Plant a Prairie February 13!

This post was written by Evan Barrientos, one of our Hubbard Fellows.

Have you ever explored a restored prairie and stopped to marvel at how the site was once a cropfield? Do you ever wonder how that transformation happens? Would you like to do it yourself? If so, then do I have an opportunity for you. On Saturday, February 13, 9:00am  you are invited to help seed our newest prairie and wetland restoration at the Platte River Prairies! A potluck celebration will be held afterwards!

It amazes me that prairies like this were cropfields just two decades ago.
It amazes me that prairies like this were crop fields just two decades ago. On Feb 13 you can help plant another.

Last summer, TNC staff and volunteers collected seed from 141 species of prairie and wetland plants, mostly by hand. In August we even hired a contractor to excavate the historic sloughs found on our restoration site. Doing so will greatly add to the site’s biodiversity by creating wetland habitat. Creating diverse habitat is a key part of our restoration strategy, which is why this restoration has sandy ridges, wet sloughs, and mesic ground in between. On February 13 we will start seeding the ridges!

Dirt now, prairie and wetland later. This re-excavated slough and former weed field is ready to be seeded!
Dirt now, prairie and wetland later. This re-excavated slough and former weed field is ready for seed!

Although all steps of our restoration work are equally important, I’m especially excited about seeding this prairie. How often do you get to create habitat? Imagine bringing a grandchild to the restoration 20 years from now, bursting with flowers, birds, and insects, and telling her that you helped plant it. Maybe those prairie clovers over there even sprouted from seeds that you picked with your own hands.

If this sounds like a good use of a Saturday morning to you, please RSVP to evan.barrientos@tnc.org! Volunteers should be prepared to walk over muddy and uneven terrain for up to 2.5 hours in cold weather. Please bring water, clothes and footwear suitable for mud and cold, and a potluck dish or drink if you would like to. We will meet at TNC’s Derr House (13650 S. Platte River Dr., Wood River, NE 68883. On I-80 take exit 300; go south approx. 2 miles; turn right onto South Platte River Dr.; big red brick house on top of the hill.) We usually have volunteers come from Lincoln and Omaha; if you’d like to arrange a carpool you can do so here.

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.

Seeding With My Son

Our family owns a prairie about 15 minutes south of our house, and that ownership gives me some wonderful opportunities to share my enthusiasm about prairie ecology with my kids.  I don’t expect any of my three offspring to become prairie ecologists when they grow up, but I do hope they’ll always enjoy and appreciate prairies.  In addition, I want them to understand the importance of land stewardship and the conservation responsibility we all have – especially those of us with direct management control over land.

Daniel Helzer throwing prairie seeds at the Helzer prairie farm near Stockham, Nebraska.

Last weekend, I got to spend a couple hours with my youngest son (Daniel, age 7) overseeding of a portion of our prairie.  During the summer and fall, all three kids helped me harvest seeds from local wildflower species that are rare or missing in our prairie.  Since the end of the growing season, I’d been waiting for the right day to put together a nice family outing to throw the seeds out.  It’ll be a good bonding experience, I thought.  A great way to share in the process of restoring a piece of family land.  Something my kids can tell their grandchildren about.

So yesterday, I asked for volunteers to help me spend a beautiful afternoon at the prairie.  Not one kid wanted to go.

Fortunately, my wise (and beautiful) wife pointed out to me that asking for volunteers wasn’t always the best way to handle children.  Adjusting my tactics, I cornered Daniel and simply asked him what time he wanted to go to the prairie with me.  I then explained that we’d be working in very short grass (really tall grass can be hard on a 7-year old) and that we could quit if he got tired of it.  I also described the satisfaction he’d get next year from finding new wildflowers in the prairie and knowing that they were only there because of his work.  I’m pretty sure that’s what swayed him.  Or maybe he realized that his brother and sister were going with their friends for the afternoon and his other option was staying home with his mom – who was cleaning house.  Probably it was the satisfaction thing.

Regardless, off we went. 

The right half of this August photo is the area Dan and I seeded yesterday. A season of intensive grazing (which continued well into October) knocked back the vigor of the grasses and other plants in that part of the pasture, opening up root space below and soil and light space on the surface. The portion of prairie on the left had the same treatment the previous year, but was ungrazed and recovering this year. The majority of this prairie was converted from cropland to grasses in the 1960's by my grandpa. Some wildflower species have colonized over time, but its overall wildflower diversity is still a little low - but growing.

(I wasn’t kidding when I told Dan we were going to be working in short grass.  I’d set up the grazing on our prairie this past year such that about a fourth of the site was grazed very intensively for most of the season.  Past experience has shown me that season-long intensive grazing can lead to decent establishment of seeded plants – particularly at this prairie.  The grazing opens up bare ground for seed-soil contact, but also greatly reduces the root mass of grasses to allow new seedlings a chance to compete with those normally dominant plants.  Next year the overseeded area won’t be grazed at all, which will give the seedlings a chance to start and the existing plants a chance to recover their vigor.  I’ve never seen any long-term damage to existing plants, but this kind of grazing opens up temporary space for new recruitment.) 

When we got to the prairie, I handed Daniel a bucket of seed and explained my special technique for overseeding.  “Take this seed and throw it on the ground,” I said.  Being a very bright young man, he picked it up quickly.  Did I mention how smart he is?

We did have a brief minor issue with the wind, but that was really my fault for not including that in my explanation.  What I should have said was, “take this seed and throw it WITH THE WIND.”  After we dug a few seeds out of his eyes and he spit out the rest, things went very smoothly.

The first test throw helped us refine our methods.

