradients. This causes a funnel to form. The funnel moves over the ground, pushed by the winds that first formed it. The funnel picks up materials such as dust, snow, or in this case ash as it moves over the ground, thus becoming visible.

Minor whirlwinds are not as long-lived; the winds that form them do not last long, and when a minor whirlwind encounters an obstruction (a building, house, tree, etc.) its rotation is interrupted, as is the windflow into it, causing it to dissipate.

Switching topics a bit lets talk about ash again. Ash or Ashes are the solid remains after something is burned. Ashes as the end product of incomplete combustion will most likely be mineral, but usually will still contain a small amount of combustible organic residue. Assumedly, the most well-known type of ash is wood ash, as a product of wood combustion in both campfires and fireplaces. The darker the wood ashes, the higher the content of remaining charcoal will be due to incomplete combustion. Grasses, on the other hand, are so thin that the ash flakes produced by the fire will float with minimal coercion due to its relatively low to none existent mass.

Fire and Wind are both dynamic forces of nature. When the two dance the result is beautiful. The following four images capture that dance.

Even though there is fire in the vortex's core this does not jump classifications to become a fire whirl. The reason being: this is not a self sustaining vortex fueled solely from the combustible, carbon-rich gases released by burning vegetation on the ground. When this hypothetical fuel is sucked up by a whirl of air, the unburned carbon gas travels up the core until it reaches a region where there is enough fresh, heated oxygen to set it ablaze. This is just a whirlwind who just happened to bump shoulders with fire on the dance floor. 

Wrapping Up the Prairie


February 29th, 2016 marked the first day in the burn season. It was this day the lower field was set ablaze.

A time elapsed photo was taken on March 21st, 2016 for comparison. Already, in just 21 days one can see how the black out ash has began to grow back green. In just five more weeks, this land spot of land will be a booming metropolis of ideally native vegetation.  

CPH celebrated the opportunity to join this season's burn crew with a bit of a treat. As one who lives frugally by choice, mostly within the realm of barter, we allowed ourselves to invest in something brand new. Shzzam!!!!! Fresh Boots for the season! 

And here are those very same boots not 6 hours later.

This one hopes others draw motivation and impetus from this entry to get outside, explore, and capture those neat experiences with Nature. Until our next encounter. May the path be smooth and well lit. -CPH

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