Source #1: Resilience to Large, “Catastrophic” Wildfires in North America's Grassland Biome

 

Citation:

 Donovan, V. M., Twidwell, D., Uden, D. R., Tadesse, T., Wardlow, B. D., Bielski, C. H., Jones, M. O., Allred, B. W., Naugle, D. E., & Allen, C. R. (2020). Resilience to large, “catastrophic” wildfires in North America’s grassland biome. Earth’s Future, 8(7). https://doi.org/10.1029/2020ef001487

 

Summary Content

 

Who are the researchers?

• All researchers except two, are assistant professors at the University of Nebraska in the Agronomy and Horticulture department with three of them in the National Drought Mitigation Center, School of Natural Resources, University of Nebraska

• The other two researchers are assistant professors at the W.A. Franke College of Forestry and Conservation, University of Montana

 

What was the purpose of the study? 

Wildfires across the US are rapidly increasing and their effects on vegetation over a wide-scale area aren’t widely known. This research covers the grassland biome in North America, The Great Plains. The researcher's goal is to determine the large-scale vegetation response to wildfires. Theres no information suggesting that wildfires cause extensive harm to vegetation in the biome. Many other studies investigate the benefits of fire on a vegetation. This study looks at the effects large wildfires have on a biome and the effects on vegetation as well as the ecosystem services this biome produces.

 

Participants/Subjects: 

The researchers are looking at all major widespread wildfires in the Great Plains, an area of dry climate in the middle US, greater than 400 hectares from the years 2000 to 2018. They look at “functional vegetation”: trees, shrubs, annual forbs (flowers) and grasses, and perennial forbs and grasses. This area experiences various drought conditions and it includes all of the functional groups they wanted to study over this period.

 

What methods were used in the study?

Land cover vegetation data that covers seven land cover classes in the Western US was sourced and used to see the annual forbs and grasses, bare ground, litter, perennial forbs and grasses, rocks, shrubs, and trees. In this study, only five of the classes were looked at since they excluded litter and rock cover. Using the Monitoring Trends in Burn Severity (MTBS) database they chose large-scale wildfires larger than 400 hectares. They used the Monthly Palmer Drought Severity Index (PDSI) data to help determine the severity of the fires. Study regions were determined by the Environmental Protection Agency's ecoregion boundaries. The Great Plains were divided by level three ecoregion boundaries. This simply means that the regions used had similar ecosystems and vegetation.

 

What did researchers find?

Vegetation in functional groups showed an immediate response to wildfire. The responses were very strong and could be seen across the Great Plains. Perennial forbs and grasses showed the fastest land cover decrease while burns on bare ground saw an immediate increase in land cover. Tree cover decreased rapidly after but compared to other reduced cover vegetation was the least. The shrub cover increased immediately after as well. Soil conditions caused variations in the decline of vegetation, the perennial forbs and grasses showed very different land cover levels depending on soil moisture. While changes were caused imminently after the fires, no persistent changes were noted in any functional group, all conditions either stayed the same or returned back to how they were before the fire. This doesn’t support their initial thoughts but good and valuable data was still found. This study is filled with tons of tables and graphs to show all the data collected, it’s a very nice visual to see the changes and returns.

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Source #2: Recent post-wildfire salvage logging benefits local and landscape floral and bee communities.

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Citation:

 Heil, L. J., & Burkle, L. A. (2018). Recent post-wildfire salvage logging benefits local and landscape floral and Bee Communities. Forest Ecology and Management, 424, 267–275. https://doi.org/10.1016/j.foreco.2018.05.009

 

Summary Content

 

Who are the researchers? 

• Laura J. Heil

  • Research assistant at Montana State University

  • Research assistant at Saint Michael’s College

  • Department of Ecology

  • Educated in Environmental Science and Ecology

• Laura A. Burkle Ph.D.

  • Professor and researcher at Montana State University

  • Director of Conservation Biology and Ecology Program

  • Pollinator Health Center at MSU

  • Montana Institute on Ecosystems

 

What was the purpose of the study? 

This research experiment is about how logging in areas soon after a wildfire can positively affect the growth and abundance rates of wildflowers and bees. Not much research has been directly done on this topic so it is hard to compare their research to others. This is also a reason as to why they conducted this experiment. Some of their sources mention more diversity of pollinators due to the forest canopy being gone. They are wanting to see how post-burn logging affects the alpha and beta diversity of flowers and bees specifically, and how those populations are correlated to various variables after the burnt timber is taken away.

 

Participants/Subjects:

The areas are abundant with many plants, mostly, Pseudotsuga menziesii, Pinus contorta, Picea engelmannii, and Abies lasiocarpa. Logging in Thompson Creek happened in 1993 with 177 total acres cleared and in Wicked Creek, 2008, 654 acres were cut. Within each fire perimeter, there was a 15-hectare lot that was logged and a 15-hectare lot that was unlogged, here is where the experiment took place. Bees, flies, butterflies, and beetles were of the 152 different species of pollinators that were sampled. There were also 739,250 different flowers and forbs that made up 236 species.

 

What methods were used in the study?

