Concerns about EARTH A New Wild’s Messages About Grassland Conservation

I know that many of you watched the first two episodes of EARTH A New Wild last week on Public Television, including Episode 2: Plains.  I watched as well, and while I was glad for the attention paid to grasslands, I also had some concerns about the content of the Plains episode.  If you didn’t see it, you can watch it here.

The recent measles outbreaks in the United States have been the topic of much discussion lately.  While there is a great deal of finger pointing going on regarding vaccinations, I worry that a bigger issue is being ignored; in today’s noisy world, it is very difficult for the public to know what information is based on good science and what is not. The growth of the anti-vaccination movement is a good showcase of the issue, but the problem is much broader, spanning topics from climate change to dietary supplements.  It often seems that anyone with charisma and/or a loud voice can gain credibility and a following, especially if they are promoting a message that feeds people’s fears or tells them what they want to hear.  Cutthroat politics and a desire among media outlets for provocative stories both stoke the fire, and there is almost no way for the average citizen to sort truth from propaganda.

As a scientist who spends a lot of time and effort communicating about science, this is something I really struggle with.  I try really hard to present only the best information I can, and to distinguish between facts, assumptions, and opinions.  At the same time, I do have an agenda – I want to see prairies conserved, and I feel strongly that factors such as biodiversity, habitat heterogeneity, and ecological resilience are critically important.  While there is a lot of research that backs up those assumptions, I still have to acknowledge my biases, and I try to be careful not to pass off opinions as science.  It’s very difficult.

All of this is leads back to my main topic of this post; my disappointment in the Plains episode of EARTH A New Wild that aired on Public Television last week.  I was disappointed with the program because I thought it presented a very one-sided perspective on some ideas, and their promoter, Allan Savory, that are very complex and widely disputed. To be fair, the narrator of the series, M. Sanjayan, did mention that Savory and some of his theories are controversial, but not that numerous scientists and studies have actually contradicted those theories.  Instead, he appeared to endorse Savory’s ideas, and much of the episode explored how they could be applied in grasslands around the world.  I welcome any attention paid to prairie conservation issues, but I felt the Plains episode led people to believe that the strategies it advocated were better supported by science than they really are.

My intent with this blog post is not to discredit or disprove the theories and ideas promoted by Savory or the Plains episode.  Instead, I want to provide additional information that I hope will help round out some of the topics presented in the episode and facilitate a productive discussion among those who watched it.  The following are a few pieces of information I feel are important to be aware of as you consider the potential value and application of the ideas presented in last week’s show.

Controversy over Savory’s Big Ideas

  • Allan Savory gave a TED (Technology, Entertainment, Design) talk back in 2013 that gained a lot of attention because of its assertion that “planned grazing” was necessary to reverse desertification and climate change. In fact, he claimed that his method of intensive, concentrated grazing is the only viable solution to reverse those two processes.  The most specific rebuttal (among many) to that talk was published by five eminent grassland scientists in a Society for Range Management journal (Rangelands 35(5):72-74. 2013).  The rebuttal addresses each of the main claims made in the TED talk and refutes them.  Unfortunately, the article is not available online to those who don’t have a subscription allowing access to SRM publications.  A brief summary and links to some responses to the rebuttal are included at the end of this post if you’re interested.
  • There were many other critiques and rebuttals of Savory’s TED talk, including one by George Monbiot in The Guardian and another by James E. McWilliams in Slate.  Both echo many of the points made in the Rangelands rebuttal, and also provide links to other information, including numerous scientific studies that refute both Savory’s TED talk claims and the broader success of his Holistic Management grazing practices.  You can read a rebuttal to Monbiot on the website of the Savory Institute.
  • To be fair, it’s important to separate Savory’s “bolder” theories about desertification and climate change from his more moderate Holistic Management and planned grazing ideas, which have been incorporated by a segment of the ranching community across the world.  Among other things, Holistic Management encourages careful planning and monitoring, which is certainly positive, but its proponents also tend to promote the use of higher stocking rates than many rangeland scientists feel are sustainable.  The results of scientific studies evaluating the results of Holistic Management and planned grazing have been decidely mixed.  Some studies have supported Savory’s theories, but many others showed that planned grazing either didn’t deliver the promised benefits or performed less well than other grazing systems.   As is typical in the scientific process, more data needs to be collected and research projects need to be repeated to resolve the inconsistent findings so far.  In the meantime, however, it seems premature to conclude that Savory’s grazing strategies are obviously and significantly better than other options.
  • Allan Savory is vocal about his distaste for the use of fire for managing grasslands and excludes it from his land management recommendations. Coincidentally, there was no mention of fire in the entire Plains episode, despite it being one of the three major forces that control grassland ecosystems (along with grazing and drought).  An example of Savory’s thoughts on fire can be found in a quote from An Overview of Holistic Management and Holistic Decision Making from the Savory Institute’s website, which says that fire “pollutes the atmosphere and exposes soil contributing to desertification/climate change.”  Climate change and its contributing factors comprise a very complex web, and I sure can’t say that fire is not part of that web, but it’s also important to consider the way fire affects carbon in the atmosphere, a topic I covered in an earlier blog post.  Of course, fire can have both negative and positive consequences, as can any management tool, depending upon the way it is applied.  However, most people working in prairie conservation feel that prescribed fire is a very important tool, and there is abundant research that supports that view.  One synthesis of that research can be found here, and Chapter 4 (page 29) deals with central North America, in particular.

The Complex Issue of Prairie Dogs

  • During the segment on prairie dogs and black-footed ferrets, the Plains episode highlighted the ability of prairie dogs to increase the health of grasslands. They create habitat for other species by burrowing, and grazing/clipping of vegetation by prairie dogs can increase the forage quality of grassland areas.  All of that is true and important.  However, research also shows that prairie dogs can change the composition of a plant community in ways that lower forage quality and/or quantity available for livestock and other animals.  As a result, there is strong evidence that prairie dogs can compete with livestock for forage.
  • I was disappointed that the Plains episode focused only on the positive aspects of prairie dogs, especially because it also talked about (and showed) ranchers working to eradicate prairie dogs without really explaining why.  Balancing the ecological benefits of prairie dogs with the economic impacts they can have to ranchers is a key component of prairie conservation in North America.  It is a complex and multi-faceted issue that requires understanding and empathy on all sides if it is going to be resolved. Here are links to two recent research publications that highlight the complexities of the prairie dog issue.  The first is publicly accessible, but the second is only available to those who have journal access subscriptions.  Thank you to my friend Stephen Winter for providing these citations.

Both Savory and Sanjayan are charismatic speakers, and very effective salesmen.  The ideas presented in the Plains episode of EARTH A New Wild are attractive because they appeal to our romantic sense of balance in nature, and imply that we can play an important role in re-setting that balance.  I agree that large predators are key components of ecosystems, and that we should find ways to live with them when it’s possible, and attempt to replicate their role when it’s not.  However, I felt the Plains episode unnecessarily focused on a very narrow set of theories and proposals for grassland conservation; a set built upon widely and vigorously challenged assumptions.  I am very optimistic about our ability to conserve our grasslands and other ecosystems, but doing so will require robust and well-rounded conversations and a wide range of strategies.  As we continue those conversations, it will be imperative that we are upfront with each other about which strategic options are based on good science and which are not.

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Here are the main points from the rebuttal to Savory’s TED talk that was published in the journal Rangelands.  The rebuttal essentially focuses on Savory’s presentation piece by piece, including:

1) Pointing out the fallacy of Savory’s statements that all non-forested lands are degraded and that rangeland science fails to either understand the reasons for or to be able to mitigate that degradation;

2) Laying out the physical impossibilities of Savory’s claim that changing the way grasslands are managed could solve climate change;

3) Pointing out that photos were the primary evidence used to support Savory’s claims of restoring degraded grasslands and that several of the photos he used either had a different grazing history than Savory claimed or were from a completely different location than Savory stated.

4) Refuting Savory’s statements about the benefits of hoof action breaking up biological crusts in desert grasslands  to increase water infiltration by pointing to the well-studied ecological roles (protecting soil from wind erosion and carbon loss) played by those same crusts.

For those of you who do have access to the Rangelands journal, I hope you will read not only this rebuttal article, but also a response from Richard Teague and the subsequent response to that critique.  In addition to providing context around Savory’s climate change and desertification theories, the series of three short articles also provides an excellent synopsis of the many arguments among scientists trying to understand the complexities of grazing management.

 

 

Ruminations on Tree Planting and Prairie Conservation

Trees are great, but trees in and around prairies can negatively impact habitat quality for many grassland plant and animal species and provide points of introduction for invasive species.  Encroachment by trees has become a major threat to prairie conservation in many landscapes.  

A few months ago, I cut across the courthouse lawn on my way home from the office (I was walking – it’s a small town).  On the west side of the courthouse, there are a number of statues and other monuments memorializing veterans of various wars.  In the midst of those, however, is a very different kind of memorial (pictured below).  This plaque-on-concrete memorial got me thinking – yet again – about our relationships with trees, our desire to plant and care for them, and how that affects our former, current, and future relationship with prairie.

We love trees so much, we use them to memorialize important events and people in our lives.  Sometimes, we then create memorials to honor people who plant trees!
We love trees so much, we use them to memorialize important events and people in our lives. Sometimes, we even create memorials to honor the trees and the people who planted them!

