Category Archives: Ask an Expert

Ask an Expert | Fire and the Great Plains

Large wildfires are becoming more frequent on the Great Plains, driven, in part, by more woody vegetation. This photo shows eastern redcedars burning on the Carr Ranch during the Anderson Creek wildfire.


Fire has long played a leading role shaping the ecology of the Great Plains. Whether lightning-caused or human-induced, research shows that much of the Great Plains experienced fire frequently, every fourteen to less than two years depending on region. Recurrent fire helped create and maintain the diverse grassland ecosystems – short grass, mixed grass and tallgrass prairies – that exist across the Plains. Fires also controlled woody species presence throughout the region, confining trees and shrubs to sites where fire was less frequent or absent due to topographical, climatic, or other natural conditions.

Over the last couple of centuries, the removal of indigenous fire ignitions and widespread fire suppression throughout the region drastically altered this historic fire regime. In a short period of ecological time, the Plains went from one of the most frequently burned regions on the planet to one where fire became relatively scarce, allowing woody species and associated fuel loads to build and expand. Today, wildfire, specifically large, damaging wildfires, have greatly increased in frequency and severity across the Plains. The 33 documented large wildfires that burned in the Plains from 1985 to 1994 have been eclipsed by 117 large wildfires that burned in the next 10 years (2005-2014).

Woody expansion is causing a shift from grasslands to woodlands in central North America, and this shift is collapsing wildlife diversity, heightening wildfire risk, and crashing grazing land profitability. In short, woody expansion is threatening the very characteristics that make the Great Plains so productive.

Fires that deter woody expansion are driven by complex interactions between climate, fuel loads, land use, and human behavior. Dr. Victoria Donovan and her team of researchers at the University of Nebraska are at the cutting edge of understanding the various roles of fire as a driver of plant community change in central North America. We sat down with Dr. Donovan to learn more from her two new papers: Land-Use Type as a Driver of Large Wildfire Occurrence in the U.S. Great Plains and Resilience to Large, ‘Catastrophic’ Wildfires in North America’s Grassland Biome.


These two papers focus on fire in the Great Plains. Scientists have concluded that fire was once a regular part of the Great Plains ecosystem, but that’s no longer the case. Why were you and the team interested in studying large wildfires in the Great Plains?

While we know that large wildfires have been increasing substantially across forested regions of the western U.S. for some time, recent increases in large wildfire are relatively new in the Great Plains. This offers us the opportunity to understand shifting wildfire patterns in this region and possibly get ahead of some of the risks large wildfire can pose to people by learning how to better manage wildfire to prevent loss of human life and property.

Let’s start with the paper called Land-Use Type as a Driver of Large Wildfire Occurrence in the U.S. Great Plains. Your team analyzed large wildfires in the Great Plains from 1993 to 2014 and overlaid the boundaries of those fires onto a map. You then analyzed the various types of land use, which you classified into five types – grassland, woody vegetation, cropland, pasture and hay fields, and developed areas – within the fire boundaries. What were you looking for?

We wanted to understand how land use might be playing a role in shifting wildfire patterns by identifying which land-use types have the highest propensity for wildfire. Around the world, different land-use types, including agricultural and developed lands, are known to affect wildfire occurrence differently. Over the last century, the Great Plains has seen drastic shifts in land-use following Euro-American settlement, including agricultural conversion and development, along with widespread woody encroachment of grassland systems. Today’s wildfires are occurring within that altered landscape. Since our previous research showed a surge in wildfire activity in the Great Plains, a clear question for us was to determine whether this surge was tied to different land uses.

You note that in 11 of the 14 ecoregions you analyzed: “areas burned by large wildfire were primarily composed of woody vegetation and grassland.” Why are these land-use types more susceptible to large fires?

There are a number of reasons why we saw more fires in these land-use types. Grasses are one of the most flammable fuel types on the planet, and they are highly adapted to and have properties that promote frequent fire. While woody vegetation communities do not typically experience fires as frequently as grasslands, they offer an abundance of fuels that promote large fires once ignited. In contrast with grasslands, vegetation in pastures, hay fields, and crops generally have different fuel properties that make them less susceptible to fire. For instance, the plants in these areas tend to hold more moisture, which can make it much more difficult for fire to ignite and spread. Irrigation could also play a role in this. This result is consistent with research that suggests that crop fields may actually act as a barrier to fire spread in some regions of the world, which is interesting since we know that agricultural lands are some of the most frequently burned land use types elsewhere in the world. There are social reasons as well. For instance, fire suppression is more likely to be successful for a wildfire burning through a grassland than one burning through forest canopy.

