Tom's Blog

Friday, October 31, 2014

Great woods burn Wednesday 29 Oct 2014

Choosing the right day for a fall burn is always tricky. If you burn too early, most of the leaves (the principal fuel) aren’t down yet. And if you burn too late you might have snow---as we did last night!  
Getting 19 people there for a burn and then having to send them home because conditions are not right is dispiriting. 

This year everything gelled. The bur oak leaves had come down in mid October, the whites about a week before we burned, and the reds three days before. There had been no significant rain so the leaves were dry. A dry air mass had come in on a cold front and held for several days.

We burned the whole north woods, about 30 acres, with an average burn coverage of 93-95%.

Burn crew gathering for final words before travelling to the fire line

Amanda and Susan designed the burn, put in the fire breaks, and handled all the details: water, drip torch fuel, equipment, etc.

White board with burn plan

We have burned the north woods quite a few times and they had the technique down pat. The whole burn unit is ringed by fire breaks. The North Fire Break at the top of the hill is the longest. It had to be mowed and cleared of leaves. The fire break on the west end is potentially tricky since it is next to the very flammable South Slope. Kathie and Willis used our pumper unit, positioned on PV Road, to wet line the hand-mowed fire break next to the South Slope. Several backpack waters were also involved as the fire line moved down the hill here. The east fire break connected the burn unit by ending at County F.

Near the west end of the burn. The savanna on the left will be burned in the spring

The North Fire Break with the fire line backing down the hill. Because of the good fuel, the fire backburned very well.

The procedure is to start lighting in the middle of the North Fire Break, with two burn lines moving in opposite directions. Because this is a long fire break, and is near rather flammable savannas, it takes a long time to get blackened in. Once this is in, and the two lines start down the steep hill at the east and west ends, interior lighting can begin. This year three strippers started at the east end and spread out, moving most of the way to the west end, where two other strippers were working. It turned out that the fire line from the North Fire Break backed over the ridge and started down the hill, so that the upper stripper could skip some areas.

We started lighting at 11:30 AM and the burn unit was tied off at 2:00 PM. The next hour was spent finishing the stripping, and lighting the County F road cut.

Here are several photos of interior lighting, taken by Michael Vahldieck (one of the interior lighters).
Looking toward the N fire break from inside the burn unit (Vahldieck photo)

Fire lines coalescing (Vahldieck photo)

Typical fuel, mostly red oak leaves. Note the low flame heights (Vahldieck photo)

Note the green shrubs, which are about to be killed by the fire. (Vahldiect photo)

In earlier years, the north woods burn has involved lots of mop-up, but this year only a single smoking snag was a problem and had to be cut down. There were, of course, quite a few smoking logs, but these were well inside the burn unit and were allowed to burn. It is our standard practice to leave smokers unless they are close to the edge of the burn unit. With a burn of this size, most of the smokers are quite safe.

The next day Amanda and Susan surveyed the whole burn unit. The average burn coverage was 93-95%.

The day after the burn. Oaks are not damaged by the fire, although it is hot enough to top-kill all the brush.
There were two areas that did not burn well. One was an area at the west end that had apparently been logged a long time ago. By the time we arrived on the scene, it was a tangle of honeysuckles. Although we have been dealing with the honeysuckles, since there are no trees there are no oak leaves to provide fuel. The other that only burned about 75% was at the NE corner. This was another area that had been logged many years ago, leaving only a few large red oaks on the property line.

In all, a great burn!


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