I live in Nebraska, home of Arbor Day.  Early European settlers of Nebraska were enthusiastic tree planters for both practical and aesthetic reasons; our legislature even designated us as “The Tree Planters State” back in 1895.  There were good reason for all that tree planting.  It’s certainly nice to have shade around one’s house and yard, and a grove of trees provides a valuable shield from strong winter winds for both homes and livestock.  In addition, early settlers found the open prairie lacked adequate wood for fuel and building materials.  However, despite the numerous practical uses for trees, I think most tree planting was and is done primarily as a way to make the landscape more visually appealing.  People just like trees.

This brings me to my contemplation of tree planting and prairie conservation.  Research has shown that when given a choice, people seem most attracted to the aesthetics of a savanna-like landscape – one with scattered trees and short grass.  That mindset is evident in the way we design our yards and parks.  Not only do we enjoy having trees, we really like to plant them ourselves.  We gain immense satisfaction from the simple act of digging a hole and plopping a seed or small seedling in the ground, knowing that we and future generations will be able to watch that tree grow skyward.  The trees we plant often become almost family members in the way we celebrate their growth and mark time by how big the trees were when such and such happened.

The landscaping around the Hamilton County, Nebraska courthouse (where the above plaque is located) is a great example of the kind of scattered trees/short vegetation landscape humans find aesthetically appealing.
The landscaping around the Hamilton County, Nebraska courthouse (where the above plaque is located) is a great example of the kind of scattered trees/short vegetation landscape humans find aesthetically appealing.

This brings up two issues for those of us working to conserve prairies.  First, we’re starting from a handicapped position when we advocate for prairie conservation because prairies are not what most people visualize when they think of natural beauty.  Given the choice between a treeless grassland and a park-like landscape dotted with trees, most people would choose the wooded park as a site to photograph, hike or picnic, or build a house.  In fact, there are countless examples in which people buy a small patch of prairie for a recreational property and immediately plant numerous trees to make it “look nicer.”  We really haven’t changed much from our European settler predecessors in that regard.

Second, we haven’t yet found a prairie-related analog to tree planting; a simple activity that creates something people can take ownership of, love and nurture.  Planting trees is so easy a child can do it, and with very little investment of time or money, someone can establish a couple trees that become treasured landmarks or memorials – – which further reinforces people’s love of trees and wooded areas.  In contrast, planting prairies is fairly complicated and requires more space.  It also takes a few years for a planting to grow out of its weedy phase and start to look like a prairie.  Prairie planting can certainly be rewarding, but it’s not nearly as simple, accessible, and instantly gratifying as tree planting.

Many people find wide expanses of open prairie impressive, but not alluring.  How do we get people to care about and nurture landscapes and ecosystems they have to work to appreciate?
Many people find wide expanses of open prairie impressive but not alluring. How do we get people to care about and nurture landscapes and ecosystems they have to work to appreciate?

So how can we help people connect with prairies in the same way they connect with trees and wooded landscapes?  I don’t have all the answers, but here are a few ideas.

1) We need to encourage more people to spend time in prairies and make sure they enjoy themselves when they go. It can be a definite challenge to convince someone to take a walk in a prairie.  Even worse, when people do step foot in a prairie, many are unimpressed because they don’t really know what to look for or how to appreciate what they’re seeing.  As a result, they often walk away with an even less favorable opinion than before they came.  “It was just a lot of grass!  And I was pulling ticks off myself all night!”

A good naturalist and interpreter can lead someone on their first prairie excursion and make it a positive and thought-provoking experience.  There is no substitute for the expertise and enthusiasm of a good leader, but there aren’t enough of those people to go around.  Several Nebraska Master Naturalists approached me last year with an idea to create a “Prairie Exploration Guide” – a pamphlet/booklet designed to help newcomers to prairie see the beauty and complexity they might otherwise miss.  The guide is still in the development stage, but I have high hopes that it will be a useful tool when it’s done.

2) Using native prairie plants in landscaping is becoming increasingly popular. The public’s concern over population declines of bees and monarch butterflies is helping to spur the movement, as are issues such as water conservation.  There is no question that getting the public to buy, plant, and appreciate native prairie plants in their backyards is a major step toward building a prairie conservation constituency – and backyard prairie gardens also make real conservation contributions on their own.  Significant obstacles still hinder the movement, especially our cultural norms about what yards and gardens are “supposed” to look like, but I am optimistic about the future.

3) One successful method for engaging people in prairie conservation at our Platte River Prairies has been through seed harvesting. People identify with both the value of seeds and the idea of restoring lost habitats.  Harvesting seed is a tangible way people can contribute toward something important; they can measure that contribution by the amount of seed piling up in their buckets.  Ideally, harvesters come back and help plant the seed they picked, and then visit regularly to watch the prairie planting develop over time.

I hope that helping me harvest and plant seeds at our family prairie will help my kids develop a love for grasslands.
I hope that helping to harvest and plant seeds at our family prairie will help my kids develop a love for grasslands.

Along those lines, one of the most inspired strategies I’ve seen to engage people in prairie restoration was being done by Wayne Pauly in Dane County, Wisconsin.  I went on a tour of some of his prairie restorations back in 2004 and was very impressed with both his plantings and his involvement of volunteers. Most particularly I liked Wayne’s strategy of having volunteers “paint the prairie” with seeds during prairie plantings.  He’d give each volunteer a bucket of seeds of one prairie wildflower species and let them decide how and where to plant those seeds – allowing them to create a pattern or design of their choice (thus the idea of “painting”).  That is a brilliant idea, and one that should not only be fun on planting day, but should also draw those volunteers back in subsequent years to view the results of their work.

Humans have a long and strong relationship with trees, one that is likely embedded within our DNA.  Tree planting is an easy, accessible, and tangible way to contribute something to the natural world.  Unfortunately, tree planting doesn’t do anything to help prairies, and can sometimes be counterproductive if trees are planted in or near open grassland.  If prairie conservation is to succeed, we need to get the public excited about grasslands and combat the perception that prairies would look a lot prettier if they just had some trees growing in them.  More importantly, we need more strategies that actively connect people with prairies and give them the same sense of fulfilment they get from planting trees.  I think we’re getting better, but we have a long way to go.

Prairies Forever? Collaborative Conservation for Pheasants, Pollinators, and People.

Effective prairie conservation requires a collaborative effort among a wide variety of interests, including ecologists, naturalists, birdwatchers, ranchers, educators, hunters, and others.  Each of these might approach prairie conservation from a different perspective, but they have more in common than you might expect. 

People outside Nebraska might be surprised to learn that one of the strongest forces for prairie conservation in our state is Pheasants Forever.  Pheasants Forever, along with its sister organization Quail Forever, is helping protect, restore, and manage prairies in multiple ways, including:

–          Private lands biologists (17) who work with landowners on habitat projects, providing both advice and access to federal, state, and private cost-share assistance.

–          Promoting and facilitating the use of prescribed fire across the state by providing equipment and training opportunities, helping to establish and coordinate prescribed fire associations, and organizing landowner tours to showcase the value of prescribed fire.

–          Promoting the use of, and helping to provide, diverse native seed mixtures for habitat restoration/improvement projects.

–          Organizing workshops and field tours on habitat management, prairie restoration, plant identification, and pollinator conservation.

Pheasant hunters
These pheasant hunters enjoyed a very successful day in a recently-restored high-diversity prairie.  The Nature Conservancy’s Platte River Prairies, Nebraska.

The man who has provided most of the energy for these efforts for more than 20 years is Pete Berthelsen, who has just stepped into a new role for Pheasants Forever, Inc. and Quail Forever; the Director of Habitat Partnerships.  He is now charged with taking the kinds of habitat partnerships and statewide habitat programs he helped develop in Nebraska and replicating those programs across the organization at the national level.

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The Right Metaphor for Prairie Restoration

Prairie restoration can be a powerful tool for grassland conservation, but we’re not taking advantage of its full potential.  Too often, we think and talk about prairie restoration (aka prairie reconstruction) in the wrong way.  Instead of trying to restore an ecosystem, we try to reproduce history.

Nelson Winkel, land manager for The Nature Conservancy’s Platte River Prairies, harvests grass seed using a pull-behind seed stripper.

I was in Washington D.C. a couple weeks ago and visited Ford’s theater, where President Lincoln was assassinated in 1865.  After the death of the president, the building went through drastic changes, including being completely gutted after a partial collapse of the interior.  By the time the decision was made to restore the building for use as a historic site, the National Park Service basically had to start from scratch.  Regardless, through painstaking research and a lot of hard work, the theater was rebuilt to closely resemble Ford’s theater of 1865.

The rebuilding of Ford’s theater is a decent metaphor for much of the early prairie restoration (or reconstruction) work dating back to the 1930’s in North America – as well for some of the restoration work that continues today.   In the case of prairie restoration, someone identifies a tract of land that used to be prairie but has been converted into something completely different (usually cropland), and tries their best to restore what was there before it was converted.  Just as in the restoration of Ford’s theater, the prairie restoration process requires lot of research and hard work to identify, find, and reassemble what had been there before.

