Six et al paper on MPB Treatments, with Responses

Three related documents for study and discussion: A paper from the journal Forests, a response to the paper also published in Forests, and a white paper by a group of USFS Forest Health Protection folks.

Management for Mountain Pine Beetle Outbreak Suppression: Does Relevant Science Support Current Policy?” by Diana L. Six, Eric Biber, and Elisabeth Long, Forests 2014, 5, 103-133.

Abstract: While the use of timber harvests is generally accepted as an effective approach
to controlling bark beetles during outbreaks, in reality there has been a dearth of monitoring
to assess outcomes, and failures are often not reported. Additionally, few studies have
focused on how these treatments affect forest structure and function over the long term, or
our forests’ ability to adapt to climate change. Despite this, there is a widespread belief in
the policy arena that timber harvesting is an effective and necessary tool to address beetle
infestations. That belief has led to numerous proposals for, and enactment of, significant
changes in federal environmental laws to encourage more timber harvests for beetle
control. In this review, we use mountain pine beetle as an exemplar to critically evaluate
the state of science behind the use of timber harvest treatments for bark beetle suppression
during outbreaks. It is our hope that this review will stimulate research to fill important
gaps and to help guide the development of policy and management firmly based in science,
and thus, more likely to aid in forest conservation, reduce financial waste, and bolster
public trust in public agency decision-making and practice.

A Comment on Six et al by Christopher J. Fettig, Kenneth E. Gibson, A. Steven Munson, and Jose F. Negrón, Forests 2014, 5, 822-826.

Effectiveness of Direct and Indirect Mountain Pine Beetle Control Treatments as Implemented by the USDA Forest Service,” a White Paper in response to Six et al by 28 technical editors and contributors, all with USFS Forest Health Protection.

12 thoughts on “Six et al paper on MPB Treatments, with Responses”

  1. I wonder how the forests in Western Canada are doing? Seems like they have aggressively harvested their beetle killed pine. One of the recurring problems with our public forest management is that it is extremely difficult, complicated and expensive to do any tree harvesting, for whatever reasons. In last 20 years we spent our taxpayer dollars on forest management by just letting billions of dead trees just stand there and rot. We seem to forget, or not to care, that one of the reasons to harvest trees is to create wood products for use by our society.

  2. This report and its inconsistency with forest science validated by years of further study and operational experience has been thoroughly discussed in an early post found here.

  3. Steve

    Thank you so much for this link which clearly supports what the professional foresters in this group have been saying all along:
    – “Authors of these studies conclude thinning benefits are greatest when implemented as part of a comprehensive, landscape – scale management strategy
    Ponderosa Pine – “Thinning can significantly reduce MPB – caused tree mortality, and provide for other resource benefits (e.g. fuels, watershed function, etc.), in ponderosa pine forests exposed to various MPB infestation levels when appropriate residual stocking or inter-tree spacings are achieved”
    Lodgepole Pine – “Regeneration and thinning treatments that create a mosaic of ages, sizes, structures, and species compositions across a landscape can reduce the severity of future MPB infestations … all found that thinned lodge pole pine forests experienced significantly less tree mortality compared to adjacent, unthinned areas” – Seems like a pretty strong endorsement of matrix management as I’ve repeatedly advocated. And doubly so when you consider that this also is true of wildfire risk reduction.

  4. Good Lord! I’d not poked through this before, but Six says thinning a stand kills more trees than the beetles? Without conceding that the surviving stems far more often than not will survive and grow? Twisted. There’s lots more that is off the charts, but a shame it was paid for through NSF. Never mind that Six is a bug lady, not a forester.
    I’m sorry, but it’s a shame to see “science” like this in the face of reality in practice.

  5. I’ve noticed that mother nature leaves legacy trees on her version of a MPB clearcut. It’s important for perspective to acknowledge this. She doesn’t kill em all…and the isolated green is hard to pick out of the sea of red and Dead. Since it can take a period of several years for the MPB to “work it’s way through” and kill off a particular stand, there does seem to be a “self thinning” mechanism to a MPB outbreak…that may explain the residual survival….or just write it down to natures way of assuring a continuous regeneration of a tree species.

