Sunday, 21 January 2018

Great Brush Pile Burning

Author with leaf blower brush pile burning in the background.

There is more to burning a brush pile than dousing it with gasoline and throwing a match at it.

Mid winter is a great time for brush piles burning in Wisconsin. My wife Anette and I unpack the Forrester: first the sled; then the leaf blower, pump sprayer and torch fuel. Fill the chainsaw with gas and bar oil. No need to bring along extra as the saw will see limited work today. Some snacks, tea and juice will keep us happy through the upcoming afternoon. Finally, I tuck some dry kindling and a roll of old construction prints what will be our starter.

A mid January thaw during last week put the burn day in doubt. Forecast snow on Sunday night meant plenty of snow cover for the Martin Luther King holiday and our brush burning. A moderate snow, light winds and weather in the twenties meant we will be comfortable all afternoon.

The sled is half full and that is just fine with me. Anette grabs the rake closes up the car are we leave the county highway behind. The local snowmobile club came through this fall after harvest and dragged a beautify trail across the corn stubble. Access to the Vermont creek will be quick and smooth. I throw the rope across my shoulder and make fast work of getting to the easement.

Our first brush pile was made during two days work in early and late fall. The pile is made up almost entirely of honeysuckle and buckthorn with a couple small boxelders for good measure. The first task is blowing the snow off the pile and clearing a small ring around the pile.

It takes one calorie to raise the temperature of one pound of liquid water one degree Fahrenheit. To melt that same pound of ice to liquid water requires 36,150 calories of heat. To take that pound of water from 32 degrees to its boiling point requires a mere 180 calories of heat. However, to boil off that heat and drive it out from soaking wet wood require a colossal 241,765 calories. This is called the latent heat of melting and the latent heat of evaporation.

That frozen wet wood on my burn pile needs to thaw out heat up and drive off its water, then continue up to the 700 degrees needed for wood to Ignite. Now consider that there is a cold wind trying to carry off the precious heat from my fire. No wonder it is so hard to get a brush pile to burn in the dead of winter.

Blowing the snow from the pile and around it suddenly makes a lot of sense. So does bringing along paper and dry kindling. These will make sure I have fuel that can easily light and stay burning long enough to dry our surrounding wood in the pile.

Torch fuel is a two to one mix of diesel fuel and gasoline. Diesel has a low ignition point but a high flash point which makes it much safer to work with than straight gasoline.

A wise friend finally put me straight about using accelerants on brush piles. “You don’t want the torch fuel to burn. You want the torch fuel to make the wood burn. Let it set there for ten minutes and see what difference it makes.” He was right! All my life I would pour fuel on a pile and light it, never understanding that the fuel was sitting on top of the wood and burning itself off without heating up the wood enough to get it to ignite.

Now I pour on a quart where I would have used a gallon. By walking away for ten of fifteen minutes, the diesel has time to soak into the wood. There is no big whoosh of flame, instead the dry kindling and paper take off and heat up the surrounding wood that is ready and raring to burn.

Snow on the ground means embers will not ignite surrounding vegetation, making it safe for a couple of people to burn several piles at once. Many towns are weary of issuing burn permits in the spring and fall when dry grass and leaves make spot fires from brush piles a real danger. Winter burn permits are easy to get and are easy to watch.

Anette keeps vigil using the rake to push remaining branches from the edges into the coals where they are quickly consumed.

I head upstream to a downed tree that needs to be cut and stacked. It takes a half hour to get the pile set, but because this is a black walnut that is not yet finished drying out, our efforts to burn the pile meet frustration. After several failed attempts, it is time to move on to a third pile.

Like the first pile this is one has plenty of honeysuckle, which burns easily, buckthorn that burns okay when dry and preheated, and boxelder that has laid there for several years. As this large tightly packed pile springs to life, Anette breaks out cookies, chocolate hot tea. The snow is flying all around; we relax and enjoy the now fading sun as it forces itself through the snow and cloud cover.

As the sun begins to fade, I once again take out the leaf blower. There is a large bed of coals and large sections of trunk burning in the middle of the fire. There remains plenty of brush around the downwind edge of the pile that I am in a hurry to dispatch. Braving the smoke, I rake the remaining unburned fuel into the hot center where it sits listlessly. The small pile seems to be waiting for an invitation to burn.

So I supply just such an invitation. My leaf blower comes out of the sled and springs to life. Its supercharges stream of air turns the bed of coals into a blazing forge. The coals become furious and through intense flames and heat that make short work of the remaining branches that threatened moment earlier to suffocate the those same coals.

A few minutes running around the edge of the fire with the leaf blower moves the mixture of snow, leaves and twigs at the margin out into the snowy barren reaches beyond. A wide patch of charcoal black mineral soil now separates the two worlds and provides a safe barrier for the remaining wood to finish consuming itself.

We pull back across the field and wipe off the snow from the bottom of the sled. It slides into the back of the Subaru as the last rays of sunlight fade.

