Typical Student ESS Response to Yellowstone Fires Scenario
ESS Analysis of the Yellowstone Fires of 1988
Problem Statement:
Fires are a natural part of the Greater Yellowstone Ecosystem. That ecosystem evolved with fires and fires continue to be a tool that land managers may need to use to keep the ecosystem in balance. However, because of human incursions into the natural ecosystem, there is a limited amount of forage, space, and fresh water for the wildlife in the area. Fighting fires may be necessary to keep the ecosystem intact and functional. Our goal is to determine if there is a need to fight natural fires or if the ecosystem is best left alone (fire included).
Recommendations:
We recommend that natural fires be allowed to burn in Yellowstone National Park. This is in the best interest of the Greater Yellowstone Ecosystem and the people who enjoy the area. By allowing natural fires to burn, fuel loading will be reduced and biodiversity will be maintained.
EESS Analysis:
A>E
During the mid to late summer of 1988, Yellowstone National Park was the driest it had ever been in 116 years of recorded history. During that summer, more than a third of the Park’s area (>793,000 acres or 1240 square miles) was affected by fire. Fires that had started outside the park’s boundaries burned more than half that total acreage. Of the 51 individual fires, lightning naturally started 42 of them (lightning starts as average of 22 fires each year). Most of the 1988 fires extinguished naturally by autumn rain and snow (80% of naturally started fires go out by themselves). (http://www.us.national-parks.net/fire.htm)
According to Trenberth, et.al. (1988), the exceptionally dry conditions were the result of long-term climate conditions in the tropical Pacific Ocean in 1986-87, an “El Nino” year. Following the El Nino, the 1988 La Nina conditions (below average sea surface temperatures in the equatorial Pacific) set up causing warmer waters to be displaced away from the equator. This caused unusually warm atmospheric conditions southeast of Hawaii and low precipitation in the early months of 1988 in the western U.S.
E>A
When fire burns, the smoke and particulates fill the air creating health hazards for animals and humans. During the 1988 fires, smoke was particularly bad in the areas northeast of the park due to the dominant southeast wind direction. (Franke, 2000)
B>E
According to the National Park Service, humans started only 9 of the 51 fires. The total cost to fight all the fires was $120 million. 25,000 firefighters worked to save human life and property but had little impact of the extent of the fires.
The impacts of the mountain pine beetle were studied by Lynch et. al. (2006). They found a strong correlation between the spatial pattern of burned areas to the areas affected by a pine beetle outbreak in 1972-75 but no correlation with the outbreak of 1980-83.
E>B
Soil horizons and lake sediments in YNP indicate that the ecological system is well adapted to large fires. These records show 250-400 years cycles of large forest fires and 25-60 year cycles of grass fires in Yellowstone. (http://www.yellowstone-bearman.com/yfire.html)
In the 793,880 acres of Yellowstone National Park that burned, a forest mosaic was created, according to Knight, et.al (1989) and Franke (2000). There were three types of fires, each affecting the forest differently:
• Crown fires burn hot and fast through the canopy of the forest. During the 1988 YNP fires, these consumed 41% of the burned areas.
• Mixed fires burn both the tree canopy and/or the ground vegetation in an area.
• Ground fires burn low vegetation (grasses, forbs, and shrubs) as they move slowly across an area. This type of fire can penetrate the duff layer of the forest floor, killing the root system of a tree that did not burn.
The patchiness of the burn allowed for quick and natural recovery. Areas that were intensely burned were within 200 meters of areas less affected by the fires. The seeds of Lodgepole pine are released from the cones when the parent trees burn. Fireweed (Epilobium angustifolium) seeds blow in from surrounding areas. Within a few years, Engelmann spruce, subalpine fir, Douglas-fir, and whitebark pine have emerged. Grasses, some forbs, and aspen trees spread from their roots. The bare mineral soil left behind by the fires provided good conditions for aspen seedlings. (Knight, et.al (1989) and Franke (2000))
Of the approximately 40,000-50,000 elk that lived in YNP in 1988, 345 perished in the fires, along with 36 mule deer, 12 moose, 6 black bear, 9 bison, and one grizzly bear. For the animals that survived the fires, finding food the following winter was challenging. However, the following years, food was plentiful, easier to get to, and more nutritious.