    But to say that “thinning a stand kills more trees than the beetle”…doesn’t hold water in the Black Hills. A stand mechanically thinned to prevent MPB mortality has a residual basal area of 60BA…about 75- 13″DBH TPA. Stands that have gone through a “MPB thinning” have a basal of about 10BA…maybe 20. I have never seen a “MPB thinned” stand leave that much BA. I would characterize the “MPB thinning” as a “shelterwood seed cut, seedtree harvest, modified clearcut with reserves or a pretty darn heavy thinning “from above.” A shelterwood or Seed tree implies that there are “mature” trees in the overstory…and the MPB abhors old growth and mature. Where I have seen “mature green survivors”…I’m thinking maybe 5 TPA…10 if lucky…more seed tree the SHW. The MPB impacted stands where I have seen the most Green survivors is in dense stands of small sized sawtimber where the survivors are less than 6” DBH…hence the “heavy thinning from above.” We all know the MPB doesn’t like small diameter trees. Unlike mechanically thinning…it’s not the largest trees that survive…but the smallest. 100 years ago an early forester classified almost half the Black Hills as “scattered timber.” After seeing this epidemic…I’m starting to think the MPB had a bigger role in shaping that scenario than wildfire.

    As far as the “efficacy” of logging in managing MPB outbreaks…you have to look no further than the BH’s to see that success. And I’m sure Ms. Six is aware of it. Consider that the MPB epidemic started at the same time in the BH’s as it did in Colorado…about 2006. By 2012, some 90% of Colorado Lodgepole was dead(look for the small green spruce in the understory) while the BH’s is still green. The MPB has killed trees on an average of 20-30,000 acres/year…while the USFS has been thinning and sanitizing 25,000 acres/year…almost all of it in the MPB hit areas. 30% of the boards coming out of the BH’s sawmills are price discounted because they have “blue stain” on them. Now…unlike Lodgepole that has a long “shelf life”…ponderosa rots fast…and they don’t salvage ANY infested tree where the bugs have already flown. So….that tells us that about 30% of the timber harvested…are “infested trees.” And what’s the old “extrapolation adage”….1 tree infested this year = 5-10 trees infested the next. That acre they “sanitized” in 2008…would have been 100 acres infested today if left untreated.

    The infestation has been declining…and since there hasn’t been any “30 below for one week”…I sense that the recent wet years are having an effect. If MPB epidemics “always” start in a drought…why shouldn’t they piddle out with wet years…does it always have to be a freeze??? I have NO doubt that without logging, the BH’s would be enjoying an endless sea of dead forest like they are enjoying in Colorado. I don’t think logging is responsible for stopping the epidemic…nature will get around to that herself….but it is responsible for buying a lot of time for the cycle to run it’s course…and since the cycle has begun…we have 200,000 acres that have 75 trees/acre instead of 10….and it’s very likely that logging has “deferred death” on the rest. It would be a good study…for some bright grad student…to count the residual Basal area after MPB gets done with it.

    From an aesthetic point of view…at least in Colorado they have “alpine” vista’s to recreate in…and 30% of the forest is still green in Aspen…and just having a “species mix” helps soften the blow. We visited Grand Lake Colorado a few years ago…now it had all been salvage clearcut…and I was expecting devastation of the kind I love. When we got there they had logged of all the dead mature…but there was enough suppressed aspen and spruce in the understory…that the town just looked like a new subdivision where a landscaper had planted 10′ tall trees everywhere-LOL. In the BH’s 95% of the forest is ponderosa…and there is no understory of spruce.

