The Bench Strength of Prairies in the Face of Climate Change

In case you hadn’t noticed, the climate is changing.  Things are getting weird, and they’re going to get weirder.  Here in central North America, we’re expecting more and more intense storm events and drought periods in the coming decades.  Scientists are scrambling to figure out how to predict and facilitate the inevitable changes those crazy weather events will bring to natural systems, including prairies.

Fortunately, prairies have been training for this for a very long time.  A few months ago, I wrote a post about the resilience of prairies, and how that resilience is built largely upon the diversity within their ecological communities and the size and connectivity of prairie habitats.  Prairies that are relatively big and still have the majority of their potential plant and animal species are going into this encounter with rapid climate change with what you might call solid bench strength.

Diversity of plants and animals is the keystone to ecological resilience. The Nature Conservancy’s Nachusa Grasslands, Illinois.

In sports, teams want to have lots of available players that represent a broad diversity of skills.  Each opponent they face will have its own individual mix of power, endurance, speed, and other attributes.  A successful team can build a roster for each game that counters their opponent’s strengths, no matter what they are.  The number and quality of their players is a team’s bench strength.

Healthy prairies have great bench strength too.  No matter what gets thrown at them, they can adapt by changing their roster of species.  The speed at which they can drastically change the makeup of their “team” is impressive.  Anyone who has spent many years watching the same prairie has seen this in action, but none of us have seen prairies go through what Professor John Weaver saw back in the 1930’s and 40’s.

Weaver, one of the best known prairie ecologists of all time, had been studying 30 “large typical prairies” across parts of Nebraska, Iowa, Kansas, and Colorado prior to the start of the Dust Bowl era.  His baseline data gave him an invaluable opportunity to document the dramatic changes to the plant communities of those prairies during and after the droughts of the 1930’s.  What he recorded, along with his former student F.W. Albertson, was an incredible testimony to the dynamism and resilience of those prairies.  Their 88 page 1944 publication, entitled “Nature and Degree of Recovery of Grassland from the Great Drought of 1933 to 1940”  encapsulates the bulk of their findings in one place, and is worth a read if you have the time.

In 2012, we got a small glimpse of what Weaver and Albertson saw in the 1930’s, but our drought – while severe – only lasted one year here in Nebraska.
In 2013, the response of the prairie to the 2012 drought included some explosions of wildflowers, including shell leaf penstemon (Penstemon grandiflorus).

One of the biggest plant community shifts Weaver and Albertson documented was the widespread and dramatic death of grasses such as big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparium), and Kentucky bluegrass (Poa pratensis), and the subsequent rise of other grasses such as prairie dropseed (Sporobolous heterolepis), sand dropseed (Sporobolous cryptandrous), porcupine grass (Stipa spartea), and most of all, western wheatgrass (Pascopyrum smithii).  Western wheatgrass populations exploded throughout the mid to late 1930’s, to the point where many prairies were completely dominated by it, to the near exclusion of other plant species. In fact, in a 1942 publication, Weaver said the following, “The large area of drought-damaged true prairie and native pasture now dominated by western wheat grass and the harmful effects of the successful competition for water of western wheat grass with species of greater forage value present a problem of much scientific interest and great economic importance.”

In other words, as they made massive substitutions within their lineups, prairies were changing so much they became almost unrecognizable, even to those who knew them best.  Weaver and Albertson watched waves of forb species they’d always considered to be of little value become stars on the field, and they and others didn’t quite know how to react.  Daisy fleabane (Erigeron strigosus), Missouri goldenrod (Solidago missouriensis), and heath aster (Aster ericoides) were all examples of wildflowers that suddenly rose to prominence in new and major ways.  The two dismayed scientists described how heath aster, a “nearly worthless native forb,” formed near monocultures across wide swaths of prairie, to the extent that it “ruined many of the prairies…for the production of hay, because of its brush-like growth.”  Others were out of their depths on this too, and Weaver and Albertson reported that “considerable native sod was broken because of the seriousness of this pest.”  In the following sentence, however, they begrudgingly added a short sentence, “Of course, it did protect the soil.”