In the Gallatin National Forest in Montana, the sites of two different wildfires were chosen. Burned areas were: Thompson Creek (6,979 acres) in 1991and the Wicked Creek (22,159 acres) in 2007. These two fires were chosen because they had very similar effects and credentials. The researchers decided to collect data once a week for two growing periods during the peak season which is from June 1st to August 21st. Plant species were only counted if in bloom due to flowers being bee’s resources. Pollinators were captured by hand nets, then put into vials and put on ice before returning to the lab for observation. This ensured that they were fresh and able to get the best information from the live samples taken. Sites were combed in a random order on warm, sunny, and calm days. Sample collecting lasted 3.7 hours a day.

 

What did researchers find?

This research showed that logging immediately after in post-fire areas did positively influence pollinators (bees) and local flora densities. In areas that look longer to log (Thompson Creek), density percentages were 28% lower. While in the location of the younger fire (Wicked Creek) where logging happened sooner, floral densities were up 39%. In the area of the older fire, there was no difference in the densities of both variables in both plot locations, logged and unlogged. The newer fire location did show different densities, 23% higher in logged than unlogged. Charts embedded in the data show a very good visual of all the data laid out. Results explain that good can come out of wildfires, the positive results regarding bees are extremely exciting to hear about too!

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Source #3: Short- and long-term effects on fuels, forest Structure, and wildfire potential from prescribed fire and resource benefit fire in Southwestern forests, USA

 

Citation:

 Hunter, M. E., Iniguez, J. M., & Lentile, L. B. (2011). Short- and long-term effects on fuels, forest structure, and wildfire potential from prescribed fire and resource benefit fire in southwestern forests, USA. Fire Ecology, 7(3), 108–121. https://doi.org/10.4996/fireecology.0703108

 

Summary Content

 

Who are the researchers? 

• Molly E. Hunter

  • Associate Research Professor at Arizona State University

  • Specializes in applied fire science and wildfire fuel management

  • Educated in Plant Biology (B.S.) and Forest Science (PhD)

• Jose M. Iniguez

  • Research Ecologist for the Forest Service at the Rocky Mountain Research Station

  • Educated in Forestry (B.S. and M.S.) and Natural Resources (PhD)

  • Focuses on fire impacts in forested areas

• Leigh B. Lentile

  • Forest Ecologist

  • Educated in Natural Resources and Forest Sciences

  • Associate Professor at the University of The South

  • Department of Forestry and Geology

 

What was the purpose of the study?

This study looks into the effects of prescribed fires, also known as controlled fires, carried out by professionals used to mitigate the effects of wildfires in the Southwestern US, The researchers also look into the effects of resource benefit burns which are naturally occurring fires that don’t get contained by an organization and are allowed to spread within a perimeter. These fires can occur year round and are becoming more abundant due to climate change. Wildfires are becoming more abundant due to climate change, we can't fully manage climate change but we can manage wildfire fuel, the brush, and dry woody plants that burn fast in a wildfire. Research done to help with fuel management hasn't taken into consideration the topography and lack of timber industry in this region. Many questions still remain unanswered by other research including how the different types of fuel are burned and left behind. Theres also research gaps between pre and post-fire conditions with other researchers. Most researchers tend to focus on pre fire areas or post fire effects.  

 

Participants/Subjects:

The researchers looked into The Gila National Forest in New Mexico. The vegetation they studied included those places dominated by ponderosa pine, pinyon pine, various juniper species, and oak tree species. They chose this National Forest because it has historically used fire as a restoration tool. The forest gets around 300mm to 380mm of precipitation a year, half as snow in the winter and the other as rain in the summer. The researchers are looking into the impacts different types of fire has on these plants in their dominated areas of the forest.

 

What methods were used in the study?

In the Gila Nation Forest located in New Mexico, the researchers randomly established 0.02-hectare plots in areas with recent prescribed and resource-benefit fires have occurred. This forest was chosen as the location of this research project because the land here has been used for prescribed burning in the past. Areas of research were chosen if they had not been previously thinned and plots were randomly separated into stratified stands to be surveyed. One plot was selected in the middle of the stand. Burn severity of the stand and plot was determined by using the Burn Area Emergency Response data on its website. High burn severity is low in the area so medium and high were combined into a moderate ranking level. Pinyon-juniper woodlands burn mostly low- severity and are somewhat rare in this area so this section of research focuses on low-burn ponderosa pine forests. Ten plots of the ponderosa pine areas surveyed had experienced three fires and 20 plots in the area had experienced two fires. There were unburned plots adjacent to the burned areas to use as comparison sites. In the area of the plots live and dead trees were tallied and measured in various positions. The plots composite burn index (CBI) was then created, this only applies to the burned areas of the plots.

 

What did researchers find?

Results of this research show that low burn severity resource benefit fires had more of an effect than prescribed fires. Both resource-benefit and prescribed fires have proven to be low burn severity but resource-benefit burns have a slightly higher CBI rating than the latter. This means they have more burned areas. The burn strategy or severity was said to not have a significant effect on surface wildfire fuels and there wasn’t a high difference between the time spans of the burnings. Understory vegetation coverage had a very high burn rate and a significant difference from the control in both burn-type cases. Dead and fallen leaves and branches as well as grasses burn faster than green leaves and tall trees. In pinyon-juniper woodlands, the CBI was higher and classified as moderate severity burning. Results prove what the researchers thought about the different burn severity types correlating to the types of vegetation and weather conditions present. Tables displaying all of the data make the results easy to read and understand. This information can and will help in the changing natural world due to climate change, knowledge of these burn types and severities makes it so better wildfire fuel management can be created to help timber in the southwestern US.