The Joy, Angst, Excitement and Dread of Walking Through a Young Restored Prairie

Anyone who has watched a prairie seeding go through its first several years of establishment will appreciate and identify with this post.  For those of you who haven’t, the best analogy I can come up with is that the experience is a little like watching your son or daughter go off into the world on their own.  You can spend tremendous energy planning ahead, preparing a site, and harvesting and planting seed, but at some point, you have to just stand back and let the new prairie stand or fall on its own.  Sure, you can jump in and knock back the weeds a little now and then, but eventual success or failure depends upon many factors beyond your control, and it can be hard to predict the result during the first few years.

In February and March of 2016, we planted about 60 acres of land with a seed mixture of around 140 prairie and wetland plant species.  The site had been cropland for many years, and then was converted to a mixture of native grasses and used as pasture.  Eventually, the site became heavily invaded with tall fescue, smooth brome, and Kentucky bluegrass.  A few years ago, we decided to kill off the existing vegetation and try to establish a much more diverse plant community.  Although it had been farmed, the site still had some remnant wetland swales that had been farmed through and partially filled, but still had some wetland hydrology.  Restoring this 60 acres feeds into our larger restoration objectives of enlarging and reconnecting remnant (unplowed) prairies in the area.

Volunteers hand broadcast wetland seed on frozen wetlands during February 2016.
This “drop spreader” was used to plant the majority of the site.

We used a combination of herbicide application and tillage to get rid of the grasses and prepare a seed bed.  In addition, (under the appropriate permits) we had a contractor with a big scraper come in and deepen/widen the degraded wetland swales.  Using seed we harvested from nearby prairies and wetlands, a couple different groups of volunteers hand-planted the wetland swales and low sandy ridges created by excavation spoil, and we used a broadcast seeder behind a UTV to plant the remainder of the site.  (Thank you to the U.S. Fish and Wildlife Service, Nebraska Natural Legacy Project, and Nebraska Environmental Trust for funding this project.)

During the 2016 growing season, I visited the site very rarely, and didn’t spend much time there when I did.  Early in the season, there wasn’t much germinating and growing except the kinds of “weeds” you’d see in an abandoned crop field (foxtails, pigweeds, ragweeds, annual sunflowers, etc.).  Later in the season, those weedy plants had grown so tall and thick, it was physically difficult to walk through them.

This photo shows the kind of weed cover that grew during the first growing season. Lots of tall ragweed and annual sunflowers were joined by some perennial sunflowers and other plant species we had seeded.  This is pretty typical of what we see during the first year of our restored prairies.

I walked around this site on Monday of this week and tried to capture what I saw with my camera.  As I explored, I experienced a roller coaster of emotions.  Some areas are looking way ahead of schedule, with a nice diversity of prairie and wetland plants coming in, while others don’t look like they’ve even started, or have problematic plants that we might eventually have to deal with.  On the whole, I feel good about the progress of the restoration, though we do have some trees to control, but my overall confidence comes mainly because I’ve been through this process many times.  We’ve had restored prairies look like junk for 4 or 5 years before finally kicking into gear, and others that look like a prairie after two years.  Very rarely have we seen plantings fail.  Regardless, it’s way too early to guess how this planting will turn out.

For what it’s worth, here is what I saw and thought about during my walk around this prairie at the beginning of its second field season.