Unfortunately, the Ford’s theater approach has turned out to be a poor fit for prairie restoration.  Prairies aren’t buildings that have specific architectural plans and well-defined pieces that can be collected and assembled to create a pre-defined end product.  Prairies are dynamic ecosystems that are constantly changing and evolving, and their components include organisms that interact with each other in complex ways.  Trying to recreate a prairie that looks and functions just as it used to – especially on a small isolated tract of land – is nearly impossible.

Reseeded prairie at The Nature Conservancy’s Kankakee Sands Restoration Project in Indiana. If the plant community today looks different than it did before it was farmed, is that really a failure of the restoration project?

That doesn’t mean small scale prairie restoration is a bad idea.  I think reestablishing vegetation that is similar to what was at a site many years ago can have tremendous historic and educational value, and can also provide important habitat for many grassland species.  Where this kind of prairie restoration falls flat is when we expect too much from it.  It’s really easy to find glaring differences between the restored prairie and what we know or think used to be there – soil characteristics are different, insect and wildlife species are missing, plant species are too common or too rare, etc.  These “failures” have led some people in conservation and academia to become disillusioned with the whole concept of prairie restoration.

In reality, prairie restoration has proven to be very successful, and is a tremendous tool for grassland conservation.  We just need to find and apply a better metaphor.

A Better Metaphor for Ecological Restoration

Unlike efforts to restore old buildings, prairie restoration projects should not be aimed at recreating something exactly as it existed long ago.  Instead, effective prairie restoration should be like rebuilding a city after large portions of it are destroyed in a major disaster.  When reconstructing a metropolitan area, replicating individual structures is much less important than restoring the processes the inhabitants of the city rely on.  The people living and working in a city depend upon the restoration of power, transportation, communication, and other similar functions.  Those people don’t care whether roads, power lines, or communication towers are put back exactly as they were before – they just want to be able to get the supplies and information they need, and to travel around so they can to do their jobs and survive.  Restoration success is not measured by how much the rebuilt areas resemble the preexisting areas, but by whether or not the city and its citizens can survive and thrive again.

Similarly, restoration of fragmented prairie landscapes should not be an attempt to recreate history.  It should be an attempt to rebuild the viability of the species – and, more importantly, the processes – that make the prairie ecosystem function and thrive.  Success shouldn’t be measured at the scale of individual restoration projects, but at the scale of the resultant complex of remnant and restored prairies.  Are habitat patches sufficiently large that area-sensitive birds can nest successfully?  Are insects and animals able to travel through that prairie complex to forage, mate, and disperse?  Are ecological processes like seed dispersal and pollination occurring between the various patches of habitat?  When a species’ population is wiped out in one part of the prairie because of a fire, disease, or other factor, is it able to recolonize from nearby areas?

Pollination is an example of an important process that drives prairie function. Increasing the size and/or connectivity of prairies by restoring areas around and between prairie fragments can enhance the viability of pollination and other processes.

At first glance, choosing the appropriate metaphor for prairie restoration may seem insignificant compared to other challenges we face in grassland conservation.  However, if we’re going to successfully restore the viability of fragmented prairies, we can’t afford to waste time and effort worrying about whether or not we’ve matched pre-European settlement condition, or any other historical benchmark.  Instead, we need to focus on patching the essential systems back together.

After all, we’re not building for the past, we’re building for the future.

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Read more on this subject…

– An earlier blog post about using prairie restoration as a landscape scale conservation tool.

– A prairie restoration project case study, with ideas about how to measure its success.

– Some recent early attempts we’ve made to measure restoration success by looking at the responses of bees and ants.

– A post about the importance and definition of ecological resilience in prairies.

How Should We Manage Small Prairies?

Prairie management can be complicated, regardless of how big a prairie is.  Managing small prairies, however, is especially challenging, and it can be difficult to know how to set appropriate objectives – let alone how to achieve them.  Living in east-central Nebraska, I’m in the transition zone between the small fragmented grasslands of the tallgrass prairie to the east and large expansive prairies to the west of me.  Because of that, I have done a lot of thinking about what objectives and strategies might apply to small prairies, large prairies, or both.  I certainly don’t have all the answers, but I thought I’d lay out some thoughts and get some input from those of you reading this blog.

When thinking about small prairie conservation there is good news and bad news.  I always like to start with the bad news…

BAD NEWS

Size Restrictions

There are some prairie species that simply can’t survive in small prairies.  The prairie size limitations of birds, for example, have been well studied.  Very few bird species will attempt to nest in a five or ten acre prairie, and the few that do will likely face high predation rates.  Red-winged blackbirds and dickcissels are examples of birds that often will nest in small prairies, while upland sandpipers, bobolinks, and Henslow’s sparrows typically choose much larger prairies – perhaps 100 acres or bigger.  Greater prairie chickens need large prairies too, but chickens also need the surrounding landscape to help provide the full suite of their habitat requirements (courtship display sites, nesting areas, brood-rearing habitat, and winter cover).

The bison is another example of a prairie species not often found in small prairies.  Since bison are also livestock (outside of a few very large public refuges in the west) their need for large prairies is due to a combination of the life history requirements and the logistics of handling and caring for them.  The necessity of strong fences, watering facilities, robust catch pens and corrals for annual inoculations, and other infrastructure associated with appropriately handling bison as livestock makes the species expensive to own and manage – especially on small sites.  More importantly, bison are just made for large spaces.  Their social structures, feeding behavior, seasonal movement patterns, and other characteristics are best suited for very large grassland areas.  Because of all these factors, the bison managers I know and respect typically recommend prairie sizes of several thousand acres as a bare minimum for the species.

Bison fit best in prairies that are thousands of acres in size.

Population Viability

Small prairies mean small population sizes for the species living in them.  You can only fit so many individuals of a species into a tiny area of habitat.  This creates problems because small populations are much more vulnerable to local extinction (disappearing from a particular place) than larger populations.  For example, a deadly pathogen such as a fungal or bacterial infection that might affect only a small portion of a species’ population in a large grassland could easily wipe out the entire population of that species in a smaller prairie.  Similarly, it’s rare that a single fire consumes all of the vegetation in a large prairie, so unburned refuges are left for insects and other animals that are particularly prone to being killed by fire.  However, a prescribed fire or wildfire that burns an entire small prairie could easily kill every single individual of a sensitive insect species.  This kind of vulnerability means that populations of rare or sensitive species are really just hanging on by their fingertips in many small prairies, and a single event could completely eliminate them.

Isolation

Often, small prairies are geographically separated from other prairies.  That kind of isolation means that if one of the events mentioned above happens to knock a species out of a small prairie, there is little to no chance of the species recolonizing from another similar site.  In addition, a small population in an isolated prairie is not interacting genetically with other populations, and that can lead to degradation of the genetic health of a species.  Poor genetic health increases a species’ vulnerability to diseases and reduces its ability to adapt to changing conditions.

The conditions that create isolation differ by species.  Birds, for example, are much more able to move from one prairie to another – even across relatively great distances – than a walking stick insect.  Because of that, two prairies could both be easily accessible to a bird, but to a stick insect those prairies might as well be on different planets.  In addition, the land cover between prairies affects species differently.  A mouse might not have any trouble moving across a gravel road, but Ron Panzer’s research near Chicago (and that of others) has shown that some leafhoppers and other insect species see those kinds of roads as impenetrable barriers.

Management Challenges

In addition to biological issues, small prairies can also present many logistical challenges to managers.  For example, grazing is usually not feasible at small sites because the cost of necessary infrastructure is prohibitive.  Small prairies can also be difficult to break into multiple management units so that one portion can be hayed or burned while another is idled.  In some cases, small prairies that are near urban or suburban areas – or other areas sensitive to smoke – can’t be managed with prescribed fire because of local regulations or because it’s not possible to prevent smoke impacts to neighboring areas.  All of these factors reduce the number of options available to a prairie manager already struggling with the biological challenges listed above.

Prescribed fire is an important tool for prairie management, but can be difficult to use in some small prairies.

As a final insult, small prairies are also much more vulnerable to outside threats such as invasive plant species, as well as domestic cats and other predators.  In a large prairie, Siberian elms invading from a nearby woodlot might affect one corner of the prairie, giving a manager time to recognize the threat and suppress it before it spreads across the entire site.  Smaller prairies can often be completely overrun by an invasive species before the manager even recognizes its existence. In addition, raccoons, cats, and other predators can range easily across a small prairie and greatly reduce the possibility of survival for many bird, mammal, or reptile species.  Large prairies contain interior areas that are far enough away from wooded edges and neighboring farmsteads to escape those “edge habitat” predators.

Uncertainty

Unfortunately, our state of knowledge about small prairies, habitat fragmentation and isolation, and the ways in which those conditions affect prairie species is pretty limited.  Which species are most vulnerable to small prairie size?  What counts as a prairie to various species?  Is a Conservation Reserve Program (CRP) grassland planting with warm-season grasses and a few wildflower species sufficient to maintain bird populations?  What about bees or other species?  Can those low-diversity habitats facilitate travel between otherwise isolated prairies?  If so, for what species?  How well do prairie habitats along road ditches act as corridors between prairies?

What kind of plant diversity and/or landscape configuration is necessary to support populations of bees?