While Weaver and Albertson considered heath aster to be “nearly worthless” it plays an important role in the prairie, and is an important food source for pollinators in the fall.

Exactly.  While the strategy was foreign and frightening to those who hadn’t seen prairies dealing with these kinds of conditions before, those prairies were just doing what they’ve done many times before – making whatever roster adjustments were necessary to keep functioning at a high level.  In addition to forb species they denigrated as weeds, Weaver and Albertson noted that many wildflowers with “large storage organs”, including bulbs and corms, also greatly expanded their population size during the dust bowl years.  This included species like Violet wood-sorrel (Oxalis violaceae), bracted spiderwort (Tradescantia bracteata), windflower (Anemone caroliniana), and wild garlic (Allium canadense).  Those species and others increased the size of the patches they’d occurred in previously, but also were found “in many new locations.”  Other native forbs that became superabundant in some prairies, especially early in the dust bowl years, included prairie ragwort (Senecio plattensis), white sage (Artemisia ludoviciana), and yarrow (Achillea millefolium).

Windflower (Anemone caroliniana) was one of the wildflowers with “large storage organs” that proliferated during the droughts of the 1930’s.

As rains started to return in the early 1940’s, Weaver and Albertson watched with amazement and renewed optimism as plant communities started “recovering”, which of course meant they were returning to a composition more familiar to the people observing them.  Grasses were often the first to rebound in prairies, including big bluestem, which initially formed large and lush monocultures in many places.  Wildflowers that hadn’t been seen for seven years or more, suddenly appeared everywhere, including blue-eyed grass (Sisyrinchium campestre), which grew “more thickly than if the stands of 7 normal years had been combined.”  Downy gentian (Gentiana puberula), which had been considered rare prior to the big droughts, became much more common in the early 1940’s than Weaver and Albertson had ever seen before, with abundances of “15 or more plants in a space of a few rods”.

Stiff sunflower (Helianthus pauciflorus) returned fairly quickly to “normal abundance” by 1943, as did many others, including silverleaf scurfpea (Pediomelum argophyllum), cream wild indigo (Baptisia bracteata), and buffalo pea (Astragalus crassicarpus).  Prairie violets (Viola pedatifida), pussy toes (Antennaria neglecta),  and others came back more slowly, but returned nevertheless.  Importantly, those returning species didn’t appear to be traveling from long distances.  Instead, they simply re-emerged, either from seeds or underground buds, from where they’d been sitting on the metaphorical bench, awaiting the call to step up to the plate again.

Buffalo pea (Astragalus crassicarpus) and many other wildflowers recovered from the long droughts at a speed that amazed Weaver and Albertson.

The prairies we know today have been through a lot.  In Nebraska and surrounding states, we have specific documentation of the kinds of extreme roster changes prairies can and have made to adjust to the world around them, thanks to the work of John Weaver and F.W. Albertson.  If you have a favorite local prairie, and I hope you do, it’s important to remember that the way it has looked for as long as you’ve known it is only a small sample of what it’s capable of.  Smart teams don’t reveal their secrets before they need to.

As we work to keep prairies healthy through this period of rapid climate change, it’s both useful and reassuring to remember what they’ve been through before.  Today’s prairies certainly have additional challenges to deal with today, compared to the dust bowl days (more invasive species, more landscape fragmentation, etc.), but many should still have sufficient bench strength to make the adjustments they’ll need to make in the coming years.  Our responsibility is to provide management that helps prairies sustain their plant and animal diversity, as well as to protect prairies from additional conversion to cropland or other land uses.  Where possible, restoring prairie habitat around and between prairie fragments can also help build resilience.  In short, we have to allow prairies to do what they do best – adapt and adjust.  Prairies are wily veterans and they’ve been in this game for a long time.  It’s a good bet they’ve still got a few tricks up their sleeve.

Hubbard Fellowship Blog – No “Earth” without “Art”

This post was written by Katharine Hogan, one of our Hubbard Fellows.  Katharine is multifaceted and very talented – exactly the kind of person we like having in our Fellowship program.  

