What if I told you tallgrass prairie is a human construct?
Would you think it’s less important? Less natural? Less real?
I don’t know if “human construct” is a totally fair description, but it’s certainly true that tallgrass prairie in the central United States exists because of people. In many places, it formed because of people, and throughout its range, it relies on human stewardship for its continued persistence.
Let’s step back in time a little.
While the actual timing of human arrival in North America is still being debated, there is consensus that people were here well before the ice sheets receded from the center of the continent (between 8,000 and 12,000 years ago). Those humans played pivotal roles in the ecosystems they lived in. They hunted, cultivated and transported plants, and, perhaps most influentially, actively used fire in many different ways.
As the continent warmed and bloomed after the ice age, human stewardship shaped plant and animal communities. In particular, people burned the landscape around them enough to create grasslands in what otherwise would surely have been wooded landscapes. That was particularly important in the eastern portions of the tallgrass prairie. Lightning fires were part of that story, too, but they were much less significant than the frequent, intentional use of fire by people.
In other words, if it hadn’t been for people and their stewardship of the land, tallgrass prairies would not have existed across much of what is now the Midwestern United States. Throughout subsequent millennia, people have continued their stewardship, allowing prairies to persist in places where trees would otherwise have moved in.
Chelsea Forehead ignites a prairie that will help keep woody plants from taking over this prairie landscape.
Today, the majority of tallgrass prairie has been lost, of course – mostly through conversion to row crops. The prairie that remains still relies on continuous, thoughtful stewardship by people. Without active management with prescribed fire, haying, grazing, and/or targeted invasive species suppression, tallgrass prairie transitions to something else – shrubland, woodland, or a low-diversity herbaceous community that no longer qualifies as “prairie”.
Does that reliance on people make tallgrass prairies unnatural? Does it mean we should “let nature take its course” and allow tallgrass prairie to become what it’s supposed to become?
You’re welcome to form your own opinion, of course, but I feel strongly that the answer to both questions is no. Most ecosystems on earth are strongly tied to human stewardship and have been for tens of thousands of years. It’s not that those ecosystems or the species that depend upon them would all be destroyed in the absence of people, but they’d change dramatically – and many species would suffer as a result. We humans have certainly not always done the best job at land management but that doesn’t mean we can or should abdicate our responsibility as stewards.
Speaking more locally, prairie is amazing, beautiful, and complex. The incredible, diverse ecological communities that live in tallgrass prairie rely upon our continued attention and stewardship. Losing those would be an immense tragedy.
This photo captures the essence of prairie. The more you look, the more you see.
Tallgrass prairie isn’t less important, natural, or real because it relies upon humans. Instead, our long-standing, interconnected, and interdependent relationship with the prairie should increase its relevance and value to us.
Just as with any other worthwhile relationship, though, we can’t just ignore the prairie and hope for the best. Only thoughtful, adaptable care will ensure we can keep this good thing going for a very long time.
Additional Reading. If you want to learn more about the long relationship between humans and nature (prairies and otherwise), here are a few recent journal articles you might enjoy. They’ll get you started and provide many other references you can dig into if you want to keep going:
Almost a decade ago, I wrote about two competing metaphors for prairie restoration. I suggested we view prairie restoration like the reconstruction of a city after a disaster rather than like the restoration of an historic building. We need to concentrate on the roles and functions of prairie ecosystems rather than how closely a restored patch of prairie resembled what it used to be in the past.
Today, I’m hoping to stimulate conversation about the difficult decisions we face as we try to conserve prairies in the face of rapid climate change. One conservation planning approach is to focus on conserving the stage, not the actors. It advocates prioritization of sites with geophysical diversity because those abiotic conditions influence habitat heterogeneity, which supports biodiversity. The hope is that we might be able to conserve “an abiotically diverse ‘stage’ upon which evolution will play out and support many actors (biodiversity).”
The varied topography and the habitat size and connectivity found in Flint Hills of Kansas makes it a ‘stage’ that can potentially sustain biodiversity – but only with thoughtful, persistent, and adaptive management.
I think the ‘conserve the stage’ approach has merit, but it’s just a first step, especially for prairie conservation. We don’t just want to save the stage; we want to make sure the show goes on. Thus, I present to you a long (and potentially ridiculous) metaphor for prairie conservation that builds upon the ‘conserve the stage’ approach.
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Every actor in a theatrical production plays a role that helps tell a story. Likewise, every species in a prairie plays a role that contributes to the overall functioning of the ecosystem. In a healthy and resilient prairie, all the key roles in are filled.
Fortunately, there is a lot of redundancy built into prairie communities. We have lots of species that provide pollination, seed dispersal, nutrient cycling, and all the other essential functions that keep prairies going. We have a big cast, or maybe a big actors’ union.
Today’s prairie ‘show’ already looks different than it did in the past. Prairie landscapes are fragmented, invasive species have joined the cast, and the climate is changing. Those and other factors mean that some actors who played key roles in the past are no longer part of the show, at least at some venues. Other actors remain in the cast but don’t play their roles as effectively as they used to. Despite those changes, there are still really good versions of the prairie show being presented on various stages, though the versions vary quite a bit from place to place.
To keep the show going, we, as producers and directors, have to be creative and adaptable. We face really difficult decisions, especially when it comes to actors who aren’t well suited for their roles anymore. Continuing to direct the show with those actors as the main focus can weaken the performance of others and drag the whole production down.