Fire retardant dropped into two streams resulted in the deaths of approximately 100 fish. Besides that, there has been no observable impact on the native fish populations in the park. Birds that nest in tree cavities increased in population after the fires, birds who were dependent on mature forests lost habitat and their numbers declined. (http://www.us.national-parks.net/fire.htm)
Currently, the Greater Yellowstone Ecosystem is considered a relatively intact ecosystem with strong biodiversity. This region is one of the few places left in North America where the animals that roamed most of central North America can all be seen in one place. (http://www.greateryellowstone.org/ecosystem/)
G>E
Much of the park has rhyolitic soils, which do not retain water very well. When there is very little rainfall, the soils dry out very quickly causing the vegetation to dry out as well, making them more susceptible to fires (Franke, 2000). In areas where the soils are older and better developed, water holding capacity was greater and the vegetation was less likely to be burned as intensely. (http://www.us.national-parks.net/fire.htm)
Slope angle and aspect can affect the intensity of the burn. Forests tend to be more dense on north-facing slopes because they receive less direct sunlight and have a higher soil water content. These hillsides are less likely to ignite in normal conditions but burn much hotter in drought conditions due to the fuel load (Martin, 2000)
E>G
When forest fires burn, there are numerous impacts on the geological environment. According to USGS reports, the geomorphology of the western U.S. is changed most rapidly by erosion and deposition after fire events (Martin, 2000). Not only are soils enriched with nutrients previously locked up in the trees but the rocks that make the soils are broken down faster by the rapid heating and cooling, leading to exfoliation and spalling. When heated by intense fires, some of the soils become hydrophobic (water is not absorbed but runs off) causing an increase in erosive capacity of the water. The hotter the fire, the more likely this happens.
When soils and sediments are eroded off of the hillsides, they can move as hyper-concentrated flows, debris flows, and landslides into lower lying regions. In the western U.S., there are few events that lead to the massive movement of sediment like forest fires do (USGS, 1999). These events forever change landscapes that have seemed stable and unchanging: stream channels shallow or deepen, alluvial fans become active, landslides and debris flows redistribute sediment quickly and dramatically.
H>E
The winter and spring of 1987-88 was very dry. However, heavy precipitation in May and June caused a surge in the growth of grasses and forbs, increasing ground fuels. Higher humidity areas around lakes, streams, and rivers did not burn as intensely as drier areas. (Franke, 2000; http://www.us.national-parks.net/fire.htm)
E>H
There was very little direct impact on the water. The impacts were the result of the fires affects on the air and soil. See following:
E>H>G>H
As with many wildfires, land managers were very concerned with erosion after the fires of 1988. Spring runoff and summer thunderstorms can overwhelm the soils, running straight into streams, rivers, and lakes. The water carries sediment into the waterways, causing a decrease in stream depth. Sediment inflow into the Gardiner, Gibbon, and Madison rivers were notable during the spring and summer months of 1989. (Franke, 2000; http://www.us.national-parks.net/fire.htm)
E>B>H>G
In the efforts to fight the fires, millions of gallons of water were dropped on the fires or pumped to the fires. This caused a decrease in stream flow and washed soil and ash into the streams. More than a million gallons of ammonium phosphate based fire-retardant ended up polluting some streams, but this was a transient impact, having no long-term effects on water quality.[ (Franke, 2000)
E>G>B>G>H
Since the fires, vegetation growth has slowed erosion in watersheds that had erosion and mudslides after the fires, such as the Gibbon, Gardiner, and Madison Rivers (Turner, et.al, 1994).
E>B>A>B
According to Franke (2000), the Montana Department of Health and Environmental Sciences and the park recorded 19 days in Gardiner and 7 days in Mammoth where recommended allowable particulate concentrations were exceeded. On the worst days smoke could be seen for up to 60 miles away. Smoke filtered down the valleys into adjacent communities. Driving became hazardous. People were treated for smoke inhalation.
E>B>A>H
When the wild fires were burning, nitrogen, carbon, and sulfur compounds are sent into the atmosphere. When mixed with water vapor, the result is acidic precipitation (http://oceanworld.tamu.edu/resources/environment-book/acidrain.html). In the case of the Yellowstone fires, I was unable to find research verifying that acid precipitation fell in the region as a result of the fires. Given the size of the fires and the dominant wind direction, I would assume that acid precipitation probably fell to the northeast of Yellowstone National Park.
B>E>B
The fires of Yellowstone National Park in 1988 were the result of climatic conditions. However, the decisions of humans in the decades prior to that year created a situation that made the fires much more intense.
Because of the deadly fires that land managers had to deal with for more than a century prior to 1988, wildfire suppression became the normal course of action throughout our country. (http://www.boisestate.edu/history/ncasner/hy210/peshtigo.htm; http://www.wilderness.net/library/documents/IJWApr06_Aplet.pdf; http://www.nrdc.org/land/forests/pfires.asp; http://www.nifc.gov/fire_policy/docs/chp1.pdf) All fires were supposed to be suppressed within 24 hours of ignition. This protected communities and natural resources and created jobs. Smokey Bear’s motto of “only you can prevent forest fires” did a great job of misleading the American public that most fires were started by people when, in fact, most are caused by lightning.
