Thread: Minimizing fire damage

Hi guys,

Any tips for protecting trees from fire damage?

At our building site, we've bulldozed about 5 acres of almost mature forest into 2 very large, nicely packed slash/burn piles. The small one (about 100ft x 50ft) has a couple of real nice dogwoods and small (3" dia) beech trees around the pile that I'd like to try to save when we do the burns. The keepers at the closest points are about 20 ft from the piles. I HOPE to try to burn the piles "surgically", keeping the major heat just in the center, and push the ends into the center as it burns. This may not go quite like I'm hoping! The piles have now been drying for about 8 weeks, and I figure I need to wait until after the first good freeze so the keepers will be dormant, so probably another 6-8 weeks until burn time. I have good water supply, so I can saturate the roots good before and during the burn. Anything else I can do?

- Jay

You can go in and trim the piles with a saw around your keeper trees and pull that fuel further back into the center of the piles. You can also keep your hose handy and wet the pile itself in the spots where your keeper trees are to slow the burn rate and reduce radiant heat.

The main problems with these piles to your keepers is radiant heat and potential to scorch the root beds. Building such large piles may be efficient to the builders, but it's a horrible way to dispose of slash. The soil underneath these piles is going to be sterilized and unsuitable for growing anything but weeds for a long time after these piles are burned.

I'm trying to wrap my brain around bulldozing 5 acres, but perhaps that came out differently than you actually meant.

If you are clearing an area for building, renting a chipper and producing mulch to put back into the ground would have been an excellent choice. Saving anything for firewood would have been an excellent choice.

Jacob's statements about radiant heat and root scorching are spot on. If you can stand in front of your keeper trees and not get uncomfortable they will probably be ok...but that still may not mean their root zones will not suffer.

Sylvia

I agree with Sylvia on this one when it comes to mulch and firewood. In this area developers are not allowed to burn there waste from clearing operations. They either use a Gyro Trac, which is a big mower which pulverizes the debris or grind it up and haul away the chips but no burning.

20' from a 100' by 50' pile is not nearly enough. Your dogwoods will be scorched, and the root zones will be damaged. Unless you have a water curtain set up between the fire and trees, and have another hose to keep the foliage and ground wet as you burn, they've got little chance of survival. I've seen the radiant heat from a fire melt vinyl siding over 100' away.

Dogwood and beech are among the most sensitive species to heat. If you cut everything else out around them, these trees will be stressed enough by sunlight. Keep fire way away, or better yet process the debris into mulch.

a 6" layer of mulch around these guys until construction is complete would be a good idea.

What does the arborist who developed your tree protection plan say?

Hi folks,

Thanks for the tips!

I will try the water curtain to the degree possible, but it sounds like there's not much else I can do!

The 5 ac IS right! It consists of about 3 1/2 acres of field/pasture and the rest for the home site plus a 400' back driveway. This is agricultural land VERY isolated from any other property, so most clearing restrictions were NA.

The piles are mostly hickory and pine. To save any of it for firewood would have meant a huge increase in the time ($) needed and someplace to store it all. It was all dozed and piled in about 20 hours of dozer time. The speed and efficiency of a skilled dozer operator is just an amazing thing!

Firewood is so plentiful around here, we haven't even been able to give away the slash from cutting in the powerlines, even after we bucked and stacked it!!

It was way too much to chip. I considered hiring in a tub grinder, but the cost was prohibitive. So burning is the only remaining option.

- Jay

Originally Posted by JRobyn

The speed and efficiency of a skilled dozer operator is just an amazing thing!

Yes, and they are also remarkably efficient at killing the shallow root systems of beech and dogwood.

You need to mulch them yesterday. Posting pictures would help us on the rest.

Here's the "little" pile which has the keepers around it.

Here's the big pile - not too much of an issue with that, because there's nothing within about 150 ft of it at the closest.

You will toast those dogwoods if you burn that close to them. Why not move the piles and if they were piled up with a bulldozer then there will be a ton of dirt on those piles and it will take awhile for those piles to burn. Another suggestion is to burn the piles in a couple of months when the trees are in dormancy which might help there surviving the fire.

Next time hire someone that actually specializes in land clearing, most people with bulldozers won't and don't touch brush, that pile should have been burned as they went and never got that big in the first place, if you''ve already burned it what are you doing with the stumps that didn't burn, the pile is too big and spread out to burn 100% and the stumps should have been cut off and placed on top, the dirt in and shoved up all around the pile will need to be respread and sifted all the sticks out of it, if you wanted those trees saved you should have eliminated the problem and told them to burn it as they went and never got close enough to harm the trees, if you came onto the scene after the best approach is to hire someone else and repile the pile somewhere next to it smaller and burn the whole thing and level off their nightmarish mess when its done. The reason you have the mess is because they didn't want to step down out of their heated airconditoned cab and actually run a chiansaw or pick up sticks, I see it every day and specialize in cleaning up others messes and deal with land clearing unwanted and saving wanted trees every day.