In many ways, we’re flying blind.  It’s easy to say “the bigger the better” but that doesn’t do much to help managers who are trying to conserve what they can in prairies that are small and likely to stay that way.  There is research underway – including some that I’m involved with – that will help us better understand the impacts of habitat fragmentation and small prairie size on grassland communities, but we’re a long way from understanding some very important fundamentals.

GOOD NEWS

Fortunately, though the prognosis for small prairies can appear bleak, there is also much reason to hope.  There are numerous examples of very small prairies that have maintained populations of hundreds of plant and insect species through more than a century of isolation from other prairie habitats.  Yes, there are some rare butterfly species and other insects that are often missing from tiny grasslands, but most other species have managed to hang on.  In addition, while it’s no longer possible to support wide-ranging species such as prairie chickens or bison in small prairies, the absence of those species doesn’t impact the chances of survival for the vast majority of others.  Sure, it’d be nice to have those large charismatic species, but missing them is more of an emotional issue than a functional one.

Life in small prairies is not getting any easier, and many of the species that have survived to date are likely to face increasingly greater challenges.  In addition to the plight of individual species, ecological processes such as pollination and seed dispersal that help hold prairie communities together are much more fragile in small sites.  However, I think we can take great hope from the resilience that prairies have shown so far, and use that hope to fuel us as we forge ahead.

DECISIONS

So what’s the right way to look at small prairie management?  Perhaps the most difficult (and most important) task is to set appropriate objectives.  Let’s assume for the moment that we’re trying to select management objectives for a 10 acre isolated prairie.  I think it’s safe to say that we can exclude prairie chickens and bison from the list of species to aim for, but what about a rare insect?  Let’s say there’s a rare butterfly species that lives in that prairie, and that the larvae overwinter in the litter from previous years’ vegetative growth.  Spring fires are probably deadly to those overwintering larvae, and one fire that spreads across the entire prairie would probably wipe out the species from that site for good.  This brings up some hard choices for a manager.  Is prescribed fire off the table as a management tool?  If so, what are the ramifications for the rest of the prairie community?  What if there was a rare plant species in the same prairie that relied on periodic spring fires?  What if the absence of fire led to rapid expansion of woody vegetation or an invasive grass species, thus changing the plant community in ways that decreased overall plant diversity – thus decreasing habitat quality for the rare butterfly?  (eek!)

It would be hard to fault the prairie manager for deciding that the rare butterfly should be the top priority for management objectives.  On the other hand, a strong argument could be made that the long term survival of that butterfly is unlikely, regardless of the manager’s best efforts.  A single wildfire, a late freeze or cool/wet spring, a disease outbreak, or innumerable other events could spell the end of that tiny vulnerable population.  Is it worth putting other species at risk or decreasing the overall ecological resilience of the prairie in the faint hope of preserving one species for a while longer?  Maybe.  I don’t think there’s a right or wrong answer – just tough choices.

If the rare butterfly was a rare plant species instead, the choices would still be difficult.  Should the manager attempt to maximize the survival of the individual plants within that species even if that management decreased the survival chances for other prairie species?  If a more balanced approach was desired, would it be ok to implement a management regime that prevented those rare plants from blooming in some years, or even decreased the population size?  If that management strengthened the surrounding prairie community, making it more resistant to invasive species or supportive of a stronger pollinator community, would that offset the decrease in population size for the rare plant?  Maybe.  Again – tough choices.

What if a prairie manager decided that the best and highest use of a 10 acre isolated prairie was for education?  Would it be ethically wrong for that manager to burn the entire prairie each spring to maximize showy wildflowers as a way to draw people to the prairie?  If that wildflower display led the prairie to be used by classroom teachers, and hundreds of kids a year had a chance to explore the prairie, would that be worth the potential sacrifice of a rare butterfly species and/or a rare plant species at that particular site?  If that application of fire eventually led to the loss of other plant and animal species not favored by annual burning, would the ensuing loss of ecological resilience and the potential risks associated with that be worth the educational value gained?  Maybe.  That’s a lot of school kids.

Capturing the attention of the public might be the highest and best use of some small prairies - even if that comes at the expense of other conservation values such as plant diversity or rare insects.

Narrow or Broad?

In some ways, the management choice comes down to a choice between narrow and broad.  Should the manager restrict management in ways that favor a particular species or a particular “look” or should the manager attempt to manage for a broad suite of species at the potential expense of a few rare ones?  If the former choice is made, there are certainly risks associated (see my earlier post on Calendar Prairies).  However, if the latter choice is made, the risks may be equally high.

In my opinion, the broad option – managing a prairie for biological diversity and ecological resilience -means that each portion of the prairie needs to be exposed to a shifting mosaic of disturbances over time.  Theoretically this kind of management gives every species in the prairie an opportunity to thrive.  In our example of the 10 acre isolated prairie, this might mean that several different management activities occur each year.  For example, in one year, a third of the site might be hayed in the summer, a third might be burned in the early spring, and a third might be left idle.  In the next year, ½ of the site might be burned in the late spring and the other half might be idled – and so on.  Over time, a plant growing in any particular location should get the periodic opportunity to bloom and reproduce in conditions that favor it. Relatively mobile animal species should be able to locate suitable habitat in most or all years.  Less mobile animals might have to suffer through a tough year now and then in return for banner years in between.  Of course, all of this is much easier to accomplish on larger sites than on smaller ones, and the margin of error – and the penalties for those errors – would be less of a concern if the prairie was 300 acres in size instead of ten.

Is this really the best approach for small prairies?  While this kind of dynamic management could help support a wide diversity of species, it might also have the opposite effect.  With narrowly-focused management, selected species are continually favored over others, and those less fortunate species will probably fade from the community over time.  However, with dynamic management, EVERY species has to survive periods of management that make life hard.  When dealing with small populations, every hardship a species has to endure could potentially be its last.  Does adversity make those species tougher, or does it slowly weaken them until they die?

As a final consideration, most small prairies have long histories of fairly repetitive management (annual haying, regular burning, etc.) and it’s not always easy to predict what positive or negative impacts might result from changing that management to something more erratic.  It’s possible that altering the management regime that has allowed the current suite of species to survive so far would shake things up in a way that makes the situation worse, not better.

Taking into account the potential benefits and risks from broadly-focused management, is it really smart for a manager to choose the dynamic management approach?  Is the risk of losing rare species or the uncertainty about the results of shaking up a long history of consistent management worth it?  Again – maybe.

CONCLUSION

There are no easy answers when it comes to the management of small prairies.  Poor population viability, increased risks from invasive species and other threats, and inherent management complications can make a manager’s job seem almost impossible.  On the other hand, it’s important to remember how many species have survived thus far – largely on their own.

Prairie coneflower (Ratibida columnifera) is a tough species that has been able to thrive in prairies that have been highly fragmented and/or otherwise degraded. Many other species have also found ways to survive too - and likely will for the foreseeable future.

The biggest challenge for a manager is to identify appropriate objectives.  It can be easy to try to make a small prairie be more than it can be.  Wide-ranging species and rare species that have narrow habitat requirements can both be very difficult to maintain.  While there is no right or wrong way to set objectives, choosing to manage for those species is likely to lead to frustration and failure unless the surrounding landscape is very supportive.  Managing too much for a few species may also lead to the loss of other species and a degradation of the ecological web that supports the very species being targeted for management.  On the other hand, particularly in the case of rare species, it may be that prolonging the survival of small populations can give larger region-wide recovery efforts needed time to be successful.  Again, there are no easy answers.

In most situations, I think it probably makes the most sense to manage small prairies with the objective of maintaining the highest possible number of species (and hopefully, ecological processes) – even if this might result in the loss of some of the less common or adaptable species over time.  Because species diversity is strongly tied to ecological resilience, and small prairies are already more vulnerable to many threats than larger prairies, it seems logical that sustaining diversity and resilience should be paramount.  When doing this, it’s important to provide dynamic and non-repetitive management treatments, but also to recognize and respond to the high risk posed by invasive species and predation coming from the borders of.  Vigilantly patrolling for invasive plants and minimizing habitat that encourages predators such as raccoons and cats are examples of strategies that can help.

Even if a prairie manager does everything right – whatever that means – small prairies are destined to lose species over time.  Weather events, diseases, wildfires, population cycles, and other occurrences are outside a manager’s control but inevitable.  It’s probably smart for managers to resign themselves to that inevitability and focus on what they can control.

Ending with Hope

While it can be depressing to think about the long-term future of small prairies, there are two big rays of hope worth remembering.  First, as mentioned earlier, some small prairies lend themselves very well to providing educational opportunities for the public.  If those prairies can be used to raise awareness and help build a stronger constituency for prairie conservation, that’s an awfully big contribution to the world.  Second, in an earlier post, I described the ways that prairie restoration (aka reconstruction) can and is being used to enlarge and reconnect small prairies.  It’s expensive, and not feasible in all situations, but we have the technology and expertise to do it.  That means we don’t  have to just sit and watch the long-term degradation of tiny remnant grasslands and the populations of species they support.  Our growing ability to stitch the prairie landscape back together might be our greatest hope of all.

Why Are We Spending So Much Time Studying Birds?

Believe it or not, I really do like birds.

(And thus starts another blog post destined to draw the ire of my ornithologist friends…)

But here’s the thing.  I just read yet another study of grassland birds in which the researchers looked at the relative importance of variables such as habitat structure (tall, medium, and short grass, amount of shrub cover, etc.) and landscape composition (how much grassland is in the landscape).  It was a nicely designed study, but I found myself wondering how much value these kinds of studies are really adding to our ability to do effective grassland conservation.

