Extreme wildfires are changing Western forests

Extreme wildfires are changing Western forests

Here are three recent studies that examine the ways in which the connections within ecosystems are altered by more powerful wildfires – The titles pretty much tell it all:

1) “High-severity wildfire limits available floral pollen quality and bumble bee nutrition compared to mixed-severity burns,” Oecologia, December 2019
“In areas with more severe burns, pollen had almost 28% less nitrogen than in areas with mixed-severity burns. That pattern was mirrored in the bumblebees themselves: Those from more severely burned areas had less nitrogen in their system. Nitrogen is an indicator of the amount of protein in pollen — a crucial piece of the insects’ nutrition — and bees that consume more protein are larger and more resistant to parasites and disease.”

2) “High-severity wildfire leads to multi-decadal impacts on soil biogeochemistry in mixed-conifer forests,” Ecological Applications, January 2020
“They found that, even four decades after the blaze, the amount of organic carbon was lower in soils affected by wildfire. Organic carbon promotes plant growth and is critical for soil health: It allows the soil to act like a sponge and hold more water and nutrients, and it binds fragments of the soil together, thereby reducing erosion.”

3) “Fuel treatment effectiveness in the context of landform, vegetation, and large, wind-driving wildfires,” Ecological Applications, February 2020
“In areas that received treatment, more mature ponderosa pines survived the fire. That may not seem surprising, but the researchers hadn’t expected the strategy to be so effective during such an extreme and long-lasting fire, said Susan Prichard, a fire ecologist at the University of Washington and lead author on the study.
As huge wildfires like the Carlton Complex become more common, preparatory land management will be even more crucial. Actions like tree thinning and prescribed burns help preserve fire-resistant trees that can spread seeds for future vegetation growth after a blaze. “I really hope that our study comes off as an optimistic view of what we can expect in the future if we are proactive,” Prichard said. “

17 thoughts on “Extreme wildfires are changing Western forests”

  1. It’s interesting how some scientists seemed to think that if high-severity wildfires had happened within NRV then they must be “good”, even if those fires caused soils, watershed, fish and animals to have a tough time. People who study soils and bumblebees find that it’s not good for them (the soil part I think we knew, at least in some areas, by watching them wash away).

    “Science” tells us…

    • Yes, the soils part is long established science as is forest management for minimizing fire risk. Too bad people disdain established science when it doesn’t agree with their opinion.

  2. It’s also interesting how some think that soils, watershed, fish and animals having a “tough time” can’t be “good.” I see the Forest Service saying it all the time – short-term adverse effects are fine if there are long-term benefits.

    • Are you saying the USFS has become an eco freak or are they just gun shy of eco freaks?

      In cases two and three the negatives are both short, mid & long term. There are no benifits and they are but a few of the negatives. Case one, i have no idea where it stands in terms of duration but does it even matter considering the other two cases?

      What are some examples of “short-term adverse effects are fine if there are long-term benefits” that you have seen “all the time”?

      • I’ve been reading some forest plans, but I’m sure they say things like this in about the effects of vegetation management in most project NEPA documents. Here’s a couple of examples from draft revised plans:

        Nantahala-Pisgah WTR-G-02 … “Short-term exceedance of water quality standards (i.e., temporary period of declining water quality) due to management activity occurs only in the anticipation of long-term improvement of watershed condition and water quality.”

        Nez Perce-Clearwater FW-STD-WTR-04. … “Short-term adverse effects from project activities may occur when they support the long-term recovery of aquatic and riparian desired conditions and federally listed species.”

        My point was really the same as 2ndLaw’s – if the high-severity fire is what the ecosystem is adapted to then the bees and the soil are the trees are going to be fine.

        From the revised plan DEIS: “Floods, landslides, and debris torrents are natural events, often associated with wildfires, which are included in the disturbance regimes of many stream reaches on the Nez Perce-Clearwater. Although the short term effects may be deleterious, particularly in streams already degraded, it is believed some stream systems may be dependent on these sorts of events to sort gravels, create spawning habitat for salmonids, and recruit large amounts of woody debris in a pulse event, all of which can increase habitat complexity and productivity long-term (T. Beechie & Bolton, 1999; Reeves, Benda, Burnett, Bisson, & Sedell, 1995).”

            • I think that’s a shorthand for plant communities in which the dominant species of plants are adapted to fire. Like prairie grasses, or shrubs or forest trees. But let’s take a mountain lion in southern Cal.. it’s no more “adapted to fire” than any other mountain lion, I shouldn’t think. Let’s think about the trout.. they are not adapted to fire. Nor the viruses on the flea on the ground squirrel and so on.

