Prescribed Burning in Minnesota

Minnesota Department of Natural Resources Podcasts
Prescribed Burning in Minnesota .mp3 (800 Kb) 03/26/09

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Steve Carroll:

Hi, everyone. I'm Steve Carroll, Information Officer with the Minnesota Department of Natural Resources and welcome to our program about prescribed burning.

My guest is Jean Bergerson, Information Officer for the Minnesota Interagency Fire Center, which is located in Grand Rapids.

Welcome, Jean.

Jean Bergerson:

Thank you.

SC:

Well, why do we prescribe burn?

JB:

We actually prescribe burn for a number of reasons. The reason that's kind of hit the media and been out in the forefront for the last few years is to reduce slash. And that's kind of a result of the Boundary Waters blowdown a number of years ago. They've been doing very carefully orchestrated prescribed burning up there to reduce that amount of slash on the ground.

There are also other reasons. We prescribe burn for habitat and particularly in the spring of the year we like to burn for sharp-tail grouse habitat. We also do some marsh burns to restore nutrients to some of the marshland for some of the waterfowl habitat. And we do restoration burns and that's done on two different kinds of habitat and it's done to reduce the understory in pine forests to allow them to regenerate. And most people are probably familiar with prairie burns. The traditional prairies always burnt from wild fire and now we're introducing fire to maintain those prairie ecosystems.

SC:

You mentioned slash. What does that mean?

JB:

Slash is material that's left on the ground – might be from logging, the residue that the loggers can't use, or in the case of the Boundary Waters it was obviously all the vegetative material, trees, and brush that went on the ground in that massive blowdown.

SC:

I see. Are there times of the year that they do these prescribed burns?

JB:

Yes, we do them in the spring and in the fall. Most of the habitat burns are done in the spring of the year. We do some of the hotter burns, like some of the slash burns, in the fall because in the fall of the year we'll be entering a season where the snow will be on the ground, the frost will be there, and if there's some hold-over heat in some of those piles that have been burnt it's not as apt to get up and turn into a problem fire when we do that burning in the fall. If we do it in the spring sometimes the brush piles decide to resurface when we get the first windy, warm day.

SC:

Is it true prescribed burns are not as hot and fast moving as wild fire?

JB:

Well, again that depends upon the type of burn it is. If we're trying to, for instance, take brush off of a habitat so that we can restore more of a grassy vegetation for sharp-tail grouse, we want that burn to be hotter and faster. Most of the slash burns, just because of the fuel, have a tendency to be hotter.

But each time a prescribed burn is planned there's a carefully orchestrated plan that's written. And that plan says what direction the wind should be, what temperature it should be, how dry the fuel should be, and what kind of specific conditions that burn should be conducted.

SC:

And then how do they go about containing the prescribed burn and only burn what you want to burn?

JB:

Well, there's a number of ways they do that. They might set down lines with mechanical tools, they might have a dozer or some sort of a mechanical piece of equipment that will actually put in a fire break, they may wet an area down, which is called a wet line, and do the same kind of a line but just by wetting it so the fire will not go across it. Also we sometimes use helicopters with buckets and we use what we call holding crews. And those are crews of individual firefighters that are standing there putting out any small fires that spot across the line.

SC:

Alright. Well, what kind of staff are we talking about and how much money are we looking at for a prescribed burn?

JB:

Well, again that depends on the burn - it depends on the size of the burn and the type of the burn. Some of the burns, like they've been doing in the Boundary Waters, can take place over the course several days. They're very complicated. There's a lot of aircraft, a lot of staff involved, but if you look at the tradeoff, another Boundary Waters fire, the cost is obviously significantly smaller and that's the reason for doing those.

The smaller prescribed burns, on a cost per acre basis, again the purpose is to restore habitat so we feel it's a beneficial way to do that.

SC:

Do only the fire managers burn?

JB:

Actually we have several other agencies in Minnesota. Although within the DNR the Division of Wildlife, the Division of Forestry, and the Division of Parks, and Eco Services all do prescribed burning.

But groups like the Nature Conservancy, which have a lot of our prairie lands around the state, have their own burning crews. And there are quite a few private contractors today that are hiring out to do burns either on private lands or for some of these other private companies like the Nature Conservancy.

SC:

OK, so it kind of depends on the project.

JB:

That's correct.

SC:

Alright. Well, that concludes our program on prescribed burning.

I want to thank our guest, Jean Bergerson from the Minnesota Interagency Fire Center in Grand Rapids for joining us.

JB:

Thank you.

SC:

And thank you for listening. I'm Steve Carroll with the Minnesota Department of Natural Resources.