A dickcissel sings from the top of a Woods' rose in restored Platte River prairie. Compared to most other kinds of animals and plants, we have a pretty solid understanding of the breeding habitat requirements of dickcissels and other grassland breeding birds.

Yes, we still have a lot to learn about grassland birds and their habitat requirements.  The more we learn, the better able to design conservation actions to help birds.  On the other hand, we already know an awful lot about grassland birds relative to other groups of grassland species like snakes, ground squirrels, grasshoppers, leafhoppers, fungi, and nematodes.

It’s kind of like we’re going to high school but only really studying in art class.  Art is important and enjoyable, but focusing only on art is not going to prepare us very well for dealing with the world.

If I was going to design a grassland landscape to maximize bird conservation, I think I could do a pretty good job based on what we know right now.  I’d start with multiple large blocks of prairie (hundreds of acres in size – much bigger, if possible).  Those blocks of prairie would need to include both upland and lowland grassland areas, and be floristically diverse enough to support an abundant supply of insects and seeds.  I’d include some scattered patches of shrubs and small trees in the landscape, but would place them so that there are still large areas of grassland with no woody vegetation at all.  Management would be important, and I would try to ensure that a variety of habitat structures was available each year, including the whole continuum between very short-cropped vegetation and tall dense and/or weedy cover.  It would be great to have those habitat types mixed together such that each block was a decent size (20 acres or more?) but that they were close enough together that birds species requiring more than one cover type during a season can easily move between them.  I’m sure those more up to speed on current literature might add a few tweaks to this landscape design, but I think this covers the more important components.

Sure, there are still a few holes in our knowledge of, especially in terms of their requirements for migratory habitat, but as a whole we’re in pretty good shape.  I would argue that our biggest limitation is not the ability to predict what birds need, but rather our ability to implement the necessary changes on the land.  However, that only applies to birds.  Does anyone feel they could similarly and accurately predict the landscape scale habitat needs of the smooth green snake, Franklin’s ground squirrel, or the long-jawed orbweaver spider? Not me.

A smooth green snake found in the Platte River Prairies, Nebraska. Very little is known about the habitat and/or landscape requirements of species like this one. We don't even really know much about how many there are. They are considered to be rare in most places, but we find them fairly regularly in our prairies - they're just really hard to see!

It would be different if we were confident that a landscape designed for birds would provide for the needs of all other prairie species.  I think we’re far from being able to say that.  Here’s just one reason I’m skeptical:  Grassland bird species are extremely mobile, and most migrate long distances between breeding seasons.  This allows those birds to find the best appropriate habitat (within reason) each year, even if that habitat isn’t where it was the previous breeding season.  Most other grassland species don’t have that kind of mobility, but many (most?) of them have fairly specific habitat structure requirements.  When the habitat structure where those species are living changes, how far can they travel to find appropriate habitat?  What kinds of terrain can they cross?  These are questions with huge implications for how we should be managing prairies and prairie landscapes, but we can’t do anything but make wild guesses because although we know how birds deal with those issues, we don’t know how most other species do.

I explored this issue of birds as indicators for the conservation needs of other species in an earlier post, if you’re interested in reading more.

Mice are fairly mobile species (compared to wingless invertebrates, for example) but we still know relatively little about their ability to find the kinds of habitat structure they need. When conditions change, do they travel long distances in search of appropriate habitat? Or do they just hunker down and wait for better times? If they travel, how far can they go, and what challenges do they face?

So why are we still spending so much time studying birds instead of branching out to other species and broader questions?  One big reason is inertia.  Scientists rightly like to build upon previous projects, so because there have already been a lot of studies of birds, there is a lot to build upon.  This makes sense in terms of efficiency (study methods are already designed and tested) and from the standpoint of funding availability (it’s often easier to sell a project that is builds upon what we already know than one that is reaching into the unknown).

A second reason we study birds so much is that they’re relatively easy to see, hear, and identify.  Since most research is done by graduate students and technicians, picking species that can be learned quickly is very helpful.  I should know – I did my own graduate research on grassland birds!  However, since then, I’ve learned that it’s not that hard to pick up on the sampling and identification skills needed to study other organisms, and that with invertebrate species, there are experts that can do the identification for you.

Of course, the biggest reason we study birds so much is that we LIKE birds so much.  If ground beetle watching was as popular as bird watching, prairie research and conservation efforts might look very different!  The irony, of course, is that we’re essentially focusing a very large proportion of our research and conservation effort on only a dozen or so grassland bird species (in any particular landscape).  At least if we were studying ground beetles, we’d be looking at several times that many species – and while I don’t know that much about ground beetles, I’ll bet they would be equally good indicators of the “health” of the prairie ecosystem.

A sedge wren on velvety gaura in the Platte River Prairies. Tiny birds, with cute little tails and aggressive personalities, sedge wrens are great examples of why birds are so compelling to people.

Look, I get it.  We’re not going to turn this battleship on a dime and move all the bird research funding and effort into smooth green snake and ground beetle research within a year or two.  However, I do think it would be really valuable for those doing bird research to incorporate broader community questions into their projects, whenever possible.  Maybe we could start by asking questions about how well birds really do represent the needs of other species?  Would funders of grassland bird research be open to that line of exploration?  It would allow us to build upon what we know about grassland birds by testing those known parameters on other taxa.  If we could figure out where the needs of birds and other species diverge, that’d be a great step forward in terms of defining future research needs.  Are great prairie chicken landscapes also great grasshopper landscapes, or not necessarily?  Do sedge wrens and massasaugas have similar habitat needs, or at least compatible habitat needs?  If not, how do we balance the needs of both species?  Let’s build on what we know about birds, but do it through some comparative analyses with other species.

Because you’ve got to admit – ground beetles are pretty cute too!

Ground beetles like this one (Pasimachus sp?) are abundant and diverse members of the prairie community. What do we know about their conservation needs? Not much.

Why I Care About Prairies and You Should Too

Lately, I’ve been trying to figure out why I think prairie conservation is so important.  I’m not questioning my conviction – I feel very strongly that prairies are worth my time and effort to conserve – but if I can figure out exactly what it is that makes me care so much, maybe I can be more effective at convincing others to feel the same way.

I can list off all kinds of logical and aesthetic reasons that prairies are important.  Prairies build soil, capture carbon, trap sediment, grow livestock, and support pollinators.  Depending upon our individual preferences, prairies also provide us with flowers to enjoy, birds and butterflies to watch, and/or wildlife to hunt.

The buckeye is one of the more striking-looking butterflies that can be found in prairies.

Those are all very practical reasons to think prairies are important, but I don’t care deeply about prairies because they make soil and grow pretty flowers.  More importantly, those reasons are not enough to make someone stop and reconsider a decision to plow up a prairie to plant corn or broadcast spray 2,4-D just to reduce ragweed abundance.  If prairie conservation is going to succeed, you and I both need to understand and articulate the deeper reasons that we feel prairies are worth saving.

Which brings me to Dr. Seuss.

As I was mulling over why I cared so much about prairies, the story of “Horton Hears a Who” popped into my head.  In case you’re not familiar with the story, Horton the elephant accidentally discovers an entire community (Whoville) living on a speck of dust.  After he finds and starts talking with the Whos, Horton agrees to help protect them from harm.  The other characters in the book don’t believe Horton when he tries to tell them about the Whos, and actually go out of their way to steal and destroy the speck of dust he’s trying to protect.  Only when the Whos are finally successful at making enough noise to be heard do those other characters recognize the existence of the Whos and agree to help protect them.

Dr. Seuss’s intended moral to the story (repeated many times) is “A person’s a person, no matter how small.”  It’s a fine moral, but isn’t what drew me to the story as a metaphor of prairie conservation.  Instead, I was thinking about WHY the other characters in the story finally changed their minds.   The sour kangaroo and the Wickersham brothers didn’t give up their threats to boil the speck of dust in Beezelnut oil because Horton finally came up with the right logical argument to explain why the Whos were worth saving.  They changed their minds because when they finally heard the Whos making noise they recognized and identified with the Whos as fellow living creatures.

Can you see where I’m going with this?  I think the biggest thing that drives me to devote my career (and a fair amount of my free time) to prairie conservation is that I have developed a personal connection to the species that live in grasslands.  Not only do I know those species exist, I can also identify with them and what they’re doing to survive.  By becoming familiar with them, I became fond of them.

When I was in graduate school, I studied grassland nesting birds.  I got to know those bird species well, including where they lived, how they survived there, and what motivated and threatened them.  I saw prairies through their eyes, and that made me want to help make those prairies as hospitable to birds as I could.  Eventually, I began learning about prairie plants and insects as well.  I was fascinated to find that their stories were equally or more interesting than those of birds.  Each species had their own unique set of life strategies that allowed them to survive and interact with the world around them.  As a photographer, I usually learn about new species by taking a photograph of some interesting plant or insect, and then identifying it and researching its life later.  I’ve yet to come upon a prairie species that doesn’t have an amazing life story, which means the process of discovery continues to be fulfilling for me.