Dr. Donovan’s team found that grasslands and woody vegetation are the land-use types with the highest propensity for large wildfires. Figure courtesy of Dr. Donovan.

It makes sense that intact grasslands burned more than crops or developed areas, but you found that woody vegetation “burned proportionately more than any other type of land-use in the Great Plains.” What do you mean by that and why is it important?

We found that of all of the land-use types in the Great Plains, large wildfire is most likely to burn in woody vegetation. This means woody vegetation is associated with the highest large wildfire risk. This is extremely important because we know that woody vegetation is increasing across much of the Great Plains by invading our grassland systems. We also know that wildfires that occur in woody vegetation are generally more difficult for us to put out. Consider a campfire: You might use a few handfuls of dried grass as a way to get the fire started, but if you don’t add some logs to it, it will burn out quickly. The same is true in natural systems. Woody vegetation generally offers more fuels that can burn longer and more intensely than grasses. To add to that, trees grow much taller than grasses. Imagine trying to put out your campfire when it is a few stories above you.

We know many grasslands are transitioning to woody vegetation in the Great Plains because we have removed the frequent fires that used to burn through grasslands. We also know that tree planting is a common practice across much of the Great Plains and these have served as seed sources for invasion into more intact grassland systems. What our results suggest is that if we continue to promote woody vegetation across the Great Plains, we are also going to be increasing our risk for large wildfires that are more difficult for us to control.

Woody vegetation is the most likely type of land use to burn in the Great Plains. Figure courtesy of Dr. Donovan.

Let’s shift gears to the second paper called Resilience to Large, ‘Catastrophic’ Wildfires in North America’s Grassland Biome. Will you explain what you mean by “resilience”?

Resilience is the amount of change that an ecosystem like a grassland can experience before shifting into something else, like a desert. When we were considering resilience in this study, we were tracking whether vegetation cover in an ecosystem was able to recover following wildfire or transition to an alternative type of ecosystem. For example, we wanted to know whether grass cover recovers to the same level as before the wildfire or whether a different vegetation type takes over after wildfire.

So, your team examined how the landscape, and specifically how the vegetation community on that landscape responded to large, severe wildfires. First off, how did you find the information and data you analyzed? Secondly, what did you find?

We were lucky enough to gain access to an amazing new data set from the Rangeland Analysis Platform, a project led by researchers from the University of Montana in collaboration with the Bureau of Land Management and the Natural Resources Conservation Service’s Working Lands for Wildlife team. It provided us with information on vegetation cover across much of the Great Plains that hadn’t been available over such large areas before. What this meant was that we could ask questions about the outcomes of large wildfires on vegetation across vast extents of the Plains to gain a fuller picture of wildfire in this region.

While we know that fire was historically an important part of the Great Plains, there is also concern in this region that fire can cause irreversible changes to vegetation. For instance, there are a number of programs that promote re-seeding following wildfire to prevent desertification, that is, the conversion of a vegetated area to bare ground. What we found was that the Great Plains is highly resilient to wildfire. At the biome level, all vegetation returned rapidly to pre-fire levels. In every ecoregion, we saw rapid recovery of perennial and annual forbs and grasses. Our findings echo over a century of research demonstrating grasslands in the Great Plains are highly resilient to wildfire.

The researchers found that perennial vegetation cover came back quickly following fire and that bare ground returned to pre-fire levels just as quickly. Figure courtesy of Dr. Donovan.

Was there one vegetation community or one location within the Plains where fire did cause a long-lasting change in the type of vegetation cover?

Yes, in the northwestern Great Plains ecoregion we saw persistent decreases in tree cover following wildfire over our study period. This helps confirm findings from more localized studies that indicate that fire has the ability to control and remove woody vegetation in some rangeland systems. The northwestern Great Plains is dominated by ponderosa pine trees, which can be rather fire sensitive compared to some re-sprouting species in the southern Great Plains, like mesquite.

In the Northwestern Great Plains, the researchers found that tree cover decreased following fire. Figure courtesy of Dr. Donovan.

Does drought play a role in how vegetation responds to wildfire?

We found that drought can amplify the immediate response of vegetation to wildfire. For instance, if a wildfire occurred under more severe drought conditions, there was generally a greater initial loss in perennial forbs and grass cover. However, we didn’t find that drought had any impact on long-term losses of vegetation cover. In other words, wildfires burning under more extreme drought conditions did not impact the probability of vegetation recovery, though recovery may take longer than if wildfire had burned under moist conditions.

