Tom's Blog

Monday, March 31, 2014

Challenging prairie/savanna burn in hill country

The weather finally cooperated and we were able to accomplish a large south-slope burn on Saturday March 29, 2014.  However, the burn did not go the way I had anticipated.

After a mild rain on Thursday the weather gradually cleared. Friday night the clouds vanished and Saturday dawned clear and sunny. By 10 AM, when we assembled for the burn, the humidity was about 50% and temperature 45 F. Our lush fuel, primarily little bluestem and Indian grass, quickly dried off.

Because the wind was out of the northeast, we had to completely change our plans. Fortunately, we had a large, experienced, crew (16 people), two pumper units, and plenty of water and drip torch fuel. We also had a good Kenwood two-way radio for each person, so everyone knew what was going on. (Thanks to Rich Henderson and Chris Kirkpatrick of The Prairie Enthusiasts for handling the FCC authorization on these radios.)

We have burned this steep hill many times but this was the first time we had to start at the opposite end of the ridge. Lighting started at the top, at what we call the Far Overlook, backburning down the hill. The line moving west started down the ridge almost immediately, and had the west end tied off very soon. The long line moving east took much longer.

Backburning down the south slope at the start of the west-moving line.

Half way along the long east line, backburning through a prairie remnant lush with tall Indian grass. Lots of water was needed here to keep the fire from creeping into the savannas above.

Near the end of the long east line. Denny's Polaris ATV was able to navigate the rather tricky side slope of the fire break at the top of the hill. Kathie ran the  Kawasaki Mule with pumper unit (see photo below).

At the east end of the ridge it was necessary to tie off the burn unit adjacent to the Basin Savanna. Kathie backed up the hill along the break so that the hose of the pumper could wetline the whole break. In addition, six crew members had water backcans to take care of any spot fires.
Amanda lighting. To speed  up the burn, several drip torches lighted below the upper fire line once a good blackline had been created at the top. Photo by Michael Vahldieck

View of the south slope from Pleasant Valley Road. Since most of the slope was now black, a headfire was used to complete the burn. (Photo by Michael Vahldieck)
Although most of the fuel was warm-season grasses, the areas under the bur oaks near the top of the hill were too shady for grasses. Although the sun had dried them off, they burned in typical savanna fashion as a slowly moving line of ankle-height flame. Thus, the burn crew had to contend with alternating areas of high and low flames.

The whole burn, 15 acres, took 2 hours to complete. After lunch we burned 10 acres of planted prairies.


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