Climate Change and Wildfire Risk: Will Future Forests Be Treeless?

Candice Gaukel Andrews January 7, 2014 28
Grand Canyon firefighter

A firefighter puts out a blaze on the North Rim of the Grand Canyon. ©Candice Gaukel Andrews

Last fall, in the midst of burned and charred trees left in the wake of Yosemite National Park’s Rim Fire, I participated in, of all things, a wedding.

It was the most beautiful wedding I have ever attended. The contrast of the light colors of the bride’s dress and our group’s heady happiness set against the backdrop of black trunks and gray ash brought an intensity of meaning to the affair; new lives beginning while somewhat older lives were washed clean to sprout and start again. After all, fires have always been essential to the health and ecology of western forests.

However, recent blazes — sprawling, raging infernos such as last year’s Rim Fire in California — may be a lot different from those of the past. And so, biologists fear, will be the ecosystems that grow in their wakes. 

A Different Kind of Fire

Yosemite’s recent Rim Fire left little in the way of seeds, nutrients, shade, or moisture. ©John T. Andrews

Historically in the Sierra Nevada, low-intensity, natural fires would burn intermittently through the understory, allowing the mature trees to survive and leaving behind only scattered patches of severely burned forest — usually between a quarter acre and a half acre. Rarely did such parcels exceed ten acres.

The giant Rim Fire of 2013 — the biggest wildfire on record in the Sierra Nevada — however, had a high-severity burn area of more than sixty-three thousand acres, where trees were left blackened and dead. Such extreme fires can vaporize foliage and leave little in the way of seeds, nutrients, shade, or moisture to enable a forest to rebuild itself. If a place experiences such a fire, you may not see trees growing in it for a long time.

What’s causing this metamorphosis of fire behavior that’s turning our Western forests into “bombs” that go off every summer? While most agree that there’s no single factor that’s responsible — theories from historical fire patterns to the effects of bark beetles on fuel loads have been postulated — there are two factors where broad consensus exists: Smokey Bear and climate change.

Blaming the Bear

From 1911 through the early 1970s, Smokey Bear’s message made it clear that the goal of state and federal land management was to extinguish, as quickly as possible, all fire from the woods. The result: a timbered landscape that tends to be both mat-dense and homogeneous, with surface fuels piling up in some forests for a century or more. In once open forests, such as the central and southern Rockies’ stands of ponderosa pine, this abundance of fuel is highly combustible, feeding white-hot crown fires in ecosystems better adapted to low-intensity ground blazes. While ponderosas in open forests can withstand the latter, high-intensity events can reduce groves of even robust pines to patches of bare dirt. Because of Smokey’s fire suppression message, forests from Alaska to Arizona grew dense with fuel, leaving them prone to burning at high intensities.

Rim Fire 2013

Results of the 2013 Rim Fire. ©John T. Andrews

Denser forests are also less resilient to disease, drought, and warmer temperatures, all hallmarks of the West’s changing climate.

A Changing Climate as the Cause

Scientists have long predicted that climate change would lead to more extreme wildfires. The combination of higher temperatures and lower moisture tends to produce larger and more frequent fires. Even a small temperature increase can have an outsize impact on water evaporation. (Average summer temperatures in the U.S. have risen from 70.5 degrees from 1901 to 1910, to 71.7 degrees from 1981 to 1990, and to 73.7 degrees in 2012.) In fact, according to the United States Environmental Protection Agency, with even a one- or two-degree increase of global average temperatures, it’s predicted that there will be a 200 percent to 400 percent increase in the area burned by wildfire in parts of the western United States. In addition, earlier snowmelt extends the fire season, which in parts of the West is already ten weeks longer than it was fifteen years ago.

Burned trees, Yosemite National Park

I think the charred forest was beautiful. ©John T. Andrews

In the West, the annual burn area is already more than six times larger than it was thirty to forty years ago. Today’s blazes, instead of being healthy, rejuvenating parts of a natural cycle, cause forests to go through a process known as “type conversion.” Areas severely burned by the Rim Fire, for example, may see only grasses, shrubs, and a few shade-tolerant but fire-sensitive trees like white fir and incense cedar where once ponderosa pines and sequoias grew. Rather than the exception, fires such as the Rim Fire are probably going to become the norm. That could mean a very different future for the grand forests of the West.