Your team found that woody vegetation burns disproportionately more often than other land-use types, and that in some places it is the one vegetation community that is least likely to return. Given that encroaching woody species have a negative impact to water, wildlife, and other resources on the Great Plains, that seems like it could be a good thing for rangelands. Is that the case?

BLM wildlife biologist Randy Howard lights a prescribed fire on the Sand Ranch in eastern New Mexico. Prescribed fires reduced fuel loads on the land, which in turn reduced the spread of the East Cato wildfire in July 2017.

Yes and no. For wildlife and vegetation that depend on a prairie environment, wildfires can provide a pathway for re-gaining rangeland lost to woody vegetation. In fact, some landowner groups in the Great Plains and elsewhere have viewed wildfire as a restoration mechanism that can be used as a launching point to prevent the re-establishment of problematic woody species like Eastern redcedar. On the other hand, we know that large wildfires can pose a risk to human communities, particularly, when they occur in more volatile woody fuels. How do we balance that? We utilize prescribed fire. The Great Plains was one of the most frequently burned regions in the world historically (with some locations burning every two years or less). Vegetation in the Great Plains has a long history of thriving with fire, which our research helps to emphasize. Frequent applications of prescribed fire is an effective way to help reduce wildfire risk while re-integrating an important ecological process into grassland ecosystems.

 

 

What are the key takeaways that you want people to understand from your papers?

  1. In the Great Plains, our grasslands are able to recover rapidly following fire, even under extreme drought conditions.
  2. Removing fire from these systems may have inadvertently increased the risk of large wildfires by allowing woody encroachment.
  3. Using fire as a management tool could help reduce large wildfire risk in some regions by reversing and preventing further woody encroachment.

Meet the Expert

Will you tell us a bit about your research interests and what you’ll be focusing on next?

Dr. Victoria Donovan is a researcher at the University of Nebraska, Lincoln. Photo courtesy of Dr. Donovan.

 

I am really interested in understanding how processes like fire structure and shape ecosystems. In this rapidly changing global environment, I think understanding this will be key to building ecosystem resilience and managing ecosystems that we depend on. I have a background in wildlife research, so I am hoping to take the findings that I have learned here and integrate them with wildlife data to get a better picture of how animals, plants, and processes like fire shape one another and how we can use these interactions to plan for and adapt to future change.

 

What keeps you busy when you’re not working on a research project?

I am big into travel. I love to explore the wilderness of different countries, learn about new cultures, and try new and delicious foods. While I am saving up for my next trip, I am camping, hiking, kayaking, and volunteering with my local animal shelter or youth organization.

Cake or pie?

Definitely cake and preferably chocolate.

Scientists using telemetry

Ask An Expert | The Science Behind Private Lands Conservation—A Conversation with Dr. Dave Naugle, Working Lands for Wildlife Science Advisor

Scientists using telemetry

Outcome-focused science plays a key role in Working Lands for Wildlife’s approach to conservation on private lands. Photo: Kenton Rowe


The Lesser Prairie-Chicken Initiative (LPCI) is part of the USDA-Natural Resources Conservation Service’s Working Lands for Wildlife efforts – nationwide initiatives focused on conserving and restoring working agricultural lands to benefit wildlife and watersheds while also improving ranch and farm productivity. The Sage Grouse Initiative (SGI) is another Working Lands for Wildlife (WLFW) effort focused on the sagebrush ecosystem of the Intermountain West.

Working Lands for Wildlife takes a team approach to conserving western rangelands: NRCS leadership ensures Farm Bill funding is used efficiently and effectively to improve western rangelands for healthy wildlife, water, air and plants, and for the rural communities they support. Local NRCS staff and the LPCI’s Strategic Watershed Action Team (SWAT) work with private landowners to implement conservation practices like sustainable grazing systems, mesic habitat restoration, conifer removal and prescribed fire. Partners, like Pheasants Forever and The Nature Conservancy, leverage funding and resources to do more work across the West. It’s a great model that has allowed the LPCI to work with more than 800 landowners and to conserve more than 1.6  million acres of the southern Great Plains since 2010.

But there’s another group of people behind the scenes who play an integral role in WLFW’s work: A team of working lands scientists. Since its inception, WLFW and in turn, LPCI and SGI, have been science-driven efforts. The opening page of LPCI’s website notes that “LPCI-funded research ensures we’re doing enough of the right things in the right places to achieve our conservation goals.”