              • Based on Nez Perce-Clearwater quote above, I would say that trout have/are adapted to fire that causes flooding: “some stream systems may be dependent on these sorts of events to sort gravels, create spawning habitat for salmonids, and recruit large amounts of woody debris in a pulse event, all of which can increase habitat complexity and productivity long-term. I think message in the concept of “fire-adapted” is that some ecosystems, and necessarily their components, need fire to sustain themselves, so suppressing fire is bad from the context of ecological integrity.

  3. Sometimes “having a tough time” is just what the forest needs. For instance, mistletoe persists in mixed severity fire. It does not get really pushed back until severe, stand-replacing fire occurs. Maybe true of other “pests.”

    The study of fuel reduction effectiveness in the Carleton fire is mostly just anecdotal. Do determine whether fuel reduction is “worth it” you have to look at the total impacts of fuel reduction across the landscape, including many places that are logged and NOT burned, then compare to cumulative effects of logging plus unavoidable fire, versus fire alone. Many forest values end up being degraded more by logging (plus fire), including carbon storage, and habitat for wildlife that prefer relatively dense, complex forests, e.g. goshawk, marten, pileated woodpecker, etc.

    • No. I don’t think logically that you “have to” look at “total fuel reduction across the landscape.” I think that’s a values question, of at what scale, and based on what values, does who (making the judgment) look at the success of a project or practice? Can a project be successful in reducing risk to a community without looking at a “landscape scale”?

      Basically it’s a value judgement of whether the desirable outweighs the undesirable effects.

      What you seem to be saying is that “you have to look at total impacts across the landscape” .. which is generally what folks do in their NEPA for fuels treatment. They may come to different conclusions than you do, because they are looking at specific places and situations, or make different assumptions about different things.

      Folks can place different values on “large tree survival” or “soil protection” versus other variables. But I don’t see measuring trees as “anecdotal” and generally less desirable than modeling many unknowns. Here’s what might work to bring these perspectives together, IMHO.

      Pick an area that makes some ecological sense. Generate models for impacts of fuel treatments. Get input from all related disciplines, fish, wildlife, soils, plus practitioners in those fields (in a public way), make all assumptions and data usage transparent, plus fuels and suppression specialists on the models. After five years, take all the data from fuels treatments and fires and see how well the model worked to predict impacts, involving all the disciplines and practitioners you rounded up in the first place. I think then we might know a lot more (about that area).

  4. Most any forest ecologist will tell you that the western landscape in the United States is compromised of numerous ecosystems that evolved with “extreme” wildfires. Also, much of what burns in the Western U.S. isn’t even considered a “forest.”

      • Sharon: Numerous ecosystem in the West have evolved with “extreme” wildfire.

        If you take exception to that fact, please contact the California Department of Fish and Wildlife and let them know that they are spreading false information. See: https://wildlife.ca.gov/Science-Institute/Wildfire-Impacts

        “Almost all of California’s diverse ecosystems are fire-dependent or fire-adapted. Fire-dependent ecosystems need wildfire to maintain appropriate function and health, while fire-adapted ecosystems have evolved to survive wildfire.

        P.S. Some common definitions of an Ecosystem (Jeez, can’t even believe we are having this nit-pick debate).

        A biological community of interacting organisms and their physical environment.a biological community of interacting organisms and their physical environment.

        An ecosystem is a geographic area where plants, animals, and other organisms, as well as weather and landscape, work together to form a bubble of life.

        An ecosystem consists of a community of organisms together with their physical environment.

        Ecosystem, the complex of living organisms, their physical environment, and all their interrelationships in a particular unit of space.

  5. Matthew, I’m not trying to be pedantic. I’m trying to help people understand how organisms and assemblages of organisms operate. Species adapt to their environments, including their relationship to other species. Species migrate hither and yon through time and have impacts on other organisms. The “evolved ecosystem” sounds like it’s a static thing, but it’s got a million changing and moving parts that all evolve according to different timeframes. For example, fires on a 30 year frequency, and an insect’s five month lifespan.

    And I’m not the only person who thinks this… based on the lack of a mechanism for “multiple species/taxa adaptation” From a piece by Wendy Fulks on writing about wildland fire on the Fire Adapted Communities Learning Network. https://fireadaptednetwork.org/avoid-these-pitfalls-when-writing-about-wildland-fire/

    “That ecosystem didn’t “evolve” with fire. Strictly defined, the process of evolution applies to individual species, not to ecosystems.”


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