I often go to the same places I’ve visited before, to see how they’ve changed through the seasons, time, and temperatures and to discover how we both have grown. When I revisited the Yosemite area last fall, I did find the charred forest beautiful. Perhaps that was because I assumed new life would spring from the ashes.

I may have been wrong.

Do you think the forests we know today are an endangered landscape? Will the “forests” of the future be treeless?

Here’s to finding your true places and natural habitats,

Candy

28 Comments »

  1. Jim O'Donnell January 8, 2014 at 10:00 am - Reply

    In some places forests will turn to scrub. In others, once treeless places will become forests. We wont have forests without trees however. What we will see is a massive shift in the species makeup of the forests with all kinds of fallout that we can’t know. Interesting times ahead.

  2. Kumar Kakumanu January 8, 2014 at 10:13 am - Reply

    I wouldn’t say tree less, but less diverse (species variety, that is) certainly, and probably even have good number of planted monoculture (e.g. trees for pulp timber etc.). It doesn’t bode well, in the tropics and emerging countries where things are worse, because fires are not due to accidents or natural related causes, but deliberately ignited by humans in most cases. Particularly, I have seen forest fires burning in India for weeks on end towards the end of the summer months; forest firefighting is the last thing in the government’s and people’s mind in most of the emerging countries. A worrisome reality indeed.

  3. Antonio Rico January 8, 2014 at 10:14 am - Reply

    In my case I am part of one of the poorest countries, we are working hard and around the clock. I am president of the Honduran Network of Private Nature Reserves (REHNAP) and we’re struggling right now, so the conservation of our renewable natural resources (which represents 49% of our territory) passes regarded as an axis of capital accumulation, thus sustainable development will have a better chance to prepare better leadership and update our courses of action. The private sector needs strong entering this dynamic.

  4. Anek Sankhyan January 8, 2014 at 10:20 am - Reply

    Kumar, you are right in pointing out frequent fires in our forests during summers. However, if our summer become hotter than at present, the incidences of wild fire would increase definitely. And, wild fire destroys many small creatures- micro-fauna and flora in particular, though mega fauna do escape out but ill fated do get burnt. it is another thing that soon during the monsoon seasons the new life springs up again as usual.

    But, such normality may not return if there is continuous temperature and summer season gets prolonged. This we can imagine at the culmination of global warming- we will not be able to live see that, future generations would bear the brunt.

  5. Alyssa Burgin January 8, 2014 at 7:24 pm - Reply

    Excellent article, thank you very much. It’s difficult to get across to people what the risk of wildfire in urban areas, in particular, will be in a world with climate chaos. A recent article by David Sirota talked about “ending the fire zone subsidy” and re-thinking sprawl into the wildland-urban-interface. We have to begin that conversation.

  6. Todd McCollom January 8, 2014 at 7:26 pm - Reply

    If we cannot get the MPB under control it will be somewhat “treeless” or rather, just less of some and more of others; after the coming fire anyway. The “fires creating a new ecosystem” is not new, exactly. It is only because of past fire retardation and other questionable forestry practices that some consider what’s happening to the forests “new.”

    Forest fires have been diminished and now the forests are in an unhealthy state, hence, hotter fires. Not a good thing as it kills the seed bed of future tree growth, not to mention what the hot fires do to the soil.

    In some areas we have too many trees, also not a good thing. Saplings cannot get the sunlight and nutrients needed to grow straight. Instead, they grow small and bent because of overcrowding.

    Certain groups will not allow logging to occur, even after a fire. Then the trees are hit by the MPB (and other bugs) because of the trees weakened state. Then you have a forest full of “red tops aka dead trees” (not a pleasant sight for those who like to take drives through the hills).

  7. Joseph Mwanza January 8, 2014 at 7:28 pm - Reply

    Wildfire is threat to biodiversty, because it destroys most of Fauna & Flora in the ecosystems. Let’s act now to prevent wildfires!!

  8. Dr.S.M.Jalil January 9, 2014 at 2:02 am - Reply

    It depends how we are aware of tree silviculture and tree management under climate change risk. Forest land conversion for agriculture, urbanization, industrialization may be other risk factors .

  9. Allen Pearson January 9, 2014 at 9:48 am - Reply

    Thanks for sharing the insight.