Dr. David Naugle. Photo courtesy of Dr. Naugle.

Long-time WLFW Science Advisor and University of Montana wildlife professor, Dr. David Naugle, helps lead the western WLFW science team. Dr. Naugle recently published a paper in the prestigious journal BioScience entitled Coproducing Science to Inform Working Lands: The Next Frontier in Nature Conservation. This new paper champions both the importance of working lands in conservation and the role for science in achieving better outcomes for ranching and wildlife.

We sat down with Dave to learn more about the critical role science plays in WLFW’s approach to conservation.

 


Why your intense interest in working lands conservation?

I spent my early career working on public lands policy but now find myself fascinated by working rangelands as global productivity centers, biodiversity hotspots, and the glue that holds together public lands. The father of modern conservation, Aldo Leopold, taught us that “conservation ultimately boils down to rewarding the private landowner who conserves the public interest.”

Public lands are a cornerstone of American culture but it’s the privately-owned working lands that hold the key to maintaining conservation-reliant species for which persistent threats cannot be eliminated but only actively managed. Reinvesting in these rural communities is the best way I know to keep intact grazing lands from being swallowed up by cultivation, subdivision and energy developments.

Your paper is called Coproducing Science to Inform Working Lands: The Next Frontier in Nature Conservation. What is coproduction and how does it differ from other approaches to science?

Simply put, coproduction of knowledge is a way of making science more actionable by engaging with stakeholders to share in both study design and implementation. And surprise, surprise…people are more apt to incorporate new information into their way of thinking if they are invested upfront in its production. So, the goal of coproduction is to achieve better outcomes for society by engaging more people earlier in the science process and thereby increasing the utility of science in decision-making and practice.

Notably, the recent popularity of coproduction in health care with patient and public involvement is leading to better outcomes. If widely adopted for working lands, coproduction could provide participants with the necessary knowledge to better sustain rural livelihoods and nature’s resources on privately managed rangelands, forests, and cultivated lands that collectively occupy 80% of the world’s terrestrial area.

Outcomes are all the rage today in conservation; what is an outcome?

Merriam’s dictionary defines outcomes as: “something that follows as a result or consequence.” In other words, an outcome is the upshot, or the way a story turns out. In contrast, outputs simply describe the amount of conservation produced, which are typically reported as acres enrolled, miles managed, or dollars allocated. Outcomes are superior to outputs because they quantify the impact of conservation efforts.

For example, the SGI’s efforts have resulted in the following outputs: 11,000 square miles of sagebrush grazing lands restored or enhanced on more than 2,000 ranches since 2010. While such outputs are large, even more impressive are resulting outcomes including +12% higher sage grouse population growth within conifer management in Oregon, +25% greater vegetation productivity for ranching and wildlife following riparian and wet meadow restorations in Nevada, Oregon and Colorado, and 75% of priority habitats conserved for two migratory mule deer herds through measures enacted to protect sage grouse in Wyoming.

If I’ve learned anything over the years it’s this…having coproduced outcomes makes it way easier to tell your conservation story. Outcomes also provide partnerships with a mechanism for sustained funding by articulating return on investment to stakeholders. Looking back, the 2015 ESA decision was a major testing ground for the utility of outcomes in evidence-based conservation. Turns out the U.S. Fish and Wildlife Service cited SGI outcomes 43 times in their determination to not list sage grouse as an endangered species.

Has your coproduced science ever failed to support a highly anticipated outcome?

Oh, yeah, it really happens. Such was the case when a seven-year assessment showed that pastures rested from domestic grazing did not increase sage grouse nest success. Despite dogmatic support in the literature, the hypothesized benefits of herbaceous hiding cover never materialized at pasture- and ranch-level scales in which herbaceous cover was experimentally manipulated. In response to our findings, the NRCS adjusted delivery of conservation practices to de-emphasize financial incentives being paid for extended rest within rotational grazing systems.

WLFW’s Science to Solutions series highlights new research in a clear, practical manner.

These results spawned additional inquiry challenging the long-held belief that grazing restrictions inevitably benefit sage grouse populations. Follow-up study revealed that commonly used methodologies were inherently biased, misrepresenting the relationships between habitat structure and sage grouse nest success. These results initiated a third line of questioning to understand the economic implications of the unintended habitat loss on private land resulting from grazing restrictions placed on publicly adjacent rangelands. Collectively, this string of coproduced science is raising the collective appreciation of the more complex interrelationships between wildlife habitat and ranching enterprises in this public–private checkerboard of land ownership of the Western U.S.

