New Report: Climate Change Could Cripple Southwestern Forests

From the University of Arizona:

Combine the tree-ring growth record with historical information, climate records and computer-model projections of future climate trends, and you get a grim picture for the future of trees in the southwestern United States.

That’s the word from a team of scientists from Los Alamos National Laboratory, the U.S. Geological Survey, the University of Arizona and other partner organizations.

If the Southwest is warmer and drier in the near future, widespread tree death is likely and would cause substantial changes in the distribution of forests and of species, the researchers report this week in the journal Nature Climate Change.

Read the entire article here.

Also, I’ll paste the Abstract of the study below, but the entire study may be view here.


As the climate changes, drought may reduce tree productivity and survival across many forest ecosystems; however, the relative influence of specific climate parameters on forest decline is poorly understood. We derive a forest drought-stress index (FDSI) for the southwestern United States using a comprehensive tree-ring data set representing AD 1000–2007. The FDSI is approximately equally influenced by the warm-season vapour-pressure deficit (largely controlled by temperature) and cold-season precipitation, together explaining 82% of the FDSI variability. Correspondence between the FDSI and measures of forest productivity, mortality, bark-beetle outbreak and wildfire validate the FDSI as a holistic forest-vigour indicator. If the vapour-pressure deficit continues increasing as projected by climate models, the mean forest drought-stress by the 2050s will exceed that of the most severe droughts in the past 1,000 years. Collectively, the results foreshadow twenty-first-century changes in forest structures and compositions, with transition of forests in the southwestern United States, and perhaps water-limited forests globally, towards distributions unfamiliar to modern civilization.

7 thoughts on “New Report: Climate Change Could Cripple Southwestern Forests”

  1. (from the article)
    “Consistent with many other recent studies, these findings provide compelling additional evidence of emerging global risks of amplified drought-induced tree mortality and extensive forest die-off as the planet warms.”

    Consistent with predictions issued decades ago, we are not short on evidence of present and impending catastrophic effects of climate change and what drives it — yet very little efficacious policy is actually being applied to the problem. (Notice how this impending catastrophe has been almost entirely disappeared by the media coverage even at the height of presidential campaign season.)

    Nor are we short on market based solutions (sic) claiming to advance conservation strategies for handsome profit taking off these unfolding catastrophes.

    We are definitely short on the will (and applied scientific research) to call into question those powerful (“nonprofit” !) philanthropic foundations heavily invested in planet-killing multi-national corporations which then — in the name of charity — use the proceeds of their investments to fund national environmental orgs to maintain business as usual or advance false solutions to our climate catastrophe using the tools of “free market environmentalism”.

    While, “The master’s tools will never dismantle the master’s house.” (Audre Lorde), those tools are certainly dismantling and transforming our planetary paradise into a holy hell with the sociopathic motive of fantastic personal profit taking at ALL costs.

    It doesn’t have to be, nor end, this way. We need more will though, and a clear distinction between what passes for charity and the urgently necessary application of justice.

  2. As I’ve said before, given what we don’t know about plant adaptations.. it’s all quantified assumptions.

    It’s worth thinking about though- if that scenario does occur, the idea that if we stop doing anything species will be fine won’t work, and all these efforts, lawsuits, etc. will be for naught.

    Thinking more broadly, is there a better way?

  3. Sharon, I don’t know of many people or organizations advocating that we “stop doing anything,” so why do you portray it like that?

    Also, I could re-arrange your comment to say, it’s worth thinking about though- if that scenario does occur, the idea that if logging and thin the forest the trees and the species will be fine won’t work, and all this logging, taxpayer expenses, etc will be for naught.

    Wouldn’t that be equally as valid an argument in favor of not following, for example, the “pre-settlement’ model in the southwest favored by Covington?

    • Matthew, thank you for those great comments. You make me think…

      First of all, the “stop doing anything” I had recently read this. on the Breckinridge Peak 6 appeal.

      Though deciding official Fitzwilliams said the region around Peak 6 is already unable to meet federal standards for lynx habitat, opponents of the expansion say impacts are not weighed by the need to ease crowding.

