Efficacy of Whole Tree Harvest Thinning in Reducing Fire Severity

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Don’t ya love the black trunk scorching. Classic ponderosa. Color these photos black and white and you can step back in time 150 years ago. This was your pre-settlement forest. The Park retained a nice “clumpy” layout here.
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A more traditional spacing of 25 feet between trees. The 25′ spacing is the minimum to stop a crown fire. Don’t ya love that grass!

                            

The photos above were taken at Chadron State Park in the northwest corner of Nebraska. You couldn’t find a more warm/dry Ponderosa Pine habitat than this with annual precipitation of around 16 inches. As with most recreation areas in the West that sought to “preserve,” very little logging occurred in the last one hundred years (if any) and the average tree spacing was around 8-10’. I visited the park about 6 years ago right after the Park did a whole tree harvest thinning fuels treatment in anticipation of a wildfire just like the one that burned through last summer.

When looking at these photos, some would make the claim that this proves “fuels treatments don’t stop wildfires” and end their analysis there. But that ignores the fact that while 90% of the 1000 acre park burned, 80% of the forest is still green while 100% of the adjacent USFS lands is black having suffered a stand replacing crown fire. The “surface fire” in the Park was extinguished before it burned the 10% of the Park that contained 30 rental cabins, 80 camp sites, a lodge, picnic sites, and assorted infrastructure. Fuels treatments don’t stop fires, but that’s where firefighters stop them. The thinning in the park turned what would have been a stand replacing crown fire into nothing but an unscheduled prescribed fire. The thinning in the park turned what would have been a stand replacing crown fire into nothing but an unscheduled prescribed fire. But…but…but…of course, I suppose it “is” possible the Park survived because “the wind” just stopped blowing when the fire reached the section line dividing the Forest Service property from the Park.

Fuels treatments isn’t about “stopping the fire.” We’d have to pave it over to do that. Fuels treatments is about making it easier for firefighters to extinguish the fire but most importantly it’s about “what’s still green” after the fire. Because of the fuels treatments, a 70 year legacy of family reunions, weddings, and cool shady getaways on hot August weekends can now continue for generations to come. Every local, state, and federal recreation area in the West should be, and is, doing these kinds of fuels treatments. What better place to showcase the “efficacy of fuels treatment.” When the public sees these “green islands” in a sea of black untreated forests….they’re gonna wonder why the USFS didn’t do them everywhere.

 

The bottom two photos are examples of Whole Tree Harvesting. 

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Whole tree harvesting one week after logging. Note the light on the land touch and total absence of any “slash.” The bottom photo is one “day” after logging. Absolutely no slash or surface fuels. This stand was pre-commercially thinned 30 years ago and had a tree every 8 feet.Image
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The best kept secret of forestry is the “thinning release.” Thinning greatly increases the diameter growth rate of the remaining trees. This tree put on 7″ diameter growth in the 32 years since it was thinned in 1972, and about 10 times the cross section volume growth than in the first 46 years. In 20 years, the trees in Chadron Park will be 18-20″ diameter. A nice legacy for the next generation I’d say…considering the alternative.