  10. Nareshwar Iyer January 9, 2014 at 9:49 am - Reply

    I agree to the fact, that in future there maybe more of monoculture forest with less biodiversity. We are working on climate change mitigation/adaptation. This is to do with CDM approaches. Here lies the biggest danger from carbon sequestration activities. Which means that one will have to opt for reforestation / afforestation. Herein lies the stumbling block!!! While initiating such CDM based projects we are forced to opt for pre-selected plant species such as fruiting trees or trees which grow fast and can be commercially harvested. When one is looking at social forestry on common lands and independently owned land there is not much choice but to go in for activities which will enhance local livelihood.

    Naresh
    Director
    http://www.suvidha-india.org

  11. MI Zuberi January 9, 2014 at 9:51 am - Reply

    Thanks Candice for this post…yes, we have to rethink and revise our ways of seeing events like theYosemite’s Rim Fire…the background and consequences are changed so much….and cahnged so radically in the recent years, a change of our attitude is required. There are big changes in natural and social spheres, thus these events should be viewed with more long trem and wide angles.

  12. Lawan Bukar Marguba January 9, 2014 at 9:52 am - Reply

    Both the global changing climate and forest (bush fires) fires have degraded forest ecosystems to mere bush and grasslands in much of the forested world. This phenomenon has been there for centuries and the risk from these forces would continue to diminish high forests to other less treed ecosystems.

    Tropical rain forest ecosystems in particular are fast disappearing, giving way to savanna not only due to over logging but particularly due to repeated events of forest fires and the impact of Climate Change. The only way to lessen the risks from these forces would be to cushion forests is to find some measures that will ameliorate Climate Change and incessant incidents of forest fires, otherwise the forests as we know them will eventually vanish.

  13. Jane Oteki January 9, 2014 at 9:54 am - Reply

    The current trend of forest degradation by human activities may render the forests treeless and thus a new landscape but I am optimistic that with the level of awareness creation we are headed for a better future with dense forests.

  14. Winnie Musonda January 9, 2014 at 9:54 am - Reply

    Controlled fires is a tool for forest management. Some forest ecosystems like the miombo forests of Southern Africa have, natural regeneration have depended on the controlled burning of the forests. Wild and uncontrolled fires have the potential to deplete the forests, carbon stocks and slow change the ecosystem.

  15. Joris Christiaan Wiersinga January 9, 2014 at 9:56 am - Reply

    Not wanting to sound “smart”, but here in The Netherlands the forest ecosystem is considered to be the climax stadium of natural areas, so is it not impossible to have as you state a treeless forest? I do understand that it will take hundreds of years to fully restore to its “original state” but the area eventually will turn into forest again, won’t it?

  16. Anek Sankhyan January 9, 2014 at 9:57 am - Reply

    Naresh- you are right. The social forestry or monoculture forests would create more environmental imbalance. A natural forest has numerous diversity of flora and that ultimately also become the abode of faunal diversity. This maintain natural balance. Artificial plantation is OK but it is no substitute for the natural forests. It is just like cloned hybrid vegetables and fruits which have short life and not good for health.But we are rapidly advancing towards Green houses to grow vegetables, mushrooms, flowers, etc. Are we in a right direction?

  17. Todd Masse January 9, 2014 at 9:57 am - Reply

    We tend to forget that nature has an interesting way of rejuvenating itself, and fire is one of its mechanisms. From changing old growth forests to new growth with its new ecological habitats, this is a perpetual change and development in the natural world. Anyone who disagrees with this, is more likely to view earth from a mars-like landscape.

  18. Bintoora Adonia January 10, 2014 at 7:27 am - Reply

    Indeed the forests are endagered. Climate change and variability have accentuated the negative effects of wildfires on forests. In developing countries where poor farmers depend on rain water for food production, variabilty in rainfall has led to the conversion of natural forest into agricultural fields. Adonia K Bintoora (PhD)

  19. Todd McCollom January 10, 2014 at 7:29 am - Reply

    I was just speaking of the western states in general, not global. One cannot do just one thing to the ecosystem without affecting something else; however minute (this is globally connected). Because we are an increasing population, we try to make things easier at the cost of something else. Our genetic makeup I suppose, which is not entirely a bad thing but it does come with consequences either way.