The ecological ramifications of fire suppression were beginning to be understood better (by scientists) in the early 1900’s. This knowledge was entrenched in Native American culture. Aldo Leopold wrote about it, ecologists pondered it, and land managers considered using fire to “clean up” the forest. By the 1960’s, the scientific community was encouraging the NPS to allow natural fires to “run their course” and by 1972, the NPS was letting fires burn in Yellowstone and USFS adopted this same policy for Wilderness Areas. (http://www.wilderness.net/library/documents/IJWApr06_Aplet.pdf; http://www.nrdc.org/land/forests/pfires.asp; http://www.nifc.gov/fire_policy/docs/chp1.pdf)
Ecologically, we know that suppressing fire reduces the number and variety of plant and animal species. Disease and insect infestations are kept in check by fire. Fires help to maintain a forest ecosystem. (http://www.us.national-parks.net/fire.htm)
Works Cited
"Evolution of Federal Wildland Fire Management Policy" (pdf). Review and Update of the 1995 Federal Wildland Fire Management Policy January 2001. National Park Service, U.S. Forest Service. January 2001. http://www.nifc.gov/fire_policy/docs/chp1.pdf.
"Firestorms of 1871". Disasters. Boise State University. http://www.boisestate.edu/history/ncasner/hy210/peshtigo.htm
"Wildfires in Western Forests". Natural Resources Defense Council. May 2003. http://www.nrdc.org/land/forests/pfires.asp
"Wildland Fire in Yellowstone". Wildland Fire. National Park Service. June 11, 2007. http://www.nps.gov/yell/naturescience/wildlandfire.htm.
“The Total Yellowstone Page”. 1995-2003. http://www.us.national-parks.net/fire.htm
Aplet, Gregory H. (April 2006). "Evolution of Wilderness Fire Policy" (PDF). International Journal of Wilderness 12 (1): 9–13. http://www.wilderness.net/library/documents/IJWApr06_Aplet.pdf
Franke, Mary Ann (2000). "The Role of Fire in Yellowstone" (pdf). Yellowstone in the Afterglow. National Park Service. http://www.nps.gov/yell/planyourvisit/upload/chapter1.pdf. http://www.nps.gov/yell/planyourvisit/upload/chapter4.pdf.
Knight, Dennis H.; Linda L. Wallace (November 1989). "The Yellowstone Fires: Issues in Landscape Ecology". Bioscience 39 (10): 700–706..
Lynch, Heather; Roy A. Renkin Robert L. Crabtree and Paul R. Moorcroft (January 19, 2007). "The Influence of Previous Mountain Pine Beetle (Dendroctonus ponderosae) Activity on the 1988 Yellowstone Fires". Ecosystems 2006 (9): 1318–1327
Martin, D. (Winter 2000). Studies of Post-Fire Erosion in the Colorado Front Range Benefit the Upper South Platte Watershed Protection and Restoration Project. http://watershed.org/news/win_00/5_postfire.htm
Turner, Monica; William H Romme and Daniel B Tinker (2003). "Surprises and lessons from the 1988 Yellowstone fires" (pdf). Frontiers in Ecology and the Environment 1 (7): 351–358. http://tiee.ecoed.net/vol/v3/issues/frontier_sets/yellowstone/pdf/Frontiers%5BTurner%5D.pdf
Turner, Monica; William W. Hargrove, Robert H. Gardner, William H. Romme (November 1994). "Effects of Fire on Landscape Heterogeneity in Yellowstone National Park, Wyoming". Journal of Vegetation Science 5 (5): 731–742.
Turner, Monica; William H Romme and Daniel B Tinker (2003). "Surprises and lessons from the 1988 Yellowstone fires" (pdf). Frontiers in Ecology and the Environment 1 (7): 351–358. http://tiee.ecoed.net/vol/v3/issues/frontier_sets/yellowstone/pdf/Frontiers%5BTurner%5D.pdf
United States Geological Survey (1999, September 22). USGS Studies Wildfire Ecology In The Western United States. ScienceDaily.
To see how students arrived at this response, see their problem-based learning responses for Week A Individual and Team below.