Why is Working Lands for Wildlife science unique?

Unique maybe; laser-focused…always! As the science arm of WLFW, we do two things— 1) develop spatial targeting tools to pinpoint where to invest in conservation, and 2) evaluate whether resulting investments yield desired outcomes. The USDA and our partners know that limited resources necessitate a strategic, landscape-scale approach that replaces random acts of conservation kindness to increase the odds of achieving desired outcomes.

Versed in coproduction, our science team knows well the painstaking preplanning and delayed gratification that accompanies doing science alongside real, watershed-scale conservation. We often jest that science chases implementation because of our partners’ appetites for access to coproduced science, online tools and additional outcome-based evaluations.

For example, it took us ten years, two PhD students and a boatload of radio-marked birds to confidently say that conifer management increases sage grouse population growth by +12%. From a science perspective, quantifying this level of population response is almost unheard of in wildlife management, and I hope this new knowledge gives managers the confidence to continually scale up this beneficial practice. Is it easy? No. Is it worthwhile? Absolutely.

What do you value most with your involvement with working lands science?

We science folks can be a flighty bunch, chasing personal research interests and jumping from one funding opportunity to the next. But I’m a long-term investor who believes that it takes time to develop a meaningful program. The tendency for science to be paid for and published, but then left on the shelf for someone else to find and use is no longer a defensible approach. To quote Wes Burger, a private lands scholar and colleague at Mississippi State University, ‘science should be done with the intent to deliver conservation actions, and delivery should be done with the intent to measure outcomes.’

Also, and this aligns with the concept of coproduction, the WLFW team does a good job of making all the science we produce accessible to multiple audiences. A recent report from the University of Wyoming’s Ruckleshaus Institute titled “Developing a social science research agenda to guide managers in sagebrush ecosystems” (2019) noted: “One communication model highlighted by multiple participants is the Sage Grouse Initiative’s (SGI) Science to Solutions program, which multiple participants felt was an effective strategy for reaching a diverse array of stakeholders.” I think that’s pretty great. That same report also stated that: “Participants emphasized the importance of trust and relationship building on behalf of social scientists and decision makers and identified the Sage Grouse Initiative as an example of a trusted source of information that has had some success in influencing sagebrush conservation and management decision making.”

So, if I had to put my finger on one thing that makes Working Lands for Wildlife special, it’s the direct pipeline between science and conservation. The speed at which new knowledge is incorporated into on-the-ground conservation is amazing; once you experience this as an applied scientist you’ll never go back!

Where is the science arm of WLFW headed next?

RAP

The powerful Rangeland Analysis Platform is revolutionizing rangeland management.

We’re diving headfirst into expanding conservation using our new Rangeland Analysis Platform or RAP. The RAP is the brainchild of Brady Allred our rangeland ecologist here at University of Montana. It fits our philosophy wherein coproducing scientists provide partners with state-of-the-art mapping technologies who, in turn, implement well-placed practices to further scale up beneficial outcomes.

And as word spreads, neighboring watersheds are hungry to employ this tool (and others) in their backyards. Idaho is using RAP-based invasive annuals mapping to craft their Cheatgrass Challenge knowing that weed control is most effective when management is informed by what’s going on in the surrounding landscape. On the horizon for the RAP are jam sessions with USDA to evaluate pipelines for these web applications to be used more broadly across the Department.

Lastly, the upcoming launch of our newest RAP functionality will evaluate biological and economic strategies to help partners get ahead of woodland expansion on grazing lands across the western U.S.

Does your crystal ball show a bright future for working lands conservation?

There is no doubt in my mind that we are entering a ‘Renaissance-type Era’ for private lands conservation that will rival our response to the Dust Bowl. Landowner-led and collaborative partnerships will show us the way with much leadership already in place (e.g., Blackfoot Challenge, Malpai Borderlands Group, Tallgrass Legacy Alliance, Sandhills Task Force, and many more). Local landowner leaders hold much of the deeply rooted trust and credibility necessary for the longevity of resulting conservation.

Equally important is the advancement of like-minded, landowner-led groups such as Western Landowners Alliance and Partners for Conservation that are coalescing into umbrella organizations to extend their shared vision of working lands conservation into additional watersheds. The only real question now is one of further coordination and support so that we’re all pulling in the same direction.

