Research survey does not support logging as beetle outbreak remedy

sixOne of the nation’s leading mountain pine beetle experts is Dr. Diana Six, professor of Forest Entomology/Pathology at the University of Montana’s College of Forestry and Conservation.  As the Bozeman Chronicle reported yesterday, “On Friday, in the online journal Forests, University of Montana pine-beetle biologist Diana Six and two University of California-Berkeley policy experts published a review of the scientific evidence to date on whether forest manipulation is effective at preventing pine-beetle outbreaks. The answer is generally ‘No.’”

You can download the full PDF of the study here.  Meanwhile, the full abstract follows below:

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.

Here’s a large chunk of Laura Lundquist’s article, “Research survey does not support logging as beetle outbreak remedy” from yesterday’s Bozeman Chronicle:

Logging trees in a forest can serve certain purposes, but preventing pine-beetle damage doesn’t seem to be one of them, and policy makers should stop making such claims, according to a University of Montana researcher…..Yet politicians and agency policy makers increasingly push logging projects with the claim that they will help stop the spread of pine beetles.

During the past decade, a handful of bills were introduced each year that promise bark beetle control. That number rocketed to 13 in 2013 and included bills such as Rep. Doc Hastings’, R-Wash., Restoring Healthy Forests for Healthy Communities Act.  Meanwhile, the U.S. Forest Service has a number of projects intended to ward off beetle attacks such as one in the Bass Creek area of the Bitterroot National Forest.

“We wrote this paper because we’re seeing less of an interest for policy makers to include science in policy. We don’t really have the time to write things like this but someone has to do it,” Six said. “There’s this big push to do ‘something’ and people take for granted that there’s science behind these claims. Often there is not.”

Six poured through the scientific literature for any and all studies dealing with the control of pine beetles, from direct controls, such as traps, insecticides or wholesale salvage that gets rid of infected trees, to indirect controls, such as thinning, that seek to improve the health of remaining trees to improve their odds of holding off beetle attacks.

Six points out that the problem with both types of controls is they don’t address the underlying conditions of a beetle outbreak, which is tree stress due to drought and ultimately, climate change.

“People tend to think that it’s the forest’s fault, because the trees are too thick,” Six said. “In an outbreak situation, the trees are doing worse while the beetles are doing better because of the underlying conditions.”

Direct controls are expensive and deal only with a particular section of forest, so their effect appears to be limited.

It’s actually hard to nail down the effect of various controls, Six wrote, because there has been little monitoring of forests after controls were used, in spite of the fact that the U.S. and Canadian governments have spent millions to counter recent beetle outbreaks.

In one the few large studies conducted that compared treated areas to untreated areas in Canada, results seem to show that traps and tree removal limited infestation only when beetle populations were small.

When beetle populations increase, such as during an outbreak, no treatment made any difference.

Studies showed that direct efforts to keep beetle populations down must be extensive, long-term and work only at the beginning of infestation.

Six wrote that the mechanism of thinning is not well understood as far as how it improves tree health. Many studies that record success were done right after thinning occurred and could have more to do with changes in local climate than tree health.

Six said that thinning operations that don’t diminish beetle kills are often not reported, leaving a gap in the information that could further inform scientists.

No long-term studies have looked at the effect of thinning during outbreaks.

Six noted that researchers struggle to accurately assess beetle density, which is not surprising when dealing with a flying insect the size of a grain of rice. So often, efforts to keep beetle populations low may already be too late because the population is larger than what people assumed.

During winter cold snaps, many hope that the temperatures dip low enough to kill the beetles hunkered down under the pine bark. Scientists know that temperatures need to go below minus 30 degrees and stay that low for several days to do the trick.

Six said even extended cold is no guarantee.

“Even when there’s a cold snap, there will always be some that survive. That’s what happened in the Big Hole a few years ago. Ninety percent were killed, but now they’re back,” Six said.

The paper concludes that weakening environmental laws to combat beetle outbreaks is unjustified given the high financial cost of continual treatment, the negative impacts such treatment can have on other values of the forest, and the possibility that trying to control beetles now could hurt forests as they try to survive climate change in the future.

Democratic Sen. Jon Tester’s spokeswoman, Andrea Helling, said Tester’s Forest Jobs and Recreation Act evolved out of concern over beetle outbreaks but does not argue that the mandated logging would control beetle populations.