Cycle A – Individual
Identifying Prior Knowledge
Situation (from http://www.cotf.edu/ete/modules/yellowstone/YFmain.html):
The fires of 1988 in Yellowstone national Park destroyed millions of trees and blackened hundreds of thousands of acres. These fires were both natural and human-caused. Given the destructive nature of theses fires, should naturally-caused fires in national parks be allowed to burn to their natural conclusion. The government agencies are particularly interested in your recommendations based on your Earth System Science (ESS) analysis of a fire's impact on the air, land, water, and living things.
The next time there's a natural fire in Yellowstone National Park, should government agencies try to put it out or let it burn?
What do I know, how well do I know this, and why do I know it?
1. I first learned that Yellowstone is a National Park because it is a unique geologic area (volcanic caldera) in elementary school when I did a research project on it. I learned more about the geology of the area through the many geology courses I took in college. I also worked on a sedimentology project after college where we were studying the soils in the park: the soils are very erodable and easily impacted by overgrazing of elk and bison and the fires.
2. I lived just north of the park from 1984-1992 and visited the area numerous times. I visited the park for recreation and as part of my job, working with the USFS and Interagency Fire Control. This was when I learned that Yellowstone National Park is part of an expansive mountainous ecosystem. Depending on elevation, one can find alpine tundra, coniferous forest (mostly lodgepole pine), deciduous forest (dominated by Aspen trees), and grasslands. Along rivers and lakes one could find riparian zones, marshes, and shorelines.
3. From Ecology courses in college and subsequent readings, I have learned that Yellowstone National Park is a relatively intact ecosystem with large predators (grizzly bears, wolves, and mountain lions), large herbivores (elk, bison, moose, deer, antelope), and lots of other animals as well. It is unique in that there are no other areas in the lower forty-eight states that have all of these animals. I am not sure what the current thought is about the ecosystem’s health and sustainability.
4. If I am remembering correctly, prior to 1988, there were a lot of trees that were already dead due to beetle kill. I remember that people were talking about how bad it was.
5. I do remember that the drought of 1988 started with a very dry winter followed by a warm, dry spring. Skiing in the region was not very good that year – not a lot of powder but plenty of sunny days.
6. I was still in classes when the first fires started (early June). Some were lightning strikes and some were human-caused. I remember getting a call from the forest’s fire boss about coming to work early. I couldn’t because I needed to take my finals.
7. The smoke from the fires went very high into the atmosphere and spread throughout the region. You could see the plume of smoke from 70 miles away (probably further) and there was no place you could go, locally, to get away from it.
8. From the Ecology courses, fire management classes and working on the lines I remember learning that up until some time in the 1980’s, all the fires in the park and surrounding regions were extinguished as quickly as possible. Fires were seen as “bad”, destroying the forest. In reality, fires play a crucial role in ecology of the area. In the 1980’s, the Park Service adopted the “Let it Burn” Policy, which led to the fighting of the human-caused fires and letting the natural fires burn. The biggest problem with this policy is when the human-caused fires and the natural fires merged; the Incident Commanders didn’t know how to follow the policy. At one point, the fires got so big, we just started protecting the park’s infrastructure.
9. From the Ecology courses and fire management classes, I learned that lodgepole pines and many of the other trees in the YNP system are adapted to fires.
Questions:
1. Was the ENSO a factor in the climatic conditions leading up to the fires?
2. Is there any evidence suggesting that the Yellowstone ecosystem is dominated by large fires and if so, can the “burn cycle” be tied to climatic cycles?
3. What was the impact of beetle-kill on the area previous to the fires? Did this impact the duration and intensity of the fires?
4. What is the current thinking on the Greater Yellowstone Ecosystem, its health and sustainability?
5. What was the difference between the human-caused fires vs. the natural fires in extent, heat, etc.?
6. What were the impacts of the smoke on air quality, both short and long term?
7. How much extra fuel was there due to fire suppression?
8. How did the fires impact soil development and the breakdown of rocks that were exposed at the surface?
9. Were the impacts on the rocks and soil dependent on composition, heat of the fire, slope angle, aspect of the hill?
10. Did the fires affect the quality of the water?
11. How much of the region suffered erosion due to loss of vegetation?
12. What were the long-term impacts on the geomorphology?
13. Are fires important to how landscapes change over time? Could this be specific to the region?
Cycle A - Team
Questions & Answers from Group’s Prior Knowledge
General Information
1. How big were the fires? Somewhere in the 105 acres.
2. How patchy were the fires? Somewhat patchy. The fires burned pretty intensely over the areas that burned. In some places, trees were left standing, mostly around bodies of water where the humidity was higher.
3. What was the difference between the human-caused fires vs. the natural fires in extent, heat, etc.? Not really, except for where they start. Human caused fires are usually along roads, in campgrounds, etc. because of cigarettes and poorly monitored campfires; whereas, natural fires start on hillsides and mountain tops due to lightning. Does this really matter? Well, I think so – since the policy is to fight human-caused fires and let natural fires go.