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Throwing seeds with the wind is much more productive.

We spent more than an hour walking around and throwing seed on the ground (more or less strategically) – pausing now and then to look at tracks he found in the dirt.  “Those are deer tracks,” I explained.  “Yep, those too…  and those and those and those.”  Apparently, we have a lot of deer this year… 

As we worked, we also spent some time discussing the best ways Dan might try to break the ice on the pond without getting muddy.  Eventually, it dawned on me that his questions about breaking the ice were less theoretical and more like hints about what he’d actually like to be doing with the remainder of his prairie outing.  So we put the remaining seed back in the truck and headed down to the pond, where we had a great time chucking sticks and rocks onto (and occasionally through) the ice.  And, yes, he got muddy.

When we got home, I was proud to listen to Daniel explain to his mother – in great detail – the specifics of our afternoon’s conservation work.  In fact, he very precisely described both the kinds of sticks and rocks we threw at the pond and exactly how high we had to throw them so they would punch holes in the ice when they landed.  He even used the word “plummeted” appropriately.  (Did I mention he’s very bright?)  I’m sure he would have gotten around to describing the deep satisfaction he’d gained from personally participating in the restoration of prairie function and diversity, but he got challenged to a ping pong game and forgot. 

All in all, it was a pretty great day.

Why are there stripes in my prairie restoration?

The photo below was taken in September 2008.  It shows a long stripe passing through a restored prairie at the end of its 7th growing season.  The site was seeded with a drop spreader in November of 2001 (seed was broadcast on top  of soybean stubble shortly after harvest).  There are at least half a dozen of these stripes running through the prairie.  They vary slighly in width from a 1/2 meter to about 2 meters.

One of the stripes in the prairie restoration, delineated by the light colored seed heads of Canada wildrye inside the stripe and the reddish-colored big bluestem in the surrounding prairie. The site was planted in November 2001, and this photograph was taken in September 2008.

I’m confident that the stripes are a result of the way we seeded the site.  The drop spreaders we use (photo below) are named because they simply drop the seed straight out of the bottom of the spreader.  We load them up with seed and pull them behind ATVs, and try to overlap our passes slightly so we don’t create long skinny gaps that don’t get any seed.  In this case, I’m pretty sure we were a little sloppy and that these stripes are a result of not overlapping our passes very well – they line up exactly with the direction we were driving.  Because we were seeding on soybean stubble, it was hard to see the tire tracks from the previous pass, but we followed the rows as we planted so we’d at least go in a straight line.

The spreader we seeded the restoration with was similar to this one except it was a different brand and was slightly wider. There is an agitator inside and holes in the bottom, and the seed simply drops onto the ground as the spreader is pulled along.

As interesting as the visual effect is, what’s really intriguing to me is the exercise of trying to figure out why the stripes are still so obvious after 7 growing seasons (actually 9 growing seasons, because the stripes were still obvious in the fall of 2010).  We seeded this prairie with a light seeding rate (around 4lbs PLS per acre) but by its fourth growing season it was already dominated by perennial native plants.  Even if the strips we missed with the seeding didn’t get prairie seed that first year, they should have been getting seed rain from native plants (like big bluestem, which is all around them) by the 4th season.  Two or three seasons later, you’d expect that plants like big bluestem would be filling in those stripes – but it’s apparently not happening.

The stripes seem to be dominated primarily by Canada wildrye, with a smattering of other species like Canada goldenrod, annual sunflowers, and other annual weedy plants.  I’m assuming the wildrye colonized from plants that established adjacent to the stripes and subsequently dropped seed.  I can understand that.  But why didn’t other species colonize the same way?  Did the wildrye come in first and fill all of the open root spaces below ground, preventing other plants from colonizing?  Surely not.  The presence of annual plants in the stripes shows that there is space available for new colonizers.  In addition, wildrye was dominant in the rest of the prairie during the 3rd and 4th growing seasons but soon gave way to big bluestem and other longer-lived plants.  Why hasn’t that happened in the stripes?

It sure seems like there should be plenty of seed falling into the stripes from plants along the edges, but those seeds either aren’t falling, aren’t germinating, or aren’t surviving seedlinghood.  It’s like the stripes are in a sort of suspended animation – they developed into a 3rd season restored prairie and just stopped.

I’ve seen this kind of striping in some of our other prairies as well.  The most apparent is in a prairie that was seeded by Boy Scouts in 1997.  The Scouts walked back and forth across 1 acre squares we’d flagged out for them and threw seed as they walked.  That particular site apparently had a lot of Canada goldenrod in the soil when we planted prairie there because goldenrod established well across the whole prairie even though we put very little (if any) seed in our mix.  Most of that goldenrod has diminished and has given way to native grasses and other wildflowers, but there are stripes of goldenrod that have persisted – and they line up exactly with what must have been strips that the Scouts missed as they walked back and forth.  The stripes are starting to become less stark now (14 seasons after planting) but are still visible.

I’m very interested to hear from others who have seen this phenomenon.  I’d be even more interested to hear good rational explanations of why it happens.  I’m guessing it could be related to the difficulty people have experienced establishing diverse prairie restorations in old fields that have been idle for a couple of growing seasons.  I’ve always assumed that in the old field situation, a year or two of weed domination of the plant community resulted in such a high density of weed seeds in the soil that prairie plants couldn’t compete during early seedling establishment.  Maybe there’s something similar happening in the restored prairie stripes?  I’m really not sure.  I’m not worried by what’s happening (I like the heterogeneity and there aren’t any nasty weeds in the stripes).  I just don’t understand why it’s happening.

Help would be appreciated!  Thanks.