“That said, dead trees in the urban interface are a significant fire hazard to forested communities and harvesting some of the dead trees would reduce some of the risk,” Helling wrote in an email.

———————–

NOTE: Here’s the opening paragraph of Sen Tester’s website devoted to his mandated logging bill, the Forest Jobs and Recreation Act:

“Montana’s forest communities face a crisis. Our local sawmills are on the brink and families are out of work while our forests turn red from an unprecedented outbreak of pine beetles, waiting for the next big wildfire. It’s a crisis that demands action now.  That’s why I wrote the Forest Jobs and Recreation Act.”

It’s also worth pointing out that during the first two Senate Committee hearings on the Forest Jobs and Recreation Act, Senator Tester opened the hearing sitting right next to huge blown up pictures showing bark beetle outbreaks. But, hey, Sen Tester “does not argue that the mandated logging would control beetle populations” right?

15 Comments

  1. Sounds to me like two issues are being conflated here: “What will best control a rapidly expanding bark beetle outbreak?” (apparently just about nothing), and “What is the best way for communities to respond to the beetle-induced decimation of their local forests?” There may be very good reasons to harvest trees killed or threatened by the outbreak (e.g. salvage, reduced fire risk) other than controlling beetle populations.

    • The introductory clause of the report’s 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.” is flat out wrong.

      Foresters have never claimed that management measures, such as thinning and regeneration cuts, control beetle infestations. Foresters do claim that management measures such as thinning and regeneration cuts act to prevent or mitigate beetle attacks.

      While there may be a lack of formal assessments to report long term efficacy of treatment, there are thousands of living examples of the beneficial results of management, and millions of acres of the results of non-management throughout the west. For a sample take a look at the photos in http://www.wvmcconnell.net/?page_id=545

      • In this context “control” vs “prevent” vs “mitigate” seem like semantic differences. The report brings into question the general assertion that logging has a beneficial influence on beetle outbreaks.

        • Thank you for that, Mr. Ostrich! Once again, salvage logging is just that. A process to reduce fuels by harvesting dead and dying trees. It is projects in green stands which reduces and “mitigates” bark beetles’ “habitats”. “Semantics” are for people who don’t want ANY logging, whether it is dead trees, dying trees or in crowded forests.

        • 2nd Law

          Re: ““control” vs “prevent” vs “mitigate” seem like semantic differences”
          They are significantly different in terms of forestry:
          –> Control is an effort to stop something already underway = Firefighting
          –> Prevent is an effort to keep something from happening in the first place = not really possible in forestry in terms of beetles or fires.
          –> Mitigate is: 1) an effort to compensate for a failure or a taking by setting aside another location to replace what was lost or 2) to lesson the impact of something.
          –> The job of sound forest management is mitigation in the second sense of minimizing the probability of occurrence and the extent of an occurrence of beetle outbreaks and fires. This is done by what the report calls “direct efforts to keep beetle populations down must be extensive, long-term” = Ongoing Sound Forest Management in terms of maintaining stand vigor through control of stand density. She goes on to say that they “work only at the beginning of infestation” = Direct control techniques of felling hot spots as we do very successfully here in the south by as Six says: “tree removal limited infestation only when beetle populations were small”

          Re: “The report brings into question the general assertion that logging has a beneficial influence on beetle outbreaks.”
          –> So you missed two very significant sentences in the report as follows: “Studies showed that direct efforts to keep beetle populations down must be extensive, long-term and work only at the beginning of infestation” and “tree removal limited infestation only when beetle populations were small” For an elaboration on the impact of this statement see the following:
          http://forestpolicypub.com/2014/02/04/research-survey-does-not-support-logging-as-beetle-outbreak-remedy/comment-page-1/#comment-37579 where I say: “NOW WE COME TO THE HEART OF THE MATTER – YOU HAVE TO ACT WHEN BEETLE POPULATIONS ARE SMALL AND YOU HAVE TO MAINTAIN HEALTHY FORESTS”

  2. Eli has a point that two issues can get mixed up here, but the overall issue has frequently been framed by the Forest Service, congressional proponents of increased logging/thinning with reduced environmental oversight, and others, in just such a “conflated” manner:

    For example, the Hazardous Fuels Reduction Act (HFRA) states:
    “(a) FINDINGS.—Congress finds that—
    (1) high levels of tree mortality resulting from insect infestation(including the interaction between insects and diseases) may result in— (A) increased fire risk;”
    and,
    “(a) AUTHORIZED PROJECTS.—As soon as practicable after the date of enactment of this Act, the Secretary shall implement authorized hazardous fuel reduction projects, consistent with the Implementation Plan…” http://www.google.com/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=3&cad=rja&ved=0CDYQFjAC&url=http%3A%2F%2Fwww.ag.senate.gov%2Fdownload%2Fhealthy-forests-restoration-act-of-2003&ei=kRXxUoWTHYTYoATVwYDoBA&usg=AFQjCNHPcXbJM2-8oQDdzVd09dX4011gQA&bvm=bv.60444564,d.cGU

    This excerpt is from the Forest Service’s ‘The Healthy Forests Initiative and Healthy Forests Restoration Act Interim Field Guide.’: “Except for cases of wind throw, blowdown, or ice-storm damage, HFRA Section 102(a)(4) requires the existence of an epidemic on, or adjacent to, NFS or BLM land and the imminent risk that the epidemic will spread. Resource managers need to understand the potential for such insect and disease epidemics to develop and spread.”
    http://www.fs.fed.us/projects/hfi/field-guide/web/page09.php

    So, assumptions about factors influencing MPB spread, the purported link to anticipatory fuels reduction, and effects of “proactive” silvicultural treatments become very relevant.

    This is an excerpt from a paper (overall a good paper) that I found because it was cited in the Environmental Assessment for one “fuels reduction and forest health” project in Montana, as one rationale for the project: “6. Bark beetles, fires, and forest health. A common approach to managing bark beetles in general forest areas involves sanitation and salvage in which susceptible, infested
    and dead trees are removed to reduce local population levels, decrease residual stand susceptibility, and derive some economic benefit (Jenkins et al., 2008). A more proactive approach is thinning
    in advance of an outbreak to create stands of young, small diameter trees and microclimatic conditions which are less favorable for bark beetle infestation and population spread (Whitehead et al.,
    2007). http://www.fs.fed.us/wwetac/projects/PDFs/JenkinsEt_2012_FEM_BarkBeetlesFire.pdf

    And of course, in part driven by prevailing dogma about bark beetles, the HFRA motivated the Forest Service’s so-called “Fuels CE” categorical exclusion, although in Sierra Club v. Bosworth 510 F.3d 1016 (9th Cir. 2007), the court slapped down the FS for violating NEPA by promulgating a categorical exclusion for all fuel reduction projects less than 1,000 acres and all burn projects less than 4,500 acres (the “Fuels CE”), under auspices of the HFRA. http://www.elawreview.org/summaries/environmental_quality/sierra_club_v_bosworth.html

    So the issues are very much intertwined. Regardless of who’s right, I think it’s a good thing that scientists like Prof. Six and her team are actually looking at the evidence, something that is probably long overdue.

  3. There are multiple benefits to salvage logging projects but, few people are saying that salvage logging will control bark beetles. The best defense against bark beetles, in many forests, is an abundance of groundwater, which supports the trees’ natural defenses. Ironically, some people seem to prefer protections for prime bark beetle habitat.

    Now, what kinds of treatments can increase groundwater in our forests?!?

    • Maybe beetle induced mortality helps mitigate forest overstocking and thus increase the vigor in the remaining trees and possibly reduce stand-level ET and increase groundwater availability to remaining trees. In other words, beetle related mortality is part of a self-correcting mechanisms that does not require road construction, or soil damage, or snag removal, weed vectors, etc.

      • From 1988 to 1992, we salvaged 300 million board feet of salvage, on just our Ranger District. There were no permanent roads installed, very little soil damage, ample amounts of snags left for wildlife and I haven’t seen a weed problem since then. You assume WAY too much. And yes, catastrophic wildfires are also examples of “self-correcting mechanisms” that impact humans unnecessarily.

      • 2nd Law

        Re: “Maybe”
        –> Now that is real science

        Re: “Maybe beetle induced mortality helps mitigate forest overstocking and thus increase the vigor in the remaining trees and possibly reduce stand-level ET and increase groundwater availability to remaining trees”
        –> Thinning reduces competition for available groundwater and reduces evapo-transpiration thereby increasing the probability that there will be sufficient ground water availability for the remaining trees.
        –> Beetle Outbreaks do not leave remaining trees except for an occasional patch which is just as dense as before the outbreak and therefore just as starved for available groundwater.