The first thing I saw as I walked into the new prairie was a pretty good sized patch of 3-4 foot tall cottonwood trees (Populus deltoides).  The parent trees can be seen in the background.  We’ve been getting smarter about removing those kinds of seed  sources before starting projects, but these trees are growing along a public road and we didn’t have the authority to remove them.  We’ll have to evaluate our options for controlling the young cottonwoods in our new prairie.
A skeleton of an annual sunflower from the initial season shows how big some of those pioneering species were last year. Many of the sunflowers were over 12 feet tall.
Biennial wildflowers, like this prairie ragwort (Packera plattensis) germinated last year and are blooming this year. Hopefully, this one will start a colony that will help support spring-flying bees and other pollinators in future years.  A pair of crane flies are mating on top of this one.
I was excited to see quite a few sedges blooming in only their second year. We don’t always get quick establishment of sedges from seeds. This one (Carex craweii) was in a patch of maybe 10 plants along the edge of a wetland, and I found at least three other species growing elsewhere in the site.
To balance out the excitement of seeing lots of sedges, I also found quite a few areas where there wasn’t much yet growing from our seed. This big patch of marestail (Conyza canadensis) was representative of maybe 30% of the planting. I think this is a soil issue – in our alluvial soils, prairie plant communities can vary dramatically from place to place, based on the soil deposits beneath them. Restored prairies establish with great variation for the same reasons.
Canada milkvetch (Astragalus canadensis), hoary vervain (Verbena stricta), goldenrod (Solidago gigantea), and Canada wild rye (Elymus canadensis) make up a very nice patch of new prairie plants.
The wetland swales are filling in quickly with wetland plants, including lots of spikerushes, grasses, rushes, and a few forbs and sedges. Much of that vegetation came from our seed, but I think some also came from the seedbank.
We purposefully designed the wetlands to vary in their depth to groundwater so that we’d have some areas of standing water most of the time, but also many other areas that go dry each summer.
Some of the wetland pools had tadpoles in them, likely from the Woodhouse’s toads that have already colonized the area. I also saw leopard frogs hopping around.  In addition, numerous snails, and aquatic insects were moving around in the water, and dragonflies and damselflies were buzzing around above it.
This section of wetland had standing water a few weeks ago, but has now gone dry, leaving great habitat for shorebirds (but also for young cottonwoods).  The vegetation along the margin of this wetland is mostly native colonizing plant species such as fleabane (Erigeron annuus), yarrow (Achillea millefolium), and Canada wildrye.
Sweetclover (Melilotus sp) is abundant across much of the new site. Experience shows that sweet clover (though I don’t like it) doesn’t seem to actually affect plant diversity much in our restored prairies, so we’ll just let it go until the site is established well enough to support fire and cattle grazing. At that point, the cattle will keep the sweet clover suppressed because it’s one of their favorite plants to eat.
In addition to areas of strong native plant growth and others dominated still by non-native or “weedy” plants, there were also areas where bare ground was still plentiful. Again, alluvial soils make all of this really interesting because the soils vary greatly from place to place and strongly regulate plant growth.
Last year’s seed pods of Illinois bundleflower (Desmanthus illinoensis) show that this native perennial legume established and bloomed in its first year at the site.
Duck and raccoon tracks joined the tracks of many shorebirds along the edges of the restored wetlands. It’s really encouraging to see how quickly wildlife and insect species colonize these sites, even while the plant community is still young.

I’ll probably return to walk through this site numerous times this season because I can’t help myself.  Apart from working on cottonwood trees and a few musk thistles, however, it’s unlikely that we’ll actually do anything else here, so my visits will be mostly out of curiosity rather than to stimulate management.  As with this trip, I’ll see things on future walks that will encourage me and others that will make me wonder if the planting will end up as a disaster, even though I know it’s too soon to know anything.

Within the next few years, we’ll try to burn the new prairie whenever we can, and when the major grasses start to assert their dominance, we’ll begin grazing the site in ways that support a diversity of plants and animals.  Typically, that grazing begins when the site is between 5 and 8 years old.  In the meantime, there’s really nothing to do but wait.  (But I’ll still peek in now and then anyway.)

I was really glad to see coyote tracks along the edge of the site. The presence of these (relatively) large predators will be key to the long-term success of the ecological community in this restored prairie.

For those of you with technical questions about our restoration methods, we didn’t test our seed for viability, but based on previous experience, our seeding rate for this planting was probably about 2-4 lbs PLS/acre, about 2/3 of which was grasses and 1/3 was forbs, sedges, etc.  We typically broadcast our seed into recently harvested soybean fields, so this planting was a little different, but not that different.  We don’t mow weeds during the first season based on trials that have shown no difference in long-term establishment (sandy soils help keep weed densities low enough to still allow sufficient light to hit the ground, despite what it looks like in the 2016 photo in this post).  We don’t cultipack or harrow seeds in either.  We’re fortunate not to have much trouble with aggressive perennial invasive plants in our early plantings, which makes our weed control pretty easy.  Deciduous trees are the main exception to that, especially cottonwoods (as shown above) and Siberian elms (not too bad at this site).  Later, we see invasion by perennial cool-season invasive grasses, but we suppress those with fire and grazing.

How did everything work this year?

This is one of my favorite times of year.  It’s not the cool temperatures, the fall colors, or even the fall migrations of birds and insects coming through.  Instead, I like this time of year because it’s time to figure out how this year’s prairie management worked and start planning for next year.  Closing that adaptive management loop (gleaning lessons from one field season and applying them to the next) is really fulfilling for me.  I get to learn something and then put it right to use.  The only downside is waiting another year to see how things turn out again!

Northern bobwhite on fence post. Helzer family prairie near Stockham, Nebraska.
This northern bobwhite was calling from a fence post along the edge of our prairie earlier this summer.  Bobwhite are abundant in our prairie, probably because of the wide variety of habitat types available.

Earlier this week, I walked through our family prairie and tried to capture the results of 2015.  I wasn’t collecting data.  Instead, I took a few photos, wrote a few notes, and looked back at some photos and notes from earlier in the season.  I mainly tried to measure what I saw against the basic habitat objectives we have for our prairie.

Helzer Prairie Habitat Objectives

1) HABITAT HETEROGENEITY.  Provide patches of habitat that cover the spectrum from short/sparse to tall/dense vegetation, with areas of mixed-height structure in between.

2) PLANT DIVERSITY.  Increase plant diversity over time by allowing all plant species a chance to bloom and reproduce every few years, and periodically suppressing grass dominance to allow wildflowers a chance to maintain or expand their “territories”.