      “Lynx habitat is going to be hurt by fragmenting the area they travel,” Smith said. “The Forest Service seems to think that since the habitat is already so bad it’s okay to make it worse. It has been affected, no question, by the existing ski area. Right now it is impaired somewhat, but it’s not severed. This expansion might sever it.”

      Fitzwilliams and researchers for the Forest Service looked at conservation efforts in the project area, but said they “found very few if any that would help lynx at all.”

      “There is no question that there are impacts,” Fitzwilliams said. “The region surrounding Peak 6 does not meet federal standards for lynx habitat, regardless of the expansion we really couldn’t meet that standard.”

      The resident population of lynx in Summit County, who are known to use Copper Mountain, Vail Pass and the area near Climax Mine, is estimated to be approximately six animals, according to Jake Ivan, a wildlife researcher with Colorado Parks and Wildlife.

      Now a piece of information that seems relevant is that lynx was reintroduced to Colorado to the south of most current lynx populations.

      Here’s another piece that talks about current recreation being “curtailed” to help protect this reintroduced species.

      It seems like there is an overall idea that we should “stop doing things that impact lynx”.. but what if we stopped all those things and the lynx still couldn’t make it due to climate change?

      Another thought is “isn’t it rational to not want reintroductions of endangered species if it means that people can now legally stop you from your current uses on the forest if it is shown to have an impact on the newly reintroduced species.”?

      Second, fuel treatment has a relatively short-term benefit… to change fire behavior around homes and communities so that firefighters can more safely protect that infrastructure.

      It seems to me more likely that we will continue to have fires near communities in the Intermountain west in the next 30 years, than habitat for lynx will continue to occur in Colorado for the next 200.

      Anyway, that’s how I got to the thought about “stop doing anything”. I probably should have posted on the lynx separately.

      Finally, I am not a fan of trying to manage to “presettlement” for a variety of reasons, generally it obfuscates the fact that it is impossible to do it and we are making social choices about which things to return to, and which things not to, under the guise of “science”. I think you and I agree about this, but perhaps for different reasons.

  4. I read someplace else that in the face of climate change, ponderosa pine is one of the species best adapted to drying weather. From what Colin has said on the HCN site about his observations of the sharp decline in the historic extent of PP in NM in drier lower elevation sires, this hopeful view does not seem to be the case.

  5. Greg, ponderosa pine is more adapter to dry than other species that it is sometimes mixed with, say true firs, Douglas-fir. However when it gets to real dry, in the southwest, it goes to pinyon or juniper. So it really depends on where you want it to stay or move to.

    Also, it’s hard for tree species to get started sometimes but they could do OK if they had help (say, planting) getting started.

  6. This is a really interesting conversation. Thanks to Mathew for the posting. I particularly liked the exchange between Sharon and Mathew in which each, in the face of uncertainty, is expressing their bias. In fact, the entire debate over forest management in the face of climate change could be wonderfully summarized by their short little exchange. Mathew makes and excellent point in turning Sharon’s question back onto itself to point out that going along with the prevailing assumptions on the subject (i.e. large-scale forest thinning is a good thing in SW forests) could be just as harmful (if not more) than taking a different approach. Although Mathew didn’t elaborate here, my sense is that he is leaning toward a much more cautious/conservative approach. Given the scientific reports that Mathew often posts here, my sense is that he is not nearly as “sold” on the “forest thinning as solution” model as others are.

    But the real interesting point for me is the question of how we respond (live with) to uncertainty. Science has always left a certain degree of uncertainty, but in the case of NF management, most of this uncertainty has been confined to a particular drainage or region and has been centered around the cumulative effects of activities. Today, however, what we are really grappling with are the cumulative effects of fossil fuel based industrial activities and technologies on a global scale. This is an unprecedented degree of uncertainty and I believe it is more important than ever to maintain our humility in the recognition that none of us has the “right” answer, and yet, we have to make decisions and move forward. In the words of Benjamin Franklin, “now we must all hang together, or we will most certainly hang separately”.


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