    Ahh…of course…we all know the Black Hills is “sterile” because of the logging. “Because in death there’s life”…and love is hate, war is peace, blah blah blah. Ahh…10 years ago the species flavor of the month was old growth dependent…but now that beetles have killed off all that habitat in the west…and we’re terrified that all this beetle kill will lead moderate enviros to embrace logging…the new species of the month is dependent on a dead forest. After all….pine beetles have rights too!

  6. Could it be, perhaps, that the responses miss much of the point of the Dr. Six paper? Also, could it be, perhaps, that Dr. Six got quite a lot of positive responses to the paper from scientists and Forest Service folks in both the U.S. and Canada, and therefore many of the responses from other scientists aren’t actually as one-sided as it may first appear in this blog post? Perhaps it could be, or even is.

    • Matt, I’m in agreement. I guess some folks wonder what exactly the “point” was of the Dr. Six’s paper and why it was co-authored by two lawyers. Some of the responses seem like a natural reaction to what appears to be a contradiction of “science”, however her paper was obviously pointed towards the ever elusive intersection of science/policy.

      From Six, et al.: “It is our hope that this review will stimulate research to fill important gaps and to help guide the development of policy and management firmly based in science, and thus, more likely to aid in forest conservation, reduce financial waste, and bolster public trust in public agency decision-making and practice.”

      All of the papers seem to make good points, from my perspective. I don’t see where she or others. went too far astray.

      The conspiracy theories abounding suggest that the Six paper will be used in an attempt to further derail Agency planning efforts, much like the Hanson paper:
      and the science suggested by Baker:

      I’m guessing that’s the reason for the response to Six, et al. Something for the project file…………Ain’t it a fun game!?!?

  7. Matthew and JZ

    Matthew, I am amazed that you don’t understand what all of the fuss is about. Apparently you didn’t bother to read your opening paragraph in and the responses to your Feb. 4 2014 post or you would have known what all of the fuss was about. It is also interesting that, in your Feb. 4 2014 post, you quoted the Bozeman Chronicle’s statement as to “whether forest manipulation is effective at preventing pine-beetle outbreaks” when no forester has made such a claim here on this blog. As you read on, please focus on “risk reduction” and “landscape level”.

    I think that the main problem here is that Six denies the preponderance of evidence in favor of “indirect control” by using thinning for risk reduction of future outbreaks and limiting the size of outbreaks when used at the landscape level. Read the two links at the bottom of Steve’s opening post (especially the second) and you will see what Six has missed or dismissed in her search of the literature. – The last link in Steve’s opening post includes photos –

    To conclude:

    I and the other links do agree with Six on the questionable value of direct control after an outbreak has occurred.

    The major issue at hand is the value of indirect control by thinning for risk reduction in the future at the landscape level rather than on a single thinned stand or a few isolated thinned stands buried in the midst of an un-thinned forest where excessive density and the resultant low vigor is like a dinner bell to a farm hand whose been out working in the sun all day.

    The minor issue here is whether direct control is effective on small hot spots caught early in order to keep them from escalating into an outbreak. There is absolutely no question that it is effective on the Southern Pine Beetle which is a member of the same Bark Beetle genus (Dendroctonus) and therefore a relative of the Mountain Pine Beetle although the SPB is more evolutionarily advanced.

    Please note my earlier comment in this same thread which you either missed or dismissed.

    • We can all watch this process unfold, in the aftermath of the Rim Fire. Yes, it has already started, with perfect conditions for a major outbreak, here in the Sierra Nevada. We’ve already seen trees turning brown during the winter, and it has continued as temperatures are warming up. There hasn’t been much cold this winter, either. We’re in a severe drought, as well. When bark beetle populations get so large, even healthy trees cannot survive the “shotgun effect” of too many holes to “pitch out”. We’ve seen this process before, after the 1987 Complex fires burned 175,000 acres on the same Ranger District as the Rim Fire. That bloom traveled northward, reaching the Plumas National Forest, 200 miles away. It wasn’t just in the pines, too. There was severe mortality in the higher elevation true fir belt, too. Lake Tahoe’s forests were decimated.


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