4. How much extra fuel was there due to fire suppression? It seems like there would be a lot. If fires were being fought in the area since the park was designated, then there would be 100 years of fuel left on the ground. Depending on how many fires would have burned naturally in the area, the amount of fuel might vary from one place to another.
5. What are the long-term costs and benefits to fighting large fires vs. letting them burn?**This is a really good question to have as part of our problem statement. Here are some other thoughts:
Fighting Fires
Costs: Monetary (helicopters, paying fire-fighters, trucks, planes, etc) Water is diverted and used to fight fires. Air is polluted by all the transportation equipment to get the fire-fighters and gear to the site.
Benefits: Jobs and supplying the effort support the local economies
Letting the Fires Burn
Costs: Area becomes less attractive to tourists causing a loss of business to the local economy. Water is more polluted by the runoff. Ash and sediment fill waterways. Smoke and ash fill the skies creating hazardous air conditions.
Benefits: Forest fuels are reduced naturally supplementing the soils and nutrients in the water. Slopes are able to re-stabilize naturally through erosion. Water is not as polluted by the ash and runoff. Air is not as polluted by the smoke.
Fires & the Hydrosphere E > H
6. Did the fires affect the quality of the water? I think ash causes the water to become more acidic. It definitely affects the clarity of the water as ash and sediment is washed into the system. Doesn’t ash also add nutrients to the water thus feeding the macro-invertebrates? How much ash is o.k.? Is there a limit?
Fire & the Atmosphere E > A
7. Was the ENSO a factor in the climatic conditions leading up to the fires? There was an El Nino in 1982-83 or there about. Maybe there is some relation…needs more information here.
8. Is there any evidence suggesting that the Yellowstone ecosystem is dominated by large fires and if so, can the “burn cycle” be tied to climatic cycles? Given that the trees are adapted to fire (serotinous cones, thick bark, root propagation), it seems that there is some evidence that major fires have played a role in the past.
9. What were the impacts of the smoke on air quality, both short and long term? Doubt any long-term problems but definitely short-term.
Fire & the Biosphere E > B
10. What was the impact of beetle-kill on the area previous to the fires? Did this impact the duration and intensity of the fires? Not sure.
11. What is the current thinking on the Greater Yellowstone Ecosystem, its health and sustainability? Not sure. It seems pretty complete and healthy with all the different trophic levels, macrofauna, etc.
12. How many animals and of what kind died? Not sure how many, but it seems likely that some of everything might have died. Yeah, probably more of the little guys though – they can’t outrun things as well. What about the young – it seems like the generation of critters born the spring of 1988 may have really been affected.
13. Did the fires have a long-term impact on the animals and fish? Did that impact how many people visited the area? Not sure.
Fires & the Geosphere E > G
14. How did the fires impact soil development and the breakdown of rocks that were exposed at the surface? Fires increase soil nutrients. Excessive heating and subsequent cooling can cause the rocks to “exfoliate” or spall.
15. Were the impacts on the rocks and soil dependent on composition, heat of the fire, slope angles, aspect of the hill? Not Sure.
16. What were the long-term impacts on the geomorphology? I read something about a woman with the USGS studying this phenomenon. It would make sense that the landscapes of the west had some relation to fires.
17. Are fires important to how landscapes change over time? Could this be specific to the region? See answer to 16.
18. How much of the region suffered erosion due to loss of vegetation? I worked on a project that collected some data and mapped out mass movements related to the fires. I don’t remember how much was affected but there was definitely some. There are always landslides and debris flows associated with the fires in Southern California.
Research Plan:
The following people will tackle the above questions –
• Andy: General Information
• Cheryl: Fire & Geosphere
• Mark: Fire & Atmosphere
• Lynn: Fire & Biosphere & Hydrosphere
We need more specific answers with data and evidence to support. Let’s investigate both Governmental sources as well as NGOs and science journals/websites. By the end, we should have a good sense of how natural fires in Yellowstone have operated in the past and how they are different from human-caused fires. From there, we should be able to complete a more comprehensive cost-benefit analysis of fighting or not fighting YNP wildfires.
Problem Statement:
Fires are a natural part of the Greater Yellowstone Ecosystem. That ecosystem evolved with fires and fires continue to be a tool that land managers may need to use to keep the ecosystem in balance. However, because of human incursions into the natural ecosystem, there is a limited amount of forage, space, and fresh water for the wildlife in the area. Fighting fires may be necessary to keep the ecosystem intact and functional.