Final burn of the year?

Despite our successful burns, we still had two more areas to burn. Unfortunately, burn conditions this past week were "too" good, with very low humidities, and all burns were canceled by DNR. Finally, on Saturday morning the humidity was a bit up and predictions were for afternoon rain, so we received permission to go ahead. Unfortunately, everyone else in southern Wisconsin was also burning, so there were only four of us to do the burn. But the burn went very well.

The area we wanted to burn, Units 20 and 21, are an interesting combination of open prairie, savanna, and closed oak woodland. They had been restored about 5 years ago with the removal of lots of black walnuts as well as elm and cherry. Former walnut zones are hard to restore because the trees produce juglone, a chemical toxin that inhibits lots of native species. However, brambles are not inhibited, so both areas had become heavily infested with black raspberries. The best method of eradicating brambles is to run a hot fire through to top kill the plants and then spray all the resprouts with triclopyr (Garlon). So we really needed to get this burn done.

The photo at top shows the Unit 20 burn in its later stages. The unburned area in the foreground is the Pocket Prairie, which we had burned late last fall. As can be seen, the burn coverage was very good. This is in contrast to last year's burn of this area, when the burn conditions were not so good and the coverage was much poorer. I attribute the better burn this year to the fact that the week of unusually low humidities had dried all the fuel out.

The fuel for a burn like this is primarily oak leaves, but there is usually lots of dead wood on the ground which also burns, as can be seen in the photo at left. If burning wood like this is well inside the burn unit, we do not put it out, but leave it to burn up. Depending on the conditions in the woods, this may take a few hours or overnight. Rarely is the wood completely consumed, but the remaining wood makes good habitat for critters.

We try to protect all standing dead trees from fire by clearing around them, removing all vegetation with a brush cutter followed by a powerful leaf blower. However, we are not always successful here, and an occasional standing dead tree catches fire. The one in the photo below was heavily rotten and the fire was enough to weaken it completely. Fortunately, no one was using the service road when this tree came down!



This was a very successful burn, and we are looking forward to attacking the bramble resprouts as soon as they are large enough.

Thanks so much to Jim and Marci for spending part of their Saturday helping us on this burn. We could not have done it without them!