Any closing thoughts beyond coproduction?

Yeah I have one that keeps me up at night…as conservation professionals we ought to ask ourselves if we’re properly equipping the next generation in working lands conservation. The public recognizes the Farm Bill as one of the most globally powerful tools in conservation. Neighboring countries envy us for it, yet its depths are poorly understood locally, and unknown to most of the generation in training.

Working with young scientists on private lands conservation is critical for the future of the field.

I often play the acronym game with wildlife students in class; they all know BLM, FWS and USFS, but most blankly stare back when I quiz them on NRCS. We need to change that to effectively deliver conservation on private lands at watershed scales.

But even when I start to worry, I’m reminded of rapid change on this front too. For example, Lowell Baier’s new book entitled Saving Species on Private Lands, due out in April, serves as a Farm Bill roadmap for landowners, and as a first to my knowledge, Colorado State University is advertising a Professor of Working Lands position.

Meet the Expert

What book are you currently reading?

Don’t be Such a Scientist (2018) by Randy Olson, and anything else I can get my hands on to make me a better communicator with non-science audiences—have to admit, I’ve become a bit obsessed the last couple of years.

What is your favorite non-academic activity?

Family, family, family. Travel hockey with our son is the focus for weekends now through March. I’m having a blast watching my daughter finish up undergraduate here at UM before heading to PA school next year. My wife and I are travel junkies that love investigating different corners of the world—next up, Norwegian fjords.

And finally, you got your MS and PhD from South Dakota State but now work at the University of Montana. Who do you root for?

Oh gosh…ok, picture this, how about a ‘Go Griz’ hoodie overtop my ‘Get Jacked’ SDSU t-shirt on game day when Jacks battle Griz on the gridiron in UM’s Washington-Grizzly stadium!


Why You Should Know About the Eastern Redcedar Science Literacy Project

This isn’t how America’s Great Plains are supposed to look.

The Western Working Lands for Wildlife initiatives like the Lesser Prairie-Chicken Initiative (LPCI) and the Sage Grouse Initiative (SGI) focus on the concept of rangeland resiliency. In short, rangeland resiliency is the capacity for rangeland to absorb “disturbance,” like drought or fire, without becoming degraded. Resilient rangelands continue to function in the face of disturbance, or they bounce back from periodic disturbances and quickly return to healthy, productive ecosystems after their initial collapse. Rangelands that lack resiliency struggle to recover from disturbances, do not return to their pre-disturbance structure and function, and instead transition to an alternative state that is often less desirable for both agriculture and wildlife.

In the West, Working Lands for Wildlife works to improve rangeland resiliency on private lands across the prairies and grasslands of the Great Plains and the 11 states with sagebrush-steppe landscapes. Many challenges threaten rangeland resiliency in this huge region. Conversion of productive grasslands or sagebrush-steppe to closed-canopy woodlands is one of the biggest ones.

Trees are, of course, historic residents of the West. But over the last 150 years, conifer trees have expanded from their historic range into previously tree-less landscapes. In the sagebrush-steppe, juniper trees are the main culprit. In the Great Plains, Eastern redcedar is perhaps the most notorious example of a native tree turned invasive, and it’s moving into new territory at an alarming rate. Nebraska is now at the front lines of cedar invasion: nearly half a million acres of grazing lands have been lost since 2000 because of expanding redcedar forests.

Across all of the regions, this change is creating numerous impacts.

  • As conifers encroach on grasslands and sagebrush-steppe, wildlife like the lesser prairie-chicken, the greater prairie chicken, and the greater sage grouse move out. Research by SGI and LPCI has shown that as few as one to two trees per acre will cause the birds to leave.
  • Grasslands and sagebrush-steppe are remarkably diverse ecosystems. As they change into forests, much of that biodiversity is lost, and native grassland- and sagebrush-dependent species are negatively affected.
  • Trees use more water than the native plants in prairies and sagebrush range. The trees suck up water that is no longer available to native plants, aquatic life, agriculture, and communities.
  • Woody species also increase the negative impacts from wildfires. The trees fuel more intense wildfires, which impact wildlife, encourage invasive weeds, stress communities, and more.

Nebraska is on the front lines of an eastern redcedar invasion as illustrated by this photo from the Loess Canyons area. Photo by Dirac Twidwell, UNL

One of the leading researchers on the impacts these trees are having on the Great Plains is Dr. Dirac Twidwell of the University of Nebraska-Lincoln. In addition to his research efforts, Dr. Twidwell is also the Associate Director for the new Center for Resilience at the University of Nebraska.