Pitcher sage (Salvia azurea) is one of my favorite flowers to photograph because of it's unique color and shape. It also seems to be a favorite haunt of many insect species, judging by the number that always seem to be crawling around on or near the flowers.

As the number of species I’ve gotten to know has increased, so has my commitment to prairie conservation.  Maintaining the resilience and vigor of prairie communities has grown from something that seemed like a good idea into a personal mission.  Now I’m working to protect things I love, not just species I’d read about or knew about only in the abstract.

Be honest, would you be more likely to send money to help people recovering from a natural disaster in a neighboring town or in a town on another continent?  With rare exceptions, we’d all choose the nearby town.  Why is that?  I think it’s because we can more easily identify with the people who live there.  We can imagine ourselves in their places.  We can see the disaster and their plight through their eyes.  It’s not that we don’t care about people on other continents, but they’re naturally a little less real to us.

By the way, forming sympathetic bonds with species can be dangerous when managing prairies.  The more I know about the species living in my prairies, the more I understand the ways in which those species are affected (positively and negatively) by management activities.  Any management treatment has negative impacts on some species, and impacts from activities such as prescribed fire can be quite dramatic.  Caring about individual species to the point where I’m unwilling to do anything to hurt them would paralyze me.  Management is all about tradeoffs, and while my management objectives are to sustain all the species I can, I have to be willing to knock populations of some species down periodically so that others can flourish.  I think the key is to become attached to the species, but not the individuals.  Tricky…     

Why does all this matter?  It matters because we need to recruit as many people to the cause of prairie conservation as we can.  Excluding a tiny minority of prairie enthusiasts, when the general public thinks about nature and conservation they look right past prairies to the mountains, lakes, and forests beyond – even when prairies are in their own backyard.  After all, what’s to care about in prairies?  It’s just grass.

If we’re going to fix that, we’ll need to do more than describe how prairies can help sequester carbon, filter water run-off, or support pollinator populations.   We’ll need to introduce people to the camouflaged looper inchworm that disguises itself with pieces of the flowers it eats – and to the regal fritillary caterpillar which, after hatching from its egg in the fall, sets out on a hike that will end by either finding a violet to feed on or starving to death.  They’ll need to become acquainted with sensitive briar, the sprawling thorny plant with pink koosh ball flowers whose leaves fold up when you touch them.  And who wouldn’t love to meet the bobolink – a little bird that looks like a blackbird after a lobotomy and flies in circles sounding like R2D2 from Star Wars?

The charming and vociferous bobolink.

Through this blog, as well as through numerous presentations, articles, and tours, I spend much of my time sharing what I’ve learned about prairie species with anyone who will listen – hoping that those stories will spur people to explore prairies on their own and start to form their own individual relationships with the species and communities they find.  My photographs and narratives aren’t themselves sufficient to convert people to the cause, but maybe they can at least get some of them to put on their hiking boots and go for a walk.

What about you?  Have you met the citizens of the prairie?  If not, let me help introduce you.  If you have met them, what stories can you tell?  How will you spread your passion about prairies to others?

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Here are some accounts I’ve written about prairie species I find fascinating.  If you find them interesting too, please share these links with others!

Camouflaged Looper – An inchworm that disguises itself with bits of the flowers it eats.

Yucca Moth – A terrific relationship between a plant and the single species of moth that has the capability to pollinate it.

Submarine Sora – Ever wonder why soras and other rails are so hard to find?

Sensitive Briar – A plant with a koosh ball flower, thorny stems, and leaves that fold up.

Pussytoes – One of the first spring-blooming flowers, and a surprisingly important resource for early season pollinators.

Of Mice and Clover – A great example of the complexity of interactions in prairies.

Crab Spiders – One of the great ambush predators of the world.

Flies – An unbelievably diverse group of insects with a wide range of ecological roles.

Grasshoppers – From their cute little faces to their complex communication strategies, it’s hard to beat grasshoppers.

Are Botanists Ruining Prairies?

No, I’m not saying they do.  I’m merely conducting a thought exercise, and inviting you to come along for the ride.    …No, really – some of my best friends are botanists!  And I’m pretty sure they have a good sense of humor…

Why is it that we define prairies and prairie quality by their plant communities?  Are we making a mistake by letting botanists drive the prairie conservation bus?  Let’s review the current situation:

Today’s prairies are generally categorized as high or low quality based mainly on the composition of their plant community.  More specifically, prairies achieve high quality status by containing an abundance of “conservative” plants.  Conservative plants are essentially defined as plant species that are rare in most of today’s prairies, don’t do well in prairies that are heavily disturbed by grazing, and don’t colonize quickly into fallowed fields, etc.  Another way to think about it is that conservative plants are those deemed to be “fragile”.  Whether they really are or not is another subject for another time.

Compass plant is usually considered to be a conservative wildflower in prairies.

So, a prairie filled with lots of fragile plants is considered to be a high quality prairie.  Conversely, a prairie filled with prairie plant species that are tough and scrappy is considered to be degraded.  Come to think of it, we tend to think about human society in much the same way.  Speaking stereotypically, high society consists of fragile people with clean fingernails and uncalloused hands who have to hire low-society people to cook, clean, garden, and take care of their fancy cars.  Those low-society people work hard to feed themselves and their families, wear functional clothes (without designer labels), and often employ double negatives and words like “ain’t”.  Success in life is supposed to be measured by our ability to move from low to high, right?  I suppose it makes sense that we think of prairie conservation in the same way.

Now it’s certainly understandable that people who dedicate their lives to plants would be concerned about preserving those plant species that are the most difficult to preserve.  Conservative plants are important because they’re rare.  Most grasslands in today’s landscapes have to earn their keep, and are managed in ways that tend to favor species that are tough and scrappy, rather than those that are fragile.  In those landscapes, conservative species find hiding places on steep hillsides, in wet or sandy soils, outside fences, and in small, oddly shaped land parcels that don’t fit into agricultural systems.  The question of whether conservative plants were distributed in similar ways historically or were more widespread is a topic of much debate in prairie conservation circles.  Regardless, botanists today tend to focus their conservation energy on prairies that contain lots of fragile plants because they don’t want to see them disappear.

Botanists from the Illinois Natural History Survey look at a tallgrass prairie in southeast Nebraska as part of a research project on insects in fragmented prairies. By including a photo of them in this blog post, I am in NO way representing their opinions on conservative plants, prairie quality, or anything else. It's just a nice photo of botanists.

And conserving prairies full of conservative plants makes sense for the larger conservation effort anyway, right?  Because prairies with lots of rare plants also have lots of rare insects, rare bird species, etc.  Right?  Well – maybe not.  In fact, while there are a few instances in which that’s true (some rare butterflies, for example) there are many more cases where it’s not.  For instance, I’ve spoken with several entomologists working in eastern tallgrass prairies who have found that large and relatively “degraded” prairies tend to have much higher numbers of rare insect species than small “high quality” prairies.  In addition, two groups of Illinois entomologists have each developed their own index of prairie quality based on “conservative” insect species.  You can learn more about those indices here and here.   Both of them have found that there is often little correlation between the number of conservative insect species and the number of conservative plant species in a prairie.  In other words, even if we saved all of the remaining prairies with “high quality” plant communities, we could still lose a lot of rare insect species.

A specific insect example, and a notable exception to the aforementioned connection between rare butterflies and high quality prairies, is the regal fritillary butterfly.  States with highly fragmented grasslands, and thus a heavy emphasis on conservation of small prairies with lots of conservative plants, have very few regal fritillaries left.  In contrast, regals are among the most common butterfly species found in places like eastern Nebraska and Kansas – places full of prairies scorned by many eastern botanists as having been long-ago “ruined” by cattle grazing because they don’t have abundant conservative plant species.  Gorgone’s checkerspot is another butterfly with a relatively similar pattern of occurrence.

Gorgone's checkerspot butterfly in restored prairie in east-central Nebraska. This is a fairly common species in Nebraska, but is very rare in many eastern tallgrass prairies.

Grassland birds are rightly of great conservation concern to many people.  In fact, I think it’s a requirement that ornithologists working with grassland birds have to start every paper or presentation with the phrase, “Grassland birds are the fastest declining group of birds in North America”.  And it’s true.  So where do we find the strongest populations of grassland birds?  In landscapes full of large prairies – which typically have relatively low abundances of fragile plant species.  With a few exceptions, high quality prairies – using the botanists’ definition – tend to be small.  Again, they’re found in those hidden corners that have escaped having to work for a living.  However, grassland birds are notoriously unsuccessful when they try to nest in small prairies, and most don’t even try because the predation risk is too high, and the prairies are often surrounded by trees and/or relatively intense human activity.  Give an upland sandpiper or prairie chicken a big landscape full of nothing but cows and grass and they’re in high heaven.

Grasshopper sparrows are a species of concern, but they do very well on "degraded" grasslands with both historic and current intensive grazing. This juvenile bird is sitting on a hemp plant in a grazed prairie.

What does this all mean?  I’m not sure.  I’m certainly not saying that prairies full of conservative plants aren’t of great value.  Clearly, they contain plant species that are rare elsewhere – and some rare butterflies and other species as well.  However, it’s also clear that those prairies can’t be the sole focus of conservation if we’re going to preserve the entirety of prairie species diversity.  I also wonder whether at least some of those prairies (especially those larger than 40-50 acres or so) could play a larger role in prairie conservation if they were managed a little differently.  For example, if some of those prairies were managed for more heterogeneous vegetation structure they might become more valuable to many insect and wildlife species.   If we could improve habitat for rare wildlife and insect species while decreasing the abundance (but maintaining viable populations) of conservative plants, would that be a reasonable trade-off?

It seems to me that some of those larger prairies could accommodate some experimentation with summer fire, fire-driven grazing, and/or other less traditional management strategies by testing those strategies on a portion of each prairie.  If the results of those insects showed benefits to wildlife/insects without catastrophic impacts on conservative plant populations, it might be beneficial to periodically apply those kinds of treatments to all parts of the prairie over time.  Again, that management might reduce the overall abundance of conservative plant species somewhat – it would certainly periodically change the visual dominance of them.  Either way, the added benefits to a wider range of prairie species might be worth the trade-off.  Or, they might not.  It seems important to find out, however, since we have a lot of prairie species (other than plants) that are in need of good habitat right now.

Tallgrass prairie in southeast Nebraska. This hayed prairie has leadplant (a conservative plant species) scattered throughout, but not dense populations of it. How abundant do plant species like leadplant need to be for a prairie to be considered "high quality"?

I live in work primarily in east-central Nebraska, so the prairies I’m most familiar with are those that are dismissed by some botanists as already having been ruined by grazing.  It’s true that many of them have been severely degraded, not just by chronic overgrazing, but also by broadcast herbicide use.  However while Nebraska prairies are rarely dominated by conservative plant species, those species aren’t absent either.  Moreover, many of our restored (reconstructed) prairies have strong populations of many conservative species.  Watching those species respond to disturbances like summer fire and periodic grazing has been instructive.  Species like Canada milkvetch, compass plant, and leadplant, for example, that are often considered to be easily eliminated by cattle grazing, are thriving under a mixture of fire and grazing on our sites.  While there are still lots of questions about how/whether to use grazing on high quality prairies, we’ve certainly busted the myth that cattle automatically pick out conservative forb species for grazing (see my report on our use of lightly-stocked patch-burn grazing for details).  My hope is that the work we’re doing here can serve as a catalyst for similar experimental work in more “high quality” tallgrass prairies to the east of us.  Will those prairies benefit from shaking up their management?  I’m not sure.  Will they be ruined by the attempt?  I have a hard time believing that, but until we do some small scale experimentation we’ll never know.

These cattle are grazing selectively in the burned patch of a lightly-stocked patch-burn grazing system. (At the time of this July photo, the cattle had been in the prairie since April) Within the burned patch, some conservative forbs will be grazed - though most won't. Those grazed forbs may or may not bloom the year they're grazed, but typically do bloom the following year. Are short-term impacts on those species worth the wildlife and insect habitat benefits gained from the heterogeneous habitat structure?

Regardless of answers to the above questions, there is one thing I feel very strongly about:  Good prairie managers consider more than just their favorite plant species as they think about how to manage their prairies.  Yes, plant diversity is very important -a growing number of ecological functions and non-plant species needs are being tied to plant diversity as we continue to learn more about prairies.  But the importance of dense populations of conservative plants versus less abundant – but still viable – numbers of those species is less clear.  More importantly, we know that many species of insects (and probably other taxa) are doing better in prairies with low numbers of conservative plants.  We need to learn more about whether that’s tied to the way those prairies are managed, the landscape surrounding them, or the plant composition of those sites – or (most likely) a combination of those factors.

Are botanists ruining our prairies?  I don’t really think that’s the case, though it’s fun to poke them a little.  Most of the botanists I know are relatively well-rounded naturalists that care deeply about the conservation of prairies and other natural areas.  I do think, however, that all of us can become too attached to certain species or groups of species, to the point where it hamstrings our creativity (see my earlier post on “Calendar Prairies”).  Plants are often the easiest group to become attached to for prairie managers because they’re easy to find, relatively easy to identify (especially the big showy ones), and are comforting to see every time they bloom.  Birds and butterflies are also very popular, and easy to become attached to, but many small prairies don’t have many bird species, and butterflies are less familiar to most people than are plants.  On the other hand, beetles, leaf hoppers, flies, micro moths, ants, and the other species that actually make up the vast majority of prairies’ biological diversity are really easy for most of us to overlook.  Yet they’re really important, both for their own sake and because they play critical roles in keeping the larger prairie machine running – which supports those pretty flowers and birds.

We can all benefit from stepping outside our own comfort zone in terms of how we evaluate prairie conservation success.  As I said in a recent post, looking at my prairies through the eyes of pollinators has changed my perspective considerably over the last couple of years.  I’m working hard to learn more about other species like voles, beetles, and snakes so I can better think about their needs as well.  If nothing else, it’s fun.  But I think it’s quite a bit more important than that.

Even for botanists.

The Problem with “Calendar Prairies”

I think I first heard the term “calendar prairie” from my friend Bill Whitney of Prairie Plains Resource Institute.  He was talking about the mental image many people have of prairies that comes from seeing photographs of grasslands full of big showy flowers in books, posters, and calendars.  The term, and its implications for prairie management, has stuck with me over the years. 

 
 
 
An example of a "Calendar Prairie" photo. The Henry C. Greene Prairie at the University of Wisconsin-Madison Arboretum.

 

Unrealistic Expectations

There are a couple of dangers associated with people holding a mental image of what a prairie is supposed to look like.  The first is that it’s easy for people to have unrealistic expectations for prairies.  I’m a photographer, so I know firsthand that flowery photos don’t always represent an accurate picture of the prairie in which the photos were taken.  Photographers are often drawn to the biggest patches of showy flowers, and by creative use of perspective they can make those patches look even showier than they look in real life.  The result is usually a beautiful photograph that someone familiar with the prairie might not recognize.  To be clear, I’m not saying this kind of photography is a bad; on the contrary, attractive photographs have been extremely important for building the public’s interest in prairies. 

However, photos dominated by big showy flowers have the potential to be counterproductive as well.  For example, I worry that someone whose only vision a prairie comes from a “calendar prairie” image will be disappointed when they first see a prairie in person.  Regardless of how wonderful that real-life prairie is, it’s unlikely to live up to the photograph(s) that person has seen.  If that happens, it’s possible that a possible prairie enthusiast might instead feel duped and decide that prairies aren’t their thing after all.

For people that are already prairie enthusiasts, or perhaps prairie owners/managers, calendar prairies can become an unfair standard by which they measure the prairies they’re familiar with.  I’ve been in some astonishingly showy tallgrass prairies, where photos full of big flowers are easy to take just by pulling out a camera and shooting randomly.  However, not all prairies look like that – nor should they – and the ones that do don’t usually look like that all season long.  There are numerous conditions (including topography, soil moisture, soil texture, management history, etc.) that determine the appearance of a prairie’s plant community.  Using a calendar prairie image as the standard by which all prairies is judged is obviously naïve – much like a young woman using a movie star as the standard by which she judges her own identity.  The value of a prairie can be judged in many ways, including by its habitat value for a wide range of animal and insect species, many of which do not rely on big showy flowers.  In fact, the biggest value of an individual prairie is its very individuality – its unique combination of species composition and habitat attributes makes a unique contribution to the larger prairie conservation mission.  (Read my earlier post on this topic.)

This is not to say that all prairies are perfect the way they are.  Most (all?) prairies can be improved, but goals for improvement should be based on increasing the value of those prairies for biological diversity – not on making them look more like a photograph.

Effects on Management

The second danger of a calendar prairie image is that it can affect the way a prairie is managed.  Prairie managers sometimes form a mental picture of what they want their prairie to look like.  Sometimes that picture is based on an unrealistic idea of what prairies should look like.  Other times, it’s based on a fond memory of what their prairie looked in a previous season.  Either way, the problem occurs when that manager tries to make the prairie look like that mental picture all the time.  Rather than managing the prairie in response to threats such as invasive species, or in ways that allow different plant and animal species to gain an advantage each year, the prairie gets the exact same management treatments every year.

A summer fire on The Nature Conservancy's Platte River Prairies. We've seen very interesting and positive responses from summer fires, with and without grazing. For example, I've been managing this prairie for more than 10 years and have only seen wind flower (Anemone caroliniana) twice - both times it was growing in the portion of the prairie that had been burned the previous summer.

 

When a prairie gets the same management each year (e.g. early spring fire or summer haying) some plants, animals, and insects that are favored by that management and others are not – year after year.  Eventually, those species that are put at a disadvantage each year can disappear from the prairie.  Sometimes the strategy seems successful to the manager because the plant community appears the same each year; they always see the same big showy flowers blooming, for example.  However, other plant species may be slowly fading away.  More importantly, many animals and insects that have specific requirements for habitat structure will have a difficult time surviving in a prairie that provides only a single habitat structure type across the entire prairie each year.  Even those animals and insects that thrive may become more at risk from predation because the number of predators and their focus on particular prey species can both grow when their food source is consistently available in the same place and abundance each year.

 In a large contiguous grassland landscape, individual parcels of land that are managed the same way every year may not be a big deal – as long as there is variety among parcels.  If the Brown prairie is managed with annual late-spring fire, the adjacent Smith prairie is managed with annual summer haying, and nearby prairies are managed with other strategies, the conglomeration may retain good biological diversity, even if each individual tract of land contains a relatively narrow set of species.  However, when neighbors manage in similar ways, or when isolated prairies are managed in ways that decrease the number of resident species over time, the entire landscape can lose diversity.  If that happens, it’s unlikely that the diversity will recover because there are no places for the lost species to recolonize from.

 Ideally, every prairie would have multiple management treatments applied to various parts of it each year.  For example, a portion might be burned, a portion idled, and a portion grazed, with those treatments shifting from place to place each year – not necessarily in a predictable manner.  In a prairie managed that way, most or all plant species are likely to find favorable conditions in which to grow and bloom every few years – something that is critical to their long-term survival.  Animals and insects in a prairie that has multiple management treatments across it have a good chance to find suitable habitat each year by moving to the portion of the prairie that is most favorable in that year.

Light grazing on a restored Platte River Prairie - cattle are grazing the grass but leaving most wildflowers ungrazed. Periodic grazing can certainly change the appearance of a prairie, but plants that are grazed recover quickly. In the meantime, the grazing can provide different habitat structure and opportunities for plant species that are normally suppressed by dominant grasses.

 Some prairies are small enough that splitting them into multiple management units is not feasible.  In those cases, just shaking up the management so that it’s not exactly the same each year can be important.  Idling a different portion of the prairie each year – even if those portions are small – can provide a refuge for some of the plant and animal species that might not do well under the management applied to the majority of the prairie.  However, when prairies are both very small AND isolated from other prairies, some insect and animal species will simply be unlikely to survive long-term, even with good non-repetitive management.  In those cases, the management objectives may need to be altered – those sites could be treated more like museum pieces than prairies.

 Regardless of a prairie’s size, repetitive management over time can limit its biological diversity.  Prairies evolved under chaotic conditions; fires, grazing, outbreaks of herbivores, and drought came and went, and prairie animals and plants developed strategies to adapt.  Not only can prairie species survive management that changes year to year, they can thrive on it.

 Conclusion

Relying on idealistic visions of what prairies should look like (Calendar Prairies) creates an unrealistic image of what prairies really are.  Prairies evolved as dynamic natural communities that changed in appearance from day to day and year to year.  Rather than selling the public and ourselves on the idea that prairies should consistently look like showy flower gardens, we should celebrate and facilitate their changeable nature.  Real prairies are much more interesting (and valuable) than flower gardens anyway.

Measuring Success in Prairie Conservation – Species Composition vs. Structure and Process

Stick with me – this isn’t as complicated as the title might lead you to believe…

I was involved in an interesting discussion a couple weeks ago among some fellow prairie ecologists about what makes a “good prairie”.  The discussion brought into sharper focus something I had thought a lot about but only in general terms.  Here is the discussion – with some over-simplification of the respective positions:

Position A – Species Composition:

A high quality prairie (tallgrass prairie, in this case) can be judged largely by its plant species composition.  A “good” prairie might have 20 or 30 plant species per square meter, for example, and more than 100 species per acre – including a mixture of both common and rare species.   Besides the value for the direct conservation of species, that kind of plant diversity provides multiple ecological benefits.  More plant species means more choices for animal species that rely on them as food and/or habitat resources, as well as a more consistent supply of those resources through the season – because some plants will always be emerging/blooming as others go dormant.  Because of that, prairies with lots of plant species tend to have lots of insect and other small animal species as well.  In addition, prairies gain resilience from plant species diversity, because if multiple species fill similar ecological roles the prairie community can better withstand the temporary decline of some species due to drought or pest outbreak.   A prairie that is missing many of its species, or that is dominated by a few species with only scattered small populations of others, can’t be considered to be of high quality or to be “conserved.”

A diverse prairie at the Madison Arboretum – Madison, Wisconsin.

Position B – Structure and Process:

What really defines successful grassland conservation is the presence of large-scale and intense disturbances (e.g. fire and grazing).  The combination of fire and grazing shaped historic prairies and that combination is needed today to maintain them.  Without fire, prairies lose integrity in several ways – the most obvious being the encroachment of trees that fire otherwise suppresses.   Fire also helps drive the cycling of nutrients and regulates the amount of standing dead vegetation and thatch in prairies.  Furthermore, the high-quality of the fresh vegetative regrowth following a fire attracts intense grazing by herbivores large and small.  Historically, there would have been few cases where a prairie would burn and not be intensively grazed right afterwards.  That intense grazing suppresses dominant prairie grasses, opening up space for the abundant growth of weedy vegetation once the grazers move on.  As the prairie recovers, the dominant grasses reassert themselves and the vegetation becomes tall and dense enough to carry fire once more.  A landscape consisting of a heterogeneous mixture of recently burned patches and patches that haven’t burned for several years provides the full range of habitat structure – from very short to very tall – and thus supports the full range of prairie wildlife species.  Perhaps most valuable in that range of habitat structure is the post-fire/grazing recovery phase that provides simultaneously provides a wealth of stemmy vegetation cover and abundant seeds for wildlife food.

An expansive prairie landscape in the Nebraska sandhills.

So is Position A or Position  B correct?  Well, yes.  It’s like owning a sports car.  You need to keep all the sparkplugs, tires, and other parts – and keep them in good condition.  On the other hand, a sports car is no good if you can’t drive a standard transmission and/or don’t have good roads to drive on.  Aldo Leopold said, “To keep every cog and wheel is the first rule of intelligent tinkering” – but those important components include both species and the processes that maintain them.

Interestingly, the two positions seem to be strongly correlated with geography.  People who work with the fragmented tallgrass prairies in Midwestern States like Illinois, Wisconsin, and Indiana tend to fall more heavily in the first camp – emphasizing species composition.  In contrast, people who work in the large expanses of grassland in Oklahoma, Kansas, western Nebraska, and the Dakotas, tend to hold Position B – emphasizing process and structure.  In both cases, the positions are reasonable based on the local situation.  In the eastern tallgrass prairie, most of the prairie is gone, so any remaining grassland is precious and there is great concern about the loss of prairie plant and insect species.  Further west, where grasslands still dominate the landscape, there is much less concern about the loss of plant and insect species and more focus on larger wildlife like prairie chickens that require a range of habitat conditions not always found in those ranching-dominated landscapes.

As usually happens in a discussion among reasonable people, a partial consensus emerged in ours, and there was general agreement that neither Position A or B was sufficient by itself.  Proponents of species composition as the measure of prairie conservation success would surely not be fully satisfied with a flowery prairie that was missing species like prairie chickens, upland sandpipers, and bison.  They just don’t often have the opportunity to work with grasslands large enough to support all of those species.  Likewise, proponents of structure and process wouldn’t be happy with 20,000 acres of switchgrass just because it had a heterogeneous mix of fire and bison grazing and lots of prairie chickens.

The point here is not that we need to subscribe fully to either Position A or Position B, but that we can’t afford to ignore either one.  Those working in the fragmented eastern tallgrass prairie need to be sure to emphasize strategies like prairie restoration that can strategically convert crop fields back to prairie vegetation and enlarge remnant prairies to the point where they have a chance of supporting prairie chickens and upland sandpipers, if not bison.  And even at smaller scales, finding creative ways to reintroduce the combination of fire and grazing, where possible, may help provide better wildlife habitat – and might even pay dividends for plant species conservation (more discussion on this in posts to come.)

Meanwhile, ecologists with the luxury of large unplowed expanses of native grassland need not to forget the importance of restoring and/or maintaining both large-scale and small-scale plant diversity.  While adequate habitat structure for species like prairie chickens can be created in a landscape dominated by grasses and weedy forbs, pollinators and many other insects may have a much more difficult time surviving there.  In addition, whether the intervening landscape is dominated by grass or corn, small isolated populations of prairie forbs (and the insects that rely on them) aren’t likely to survive forever if they’re not able to cross pollinate or otherwise interact with each other.  Native bees that have to find consistent sources of nectar within a small radius from their nest rely on small-scale plant diversity to provide abundant blooms every day of the growing season – and pollination by those bees is critically important for the survival of many plant species.  Finally, proponents of process should recognize and appreciate the potential (but understudied) values associated with a diverse plant community – including a diverse and vigorous soil fauna, and the overall resilience offered by a mix of species that provides redundancy of ecological function.

The danger for all of us is that we tend to look at prairie conservation through a cultural lens – and we sometimes don’t see what our prairies, and our strategies, are missing.  It would be great if we could facilitate some cultural exchanges, in which we sent Texas cowboys to the Illinois black soil prairies and Wisconsin prairie restoration experts to the flint hills of Kansas.  Imagine the discussions that would ensue – not to mention the neighborhood coffee shop gossip.

Participants in the Grassland Restoration Network discussing prairie conservation at The Nature Conservancy’s Nachusa Grasslands, Illinois.

I feel fortunate to be involved in two groups that do a great job of stimulating interaction and discussion – the Grassland Restoration Network and the Patch-Burn Grazing Working Group.  The former is a loose affiliation of ecologists working to use prairie restoration as a tool for grassland conservation in fragmented landscapes.  The latter is a network of scientists, land managers, and ranchers trying to find better ways to combine fire and grazing and create heterogenous prairie landscapes.  (I’ll provide more information on both of those groups in future blog posts.)  Now if I can just figure out how to convince the two groups to hold a joint meeting…