        Stick with the law – Your suppositions about forestry only reveal your lack of knowledge.

  4. The real question is how does logging damage the pine beetle infected forest? If you log with a helicopter, and take the larger dead trees, build no new roads, exactly what is the damage? And how does the logging impact global temperature regimes? I can visualize how fewer limbs, fewer needles dead or alive, will reduce sublimation be having more snow on the ground, not suspended in air, which could change retained snow amounts and spring runoff timing to later into the ever longer days of spring to summer.

    The research, or lack thereof, states that the beetles will kill trees no matter what you do or don’t do. So the question becomes one of which use of the dead material is best for the community of man. It is our decision, after all. Which berries do we pick, what nuts do we pick up, when is it best to take a deer, what trees might we take and when, all are part of the human condition. You can doubt it all, but by doubting you do claim dominion. Now the issue is who makes the rules of dominion.

    • You had me at “take the larger dead trees” and asked how this would damage the forest. The answer: Removing large dead trees will typically harm the forest quite a lot. This is because large trees are rare; they take a long time to grow and a long time to replace. They provide valuable habitat not just when they are alive but also when they are dead. Think of trees having two lives – one alive and one dead. The abundance of snags that is apparent during mortality events like beetle outbreaks is misleading because it hides a future shortage of snags. This is because the mortality event reduces the population of green trees that are necessary for long-term recruitment of snags over time. Salvage logging reduces a rare and valuable resource and makes the future shortage of snag habitat even worse. Read this: Rose, C.L., Marcot, B.G., Mellen, T.K., Ohmann, J.L., Waddell, K.L., Lindely, D.L., and B. Schrieber. 2001. Decaying Wood in Pacific Northwest Forests: Concepts and Tools for Habitat Management, Chapter 24 in Wildlife-Habitat Relationships in Oregon and Washington (Johnson, D. H. and T. A. O’Neil. OSU Press. 2001) http://web.archive.org/web/20060708035905/http://www.nwhi.org/inc/data/GISdata/docs/chapter24.pdf

  5. Here is what is wrong with the whole report

    “Six points out that the problem with both types of controls is they don’t address the underlying conditions of a beetle outbreak, which is tree stress due to drought and ultimately, climate change.”
    –> Tree stress is compounded, no matter the conditions, by stand densities beyond the point where stand health/vigor deteriorates due to excessive competition for limited resources.

    ““People tend to think that it’s the forest’s fault, because the trees are too thick,” Six said. “In an outbreak situation, the trees are doing worse while the beetles are doing better because of the underlying conditions.””
    –> The trees are too thick because of the lack of management. She is correct in her statement that once you have an outbreak it is pretty much unstoppable – But what happens before that matters greatly as will be discussed later in this comment.

    “Direct controls are expensive and deal only with a particular section of forest, so their effect appears to be limited.”
    –> Each situation is different but generally, if you wait too long to take action, direct controls are ineffective no matter how expensive they are.

    “In one the few large studies conducted that compared treated areas to untreated areas in Canada, results seem to show that traps and tree removal limited infestation only when beetle populations were small.”
    –> NOW WE COME TO THE HEART OF THE MATTER – YOU HAVE TO ACT WHEN BEETLE POPULATIONS ARE SMALL AND YOU HAVE TO MAINTAIN HEALTHY FORESTS. in the South, we learned back in the 70’s to lay the trees on the ground as soon as any hot spots were spotted by regular aerial surveys. It is a proven effective control mechanism, unfortunately, the MPB isn’t dealt with as easily. As we have learned in the south, there are certain densities (120ba for Loblolly pines) above which you had better not go unless you want a pine beetle outbreak. The link below indicates a similar density relationship to MPB incidence. As discussed elsewhere on this blog (before it was moved), even the head USFS entomologist for the Colorado Spruce Pine Beetle said ‘the anticipated loss of 90% of the spruce in Colorado could have been greatly reduced if the USFS had taken action to address the initial spots that occurred in a wilderness area’.

    Try this link on for a more balanced view http://www.ext.colostate.edu/pubs/insect/05528.html

  6. Gee, another scientists say paper —
    Logging alone won’t moderate a beetle outbreak unless it’s enough logging to allow the remaining trees to take up water and drown beetles. On the other hand, too much wood and too little water brings us wonderful things like the mortality on Flesher Pass. The trees all fought themselves for water and when the drought stayed around, there was no way. In two years, everything was red and dead.

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