Dr. Twidwell and his colleagues at UNL launched the “Eastern Redcedar Science Literacy Project” in a two-part effort to study the impacts of Eastern redcedars and other conifers and to share their findings with the public. We sat down with Dr. Twidwell to talk about his research, the Project, what this threat means for wildlife and humans, and what land owners and managers can do about it.


Will you start by introducing the Eastern Redcedar Science Literacy Project? What is it? When did it start?

The Eastern Redcedar Science Literacy Project (ERCSLP) is the most comprehensive resource for understanding the spread and impacts of Eastern redcedar, one of the most well-studied and problematic invasive species in North America. I want to acknowledge the contributions of all the researchers and graduate students who helped create the ERCSLP, especially Christine Bielski, a graduate student who led the project’s development.

The project started in response to the increasing demand from private citizens and natural resource professionals for more information on the consequences of the Eastern redcedar invasion. As we studied these impacts, it became increasingly clear that the general public was unaware or ill-informed about the breadth and depth of science related to Eastern redcedars.

ERCSLP homepage image

The Eastern Redcedar Science Literacy Project website is a one-stop-shop for the most up-to-date eastern redcedar science and research.

What was your motivation for creating the project? What are its goals?

As a scientist, I increasingly feel an ethical responsibility to disseminate decades of research findings to the general public, politicians, K-12 educators, natural resource professionals, city planners, and the next generation of scientists. Scientists have reached clear consensus about the problems posed by Eastern redcedar invasions. The ERCSLP provides the facts that should be used to question existing land management practices, to critique existing government policies and future proposals, and to hopefully create a more literate and informed society. My goal is that every citizen in the Great Plains knows the costs of Eastern redcedar invasion and the underlying reasons for why scientists continue to draw attention to this environmental problem.

How did we get here? What allowed eastern redcedar and other conifer trees to expand their ranges so dramatically? 

These are two of the most common questions we are asked, and we actually developed a FAQ section for scientists because they were brought up so frequently (link). Eastern redcedar, while historically rare, has been part of the Great Plains ecosystem for millennia, but it is one of the most fire-sensitive plants in the region. It cannot resprout after a fire, so its survival strategy is to escape fire damage. Historically, fire burned so frequently, with such intensity, and across such a large part of the Great Plains each year that Eastern redcedar distribution was effectively contained in areas where fire didn’t reach.

The removal of fire’s historical control process, coupled with ubiquitous planting and distribution of Eastern redcedar, set the stage for widespread invasion and the proliferation of cedar across multiple states today.

Woody species map

This image shows the extent that woody species, led by eastern redcedars, have expanded throughout the Great Plains from 2000-2018. Image courtesy of UNL.

Why is there a such a strong sense of urgency in the Project’s language?

The strong sense of urgency in the Project’s language matches the overall narrative of scientific experts. Many people seem to expect scientists to emphasize technical points and use an almost robotic style when they communicate with the public. But there is strong concern voiced in the scientific community about the lack of attention to this environmental challenge that spans multiple states. That is what this site is all about. Increasing literacy is not just about knowing the facts, but also understanding the tone and urgency from the scientists that have spent their entire careers studying this issue.

Why tackle this problem now?

The clock is ticking to conserve the last remaining prairie regions in the central and southern Great Plains. Cedar distribution is rapidly expanding, and I am part of a group of scientists tracking its change and impact on rangeland resources. No state has effectively prevented cedar invasion from overtaking rangelands, and no state has restored large areas of rangeland after conversion occurred. The ranching community is particularly affected, since the transition from grassland to cedar woodland can displace 75% or more of rangeland productivity used for livestock production. It is simply in our best interests to tackle this problem and avoid further losses to this and other ecosystem services.

The Project’s website says that “Eastern redcedar is considered one of the greatest threats to human well-being and to the unique flora and fauna of the Great Plains.” Will you share some of the impacts to human well-being that eastern redcedars pose?

The impacts of Eastern redcedar to human well-being are very well studied. The negative consequences span wildlife and biodiversity, livestock productivity, water quality and quantity, increased wildfire danger and a reduced ability for firefighters to successfully suppress wildfires, and reductions in school funding for public education. Recent research has linked cedar impacts to today’s allergy problems and insect-based disease vectors. Very few plants affect this number and array of resources that are so important to our lives.