I used to be a fairly prolific artist. As soon as I could hold a pencil I began drawing and copying whatever pictures of horses I could find. As a teenager, I explored multiple media and subjects, including colored pencil landscapes, watercolor and acrylic paintings, ceramic dishware, and illuminated Celtic calligraphy in inks and metallic finishes. My hands would wander over the paper, canvas, and clay for hours, creating from whatever came into my head or caught my eye. I would get frustrated, I would get inspired, and almost always something would find its way out of my head.

Around when I finished graduate school, this drive began to fade. It hasn’t disappeared – there have been occasional spurts of creation, but overall the last two and a half years have seen a huge drop in my artistic inspiration. When I did create, it was painstakingly slow and the hours no longer slipped away from me. This stressed me out. Art had been so huge in my life for so long, what was happening? Would I ever be able to access that drive again, or was it gone? Over time I became resigned, and figured all I could do was keep my mind open to any inspiration that might reemerge.

One of my few recent pieces of art, inspired by the fields of sunflowers seen along the Platte River in late summer. Photo by Katharine Hogan
One of my few recent pieces of art, inspired by the fields of sunflowers seen along the Platte River in late summer. Photo by Katharine Hogan

This past week, while I was cutting out the windows on the metal shipping containers that will eventually be The Nature Conservancy’s new sand hill crane viewing blinds, I was thinking about how even land management tasks that seem repetitive and straightforward have varying degrees of hidden skill behind their successful implementation.

The plasma cutter I was using to create the crane blind windows has a tiny spatial range where its electric arc most effectively cuts steel, and the evenness of the cut depends on holding the tip at a very consistent angle while simultaneously moving the cutter at a precise rate.

Katharine using a plasma cutter. Photo by Eric Chien.
Katharine using a plasma cutter. Photo by Eric Chien.

Safely and effectively spraying invasive plants depends on literally moment by moment interpretation of air movement, requires an understanding of how the leaves of different species shed or hold herbicide, and, of course, knowledge of sometimes subtle botanical differences between native and non-native species in various life stages.

Pausing beforehand for a sip of coffee is arguably not one of the more subtly demanding aspects of spraying weeds (in this case, reed canary grass) – but on chilly days it is one of the nicest! Photo by Katharine Hogan
Pausing beforehand for a sip of coffee is arguably not one of the more subtly demanding aspects of spraying weeds (in this case, reed canary grass) – but on chilly days it is one of the nicest! Photo by Katharine Hogan

And don’t even get me started on working with the tractor grapple. It takes less than five minutes to learn the basics of grapple operation, but it took me hours of operating those two levers until I truly began to grasp (pun intended) the subtleties of picking up and piling tree branches.

These tasks of subtle familiarity and mastery are not unlike the learning curves of artistic mediums. So, I wondered, have shop skills and land management techniques become my new artistic pursuits? Have I traded one skill for another that is often not recognized as art because it is narrowly defined with a specific, practical objective? Perhaps, but I believe it goes deeper than that.

I believe there is art hidden all around us. There is art in every efficient system of organization. An herbarium of native prairie plants is artistic in creation and appearance. Communicating with diverse audiences about the importance of prairies is an art both subtle in execution and many layered in its implications.

Our daily lives hold art as well. Aside from the more obvious sources such as cooking or interior design, there is also art in the words we give to the people in our lives, and in how we choose to spend our time so as to be more responsible with the resources in our possession. Every life can be treated like a work of art.

Art is many things. Among others, art is simultaneously the most intellectual and most visceral form of communication in its dual capacity to make us both think and feel. This communication can be purely aesthetic, or it can be pragmatic. We are all artists, whenever we take a concept to its completion in the way that best brings our talents to the rest of the world.

I still hope to rediscover my inspiration in the “traditional” studio art forms. Until then, I will simply have to do the best I can to recognize the hidden art before me every single day.

I would love to know your thoughts and responses to these ideas. Please let me know in the comments, or email me at katharine.hogan@tnc.org. Thanks! I hope you go forth and create.