 

2017

March 2017

Sunday, 26 March 2017

Get Fired Up

Crew checking backpack pump cans

Crew members check out backpack pumps before the pre-burn briefing. Crews take care to make sure everything is working right because depend on their equipment to keep them safe.

It’s that time of year again; time to get the burn gear ready to go. An early thaw has brought the spring burn season by several weeks. Though this weekend has been a washout, crews were already in the field last week and will be heading out again as soon as the fields and woodlands dry out.

A number of non-profit organizations conduct controlled burns across Wisconsin. While they typically only work either on public lands or property that they manage, volunteering as a burn crew member with them is a great way to gain the knowledge and skills needed to do controlled burns on your own land.

The Prairie Enthusiasts own or manage several thousand acres across southern and southwestern Wisconsin. Burn crews work many afternoons and weekends throughout the spring until the green up of native plants and bird nesting brings the season to an end. For more information or to get on their burn crew email list contact Rich Henderson.

February 2017

Friday, 10 February 2017

Fired Up for Spring

Crew prepares for burn

The Nature Conservancy, the Wisconsin Department of Natural Resources and the US Fish and Wildlife Service are now accepting applications to attend their Spring Prescribed Fire Training Exchanges (WI-TREX). Applications must be completed by February 24, 2017.

These trainings are organized as an incident, using the Incident Command System. Participants will:

  • serve in qualified and trainee firefighting positions on a burn team
  • assist with preparing, scouting, briefing, igniting, holding, mop-up, and patrol on numerous controlled burns in the area
  • complete pre- and post-fire monitoring
  • train with various equipment
  • practice fireline leadership skills, and
  • learn about local fire ecology and management.

Email Eric Mark with the Nature Conservancy to register or to get more information .

2016

October 2016

Sunday, 16 October 2016

Why We Burn

Crew prepares for burnThe Illinois Prescribed Fire Council recently released a comprehensive report on the controlled burning state of that state. In its Illinois Fire Needs Assessment, the group details the reasons for prescribed burning, the number or acres currently being managed with fire, as well as the acreage that would benefit.

According to the report, only 1/8th of the needed acres are currently actively being managed with prescribed fire. Because of this, much of the habit acreage in Illinois is ecologically degrading. Approximately 20% of the current habitat acreage is so degraded that it will not currently support prescribed fire.

Rather than giving up the report makes specific recommendations that are relevant for private landowners and public land managers across the midwest. Among these are increasing public support for private landowners, in the form of training and mentorship so that they have the knowledge and skills needed to manage their property.

For more information on prescribed burning check out the Illinois Nature Conservancy prescribed fire FAQ page.

March 2016

Saturday, 26 March 2016

Opening Day

Sunday was the first day of burn season. Okay, it was the first day of burn season for me. The truth is my fellow burn buddies in The Prairie Enthusiasts started without me on Friday. Worse, because many of them are retired, they will be burning on Monday and Tuesday while I am punching a time clock.

Burn season is that magical time in early spring between winter brush season and fishing season. Throughout the winter, on days when the weather permits, chainsaws, brush saws and loppers reclaim neglected southern Wisconsin shrub-land to a semblance of the prairie and savanna that settlers found when the arrived nearly two hundred years ago. Brush clearing drives away the winter doldrums, but it is fire that makes the magic.

Fire from prescribed burns is needed to keep the invasive shrubs and aggressive trees like boxelder and black locust at bay. Most trees and shrubs do hot tolerate fire. Their bark burns and the sap layers beneath are destroyed, killing the woody plants. Some trees and a very few shrubs tolerate fire. For millennia, bur oaks, white oaks and hickory have used their tough bark to protect them.

Before European settlement, lighting and fires set by Native Americans keep the prairies and savannas of southern Wisconsin clear. Today, that task falls to public land managers, private landowners and volunteer groups like the Pheasants Forever, Quail Society, Prairie Enthusiasts and Nature Conservancy.

We meet up at the barn at noon and within a half hour a dozen hearty soles are at the first burn unit getting our briefing. Weather is perfect, northwest winds 10-15 mph with relative humidity in the mid 40s means the fire will be manageable, even on the steep slope that makes up our first unit.

A pair of sandhill cranes move off the marsh scared by the commotion of a dozen humans even before flames light up the hillside. They are just beginning their nest building and have not begun laying eggs. Enough unburnt spots will remain in the marsh for them to rebuild a nest in time to raise their family.

The burns continue through the afternoon, right up to sunset. We burn two upland hillside units and a third large marsh area, which has six test wells that must be protected from the flames. All goes according to plan, with the final fire line being closed off as the sun set over the ridge.

Most days I keep my Nomex hood pulled up over my cheeks and nose to protect them from the flames. Today, however, it is the chill wind that keeps my face covered, especially as our crew is forced to wait to light off the upwind side of the marsh unit.

With luck, burn season will continue until Mother’s Day weekend and opening day of fishing season. For everything there truly is a season and a time to every purpose. Helping to restore balance to the land is what conservation is all about and looking over that valley ready for its spring rebirth makes me feel blessed.