Are there specific types of wildlife that are more impacted by encroaching conifers than others?

Cedar so severely changes the structure and function of rangelands over time that it affects all grass-dependent species. Multiple species become rare or locally extinct after conversion to cedar woodlands. We cover this in detail in the Science Literacy webpage. However, it is true that some wildlife are more sensitive than others. For example, prairie chickens are particularly sensitive and decline at very low levels of cedar encroachment.

Aren’t there also benefits to wildlife? How do you reconcile negative consequences versus benefits?

One of the most common misconceptions is that because wildlife are seen using cedar trees, they must need them. There is a video series where scientists breakdown these types of misconceptions. Dr. Dwayne Elmore, from Oklahoma State, has a great set of points in his video and the following powerful quote, “No wildlife require cedar.” This is an important point. While wildlife might use cedar for various purposes, those uses do not outweigh the consequences to wildlife when their habitat is lost to an unsuitable, alternative ecosystem.

In short, the displacement of native species with habitat generalists that tolerate invading trees should not be acceptable to the conservation community.

Are there examples where management is sustaining rangeland in the face of cedar invasions?

Yes, there are two examples: The Flint Hills in Kansas and the Loess Canyons area in Nebraska.

In the Flint Hills, there is still a culture of fire and a relatively intact fire regime across approximately 3 million acres. It is a great example of resilient rangelands where the intact disturbance regimes build resilience, which helps prevent major problems from occurring. Fire in this region is effectively preventing the establishment and spread of Eastern redcedar.

Kansas’ Flint Hills still have an intact fire regime, which has helped prevent eastern redcedar trees from encroaching on the valuable grasslands. Photo: Jim Minnerath, USFWS via Flickr.

In the Loess Canyons area, landowners established prescribed burn associations to restore fire in an attempt to regain the livestock productivity and wildlife diversity lost to Eastern redcedar. It is one of the most heavily invaded ecoregions of Nebraska, yet landowners have been able to rebuild a fire culture and are now cooperating on over 200,000 acres. Since 2013, cedar cover has stabilized and stopped its steadily increasing trend. This is the first example we have found where a community adapted their management practices and restored fire back into the system. The result is the stabilization of a region that had become heavily infested with Eastern redcedar.

Prescribed fire in the Loess Canyons

Prescribed fire like this have helped landowners in the Loess Canyons area of NE stem the invasion of eastern redcedar trees. Photo: Dirac Twidwell, UNL

What’s next for the Eastern Redcedar Science Literacy Project?

The ERCSLP was created to meet landowner needs for communication, and we foresee it continuing to evolve in ways that meets their needs in the future. Right now, we are creating landowner stories across the Great Plains so that people better understand their legacy and management challenge.

If you could leave readers with one key take away, what would it be?

I would actually say there are two key takeaways: The first is Prevent, Prevent, Prevent. Do not underestimate how difficult it is to restore iconic rangeland regions after cedar compromises its integrity and resilience. The second is that loads of scientific evidence counters the myth that converting grassland ecosystems to forested ecosystems will actually benefit ecosystem services and human well-being.

The conversion of grassland to cedar forest does not support the same amount of diversity, agricultural productivity, water resources, or protection from wildfire risk. Sure, some species – especially generalists – use cedar trees (and other conifers), but native grassland species are reliant upon large areas of grasslands and they require those grasslands to remain healthy and tree-free. We shouldn’t jeopardize the future of those grassland-dependent species or other critical ecosystem services simply because a few localized benefits are observed when these trees invade.

Meet the Expert

Do you have redcedars in your yard?

Dirac Twidwell

Dr. Dirac Twidwell. Photo courtesy of UNL.

My family and I just bought a property, and it happens to have lots of Eastern redcedar. I look forward to teaching my kids proper rangeland management, so I would enjoy answering this question again in a couple of years.

What is your role with Working Lands for Wildlife?

I am a science partner with Working Lands for Wildlife and share the philosophy of scaling up conservation for future generations to enjoy productive and diverse ecosystems. My aim is to co-produce science that can help the team address some of the grand challenges we face in rangelands and to better unify expertise across private-public-academic partners, especially in the Great Plains. More importantly, being involved in Working Lands for Wildlife helps me better understand how to develop use-inspired science.

What do you like to do in your free time?

Family, fishing, and travel. I also better mention that I am a lifelong St. Louis Blues Hockey fan since they won their first Stanley Cup this year!