A Milestone for Prairie Restoration

Because conservation work can sometimes seem like blowing into the wind, it’s important to pause periodically to celebrate progress.  For example, I am really excited about what has been accomplished in the field of prairie restoration.  We’ve known for a while that we can convert cropland to prairie vegetation with a high diversity of plant species (150 or more species per planting), and that we can do that on a scale of thousands of acres.  The Nature Conservancy has large projects in states like Indiana, Illinois, and Minnesota where restored prairie landscapes now range from about 5,000 to 20,000 acres in size.  The U.S. Forest Service is transforming an old U.S. Army Arsenal into 20,000 acres of prairie in Illinois.  Prairie Plains Resource Institute, the organization that