  20. Victoria Marie Lees January 10, 2014 at 11:56 am - Reply

    Thank you, Candice, for sharing your knowledge and observations with us. As an avid tree-hugger, especially the sequoias, I hope you are wrong. I know in my family’s journeys to national parks, we find a few “control burns” by, I guess, the rangers, trying to burn away the underbrush is small fires so that there won’t be a total loss of acreage like in the Yosemite Rim Fire. I can only hope that life will rise from the ashes as it has in the past. ~Victoria Marie Lees

  21. Tristam Sculthorpe January 10, 2014 at 5:51 pm - Reply

    Then they won’t be forests Candice :)

    • Candice Gaukel Andrews January 10, 2014 at 5:55 pm - Reply

      Tristam,

      Hopefully, you noticed the parentheses around “forests”! Thanks for writing!

  22. Glynn Goulding January 10, 2014 at 5:53 pm - Reply

    I am afraid that forests of the future will be totally different than at present. There are various factors involved but in my opinion global climate change is the main contributor. I rather think that the whole make up of forests will change to less robust faster growing species. More species tolerant of dry conditions will start to colonize areas after burning. This in turn would be detrimental to existing species of flora and fauna. It would probable change the eco-system in one way or another. Can we stop this change from happening probably not as it may already be to late.

  23. Lowell Tolliver January 11, 2014 at 2:47 pm - Reply

    I absolutly agree with Todd, though its unfortunate for the animals that are caught in these fires. with all the construction going on, its pushing the wildlife along with the fires into neighboring communities, it really is still a lost. we have so many different breeds of insects as well going into extinction, that really help the environment rejuvenate.

  24. Russell Donnelly January 11, 2014 at 2:51 pm - Reply

    Hello; Drought pattern occurrence is a huge aberration in the Natural Boreal Forest Norm. Vast quantities of H2O are being retained as atmospheric vapor. This may be a valid postulate for the ever increasing frequency and radius of forest fire events. This brings home the point of how intricately related our planetary spheres function one within another in a balanced accord; and how noticeably that balance can be negatively impacted by induced global climate change. Sadly; the growing global evidence stacks up against human enterprise; and the undeniable anthropogenic effect. We; as a species are the primary drivers of this disruption across the planet throughout every system.

    If our course of behavior remains unaltered; the only place we will see a forest will be in a picture ! :)

  25. Michael Hormenu January 12, 2014 at 9:55 am - Reply

    I appreciates your views. Obviously, too much of everything is bad. More so, there is an elastic limit to everything/material. Climate change and frequent wild bush fires have the potential of rendering areas subjected to such bush fires to become treeless; possibly the world may become so but not in the near future.There is the need for positive anthropogenic interventions such as afforestation projects to be encouraged to avert the world becoming treeless. Even though nature has its way of rejuvenating the system as submitted by Todd, it is important to note that the function of any material and for that matter the earth/soil, I believe has its elastic limit to tolerate destruction. Once the soil/earth does not play its recycling roles in isolation but by the help of other things( activities of micro/macro organisms, plants, animals) under favorable conditions/factors, wild bush fires therefore affect these co-actors hence the need for concern. Lets adopt more and pay listening ears to climate change adaptation measures to protect the earth and its living contents so as to sustain/elongate its natural functioning role.

  26. Saina Jeffrey January 12, 2014 at 9:55 am - Reply

    this is a very huge threat to most natural forest aldo here in the tropics. We need to carry out more wareness to the communities to control bush fires..

  27. Elizabeth Webster January 16, 2014 at 2:24 pm - Reply

    From April through October 2012 I hiked the majority of the Pacific Crest Trail (PCT). During that hike I walked through many burn areas, and had to hitch around ongoing fires; most of them in California. I made some observations along the way, and I would like to postulate a way to decrease huge devastating wildfires. I noticed areas that had formerly been logged and a lot of slash left behind were the forest tracts that burned. If loggers cleaned up and left behind less slash, I think we would see a dramatic decline in wildfires. And it is often years after logging that the excessive slash has had time to dry out and the thick blankets of moss everywhere light up with the smallest careless campfire.
    I’m not speaking against logging as a whole, just that after they leave, they should clean up. I’ve seen plenty of “natural” forests, and the snags and nurse logs and twigs and bark and leaf litter that fall naturally are far less in quantity than what’s left behind from loggers. In a natural setting this would be very little fuel by comparison, therefore not as hot and not as tall.
    Does anyone else see this?

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