In general, I was pretty happy with what I saw this week.  There was definitely a wide range of habitat structure across the prairie.  We began the season by grazing most of the prairie pretty hard to knock back the vigor of smooth brome.  After that, we put the cattle into about 1/4 of the prairie for the month of June and then gradually gave them access to more of the prairie as the season progressed until they were grazing about 3/4 of the site by September.

Helzer prairie grazing. Pasture #2 se of water tank
This photo from earlier this week shows the contrast between the area in the foreground that hasn’t been grazed since May and the background where cattle have been grazing since late July.
Helzer prairie grazing. Pasture #1 nw of water tank
Some of the areas opened up to grazing late in the season weren’t grazed very hard because the grass was pretty mature by the time cattle came in.  However, the cattle did graze in patches, and also knocked down the vegetation as they walked around – altering the habitat and making it easier for both wildlife and people to walk through.

The grasses in the 1/4 of the prairie we grazed in June stayed short all season, and many of the wildflowers were also cropped off.  However, some of those wildflowers had a chance to grow back as we spread the cattle out across a larger area and they became more selective about what they ate.  Other plants went ungrazed, or only lightly grazed, all season.  As a result, the habitat structure was a mixture of short grasses and medium to tall forbs.  In July, I found a family of upland sandpipers feeding in that part of the prairie – their still-flightless chick searched for insects in the short grass while staying near the protective cover of the taller forbs.

Young upland sandpiper. Helzer family prairie. Stockham, Nebraska. USA
This young upland sandpiper and its parents were enjoying a part of the prairie where cattle had been grazing most of the season, keeping grasses short but allowing some forbs to grow tall.  The chick could feed in the open but remain close to protective cover.

Elsewhere in the prairie, the height and density of the vegetation varied by how much grazing pressure it received.  Areas that were rested much of the year were dominated by tall warm-season grasses, while areas grazed from July through September had much shorter vegetation.  Despite the fact that we’re still trying to boost plant diversity across the site (which consists of small prairie remnants surrounded by former cropland planted to grasses by my grandfather in the early 1960’s) there were good numbers of wildflowers blooming through the whole season.  In the more intensively-grazed portions, only a few species such as hoary vervain (Verbena stricta), ironweed (Vernonia baldwinii), goldenrods (Solidago sp.), native thistles (Cirsium sp.), and other species panned by cattle were flowering.  However, there were many other wildflowers blooming across the rest of the site, including purple prairie clover (Dalea purpurea), leadplant (Amorpha canescens), stiff sunflower (Helianthus pauciflorus), several milkweed species (Asclepias sp.), and many others.  The most abundant wildflowers were found in the portions of the prairie the cattle had grazed intensively in 2014 – grass vigor was still suppressed in those areas, allowing both “weedy” and “non-weedy” forbs to flourish.

Regal fritillary butterfly on milkweed at Helzer prairie, south of Aurora, Nebraska.
Regal fritillaries and other butterflies are common in our prairie. I photographed this one a few years ago as it was feeding on common milkweed in part of the prairie was only lightly grazed that year.

During 2015, just about any animal species should have been able to find what they needed in our 100 acre prairie.  Regal fritillaries had violets for their caterpillars and monarch butterflies had milkweed for theirs – and both found abundant nectar plants, including in the most intensively-grazed areas.  The varied vegetation structure supported a wide range of grassland nesting birds, including grasshopper sparrows, upland sandpipers, western meadowlarks, northern bobwhites, dickcissels, sedge wrens, and others.  Small mammal trails were abundant, as were burrows of the badgers and coyotes that hunt those mice, voles, and ground squirrels.  Best of all, there were myriad bees, grasshoppers, katydids, prairie cicadas, spiders, and countless other invertebrates doing their jobs to support and nourish the plant and wildlife communities.

I haven’t yet worked out all the details of next year’s management plans, but I know a few things.  The portions of the prairie that were grazed hardest this year will be rested for most or all of next season.  We’ll likely bump the cattle stocking rate up a little because of this year’s abundant rainfall and strong grass growth.  I’ll try to make sure cattle have early summer access to the areas where I saw lots of first-year sweet clover plants this year – grazing those areas will greatly reduce flowering and seed production.  Finally, I’m thinking about letting the cattle stomp around for a week or two in one of the wet areas they’re normally excluded from because the vegetation is getting excessively thick there.

I’ll meet with my grazing lessee (the guy who owns the cattle) in late fall or early winter.  Between now and then, I’ll likely change my mind several times about some of my plans and come up with some new ones.  Next season we’ll make adjustments on the fly as we see what happens with rainfall, grazing behavior, invasive species, and all the other factors that influence management decisions.  Then, about this time next year, I’ll be walking around the prairie, trying to interpret the results of all those ideas and adjustments.

…and I’ll be having just as much fun as I am now.