Making changes to the cast of a show comes with a lot of risk, however. We don’t have a lot of experience with that process and we’re likely to make mistakes. Fortunately, in most cases, there are existing cast members that have the potential to adapt their roles and take on new challenges. With some guidance, those actors will find new ways to collaborate with each other and put on a show that might not be exactly the same as we’re used to but will still have a plot we can follow and enjoy.
More frequent and severe flooding is occurring as a result of climate change. That increased flooding will likely affect which plant and animal species will persist in low-lying prairies like this one. Can we predict those changes and help guide them in ways that don’t lead to reduced biodiversity?
If more drastic actions are needed, we might recognize that some actors are on their way out and start training understudies who can gradually take over roles as needed. If necessary, we might decide to recruit actors that are playing diminished roles on other stages and bring them in to rejuvenate their careers in a more suitable situation. Similarly, we might help some of our own long-term stars find new opportunities elsewhere, rather than just watching them slowly fade away.
In some cases, the world around us might force major a rewriting of the show itself. We might find ourselves directing a shrubland or woodland production rather than a prairie show. That doesn’t mean the show will stop or become less important, but it will require a different approach, a significantly altered cast, and a lot of adaptation by all involved. However, if we stick with the mantra of ‘The Show Must Go On’, we’ll need to figure out how to adjust on the fly and sustain as much biodiversity and ecological function as we can.
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Ok, I have to break away from this tedious metaphor. The real point here is that we can’t afford to be so invested in current or past versions of our prairies that we don’t allow them to adapt to changing conditions. At the risk of sliding back into my metaphor, there are lots of old movies and plays that don’t hold up well today. Jokes that used to be funny 20 or 30 years ago aren’t funny today. Old references don’t land with new audiences. In most cases, the basic stories themselves are still solid – they just need to be adapted for today’s world. Prairies and their species also exist in a different world than they used to, and that world continues to change (very quickly) around them.
The resilience and function of prairies is highly dependent upon biodiversity, which depends upon habitat size and heterogeneity, along with other factors. Maintaining high biodiversity in prairies that exist in fragmented landscapes comes with huge challenges, which are compounded by a rapidly changing climate. Plant and animal communities aren’t the same as they were in the past and they’ll continue to change over the next few decades and beyond. In fragmented landscapes, unless we take an active role, those alterations will largely take place in isolation, with limited opportunities for species to travel between one prairie fragment and another. Even in landscapes with large contiguous grasslands, we’ll need to be very thoughtful about how we shepherd those prairie communities through the coming years.
These tent caterpillars probably aren’t causing serious impacts to this patch of wild plum, despite appearances. How will climate change, habitat fragmentation, and increased woody encroachment affect this insect species and its impacts on other species in the future? (This is just a random example – I’m not saying tent caterpillars are going to become a major problem!)
It’s really hard to look at the prairies we know best and imagine them with a different composition of species. We’re used to measuring stewardship success by our ability to sustain the status quo. Watching the population of a species diminish in size – or disappear entirely – feels like a major failure. Most of us have also looked skeptically at any new species that show up in a prairie, worrying about potential negative impacts of that species on the existing community.
I don’t have a lot of answers to the big questions we face. I’m certainly not ready to lay out a plan or advocate for a particular approach to managing these changing prairies. As I did in another recent post, I’m mainly trying to get some conversation going on this topic.
The best I can do right now is offer a few ideas for discussion. For example, I think we might be smart to reevaluate the way we look at our objectives for prairie management. Instead of trying to maintain the current composition of plants and animals, maybe we should focus more on biodiversity and less on which particular species are present or abundant within those communities. (That doesn’t mean we welcome invasive species, by the way. Any species – plant, animal, or otherwise – that acts to reduce biodiversity is still a problem.)
I also think we need more serious conversation about when to resist ‘state changes’ like the transition from grassland to shrubland and when to facilitate those transformations, while trying to preserve as much biodiversity and productivity as we can. Again, I have little to offer in terms of specifics, but it seems clear that we’re not going to be able to stave off those state changes forever in at least some places. Let’s start thinking about contingencies instead of just waiting for those sites to collapse.
There’s a lot of woody encroachment in this prairie. The number of trees in the surrounding landscape and a changing climate are both spurring that invasion. At what point does the fight against this kind of encroachment become fruitless? What do we do then?
Finally, it’s never been more important to find opportunities to enlarge and reconnect prairie fragments through prairie restoration. The chances are slim that a small, isolated prairie fragment is going to adapt well to a rapidly changing world. Growing the size of those fragments by restoring adjacent patches should be a top priority. Can we find new approaches for creating those restoration opportunities in strategic locations? As we do that restoration work, we should also continue to test and discuss seed sourcing strategies, including the regional admixture approach, to see if we can further bolster the adaptive capacity of those small sites.
We’ll be figuring this out as we go, and we’ll surely screw some things up, but we can’t afford to just continue reacting. At the very least, we need to be thinking ahead about the changes that are taking place and how those will affect prairies. In some cases, we should probably be ‘acting ahead’ to guide state transitions, migration of species, or simply changes in species composition within individual prairie sites.
What we can’t afford to do is live in the past. We’re hurtling into the future whether we like it or not. Let’s make sure we bring prairies along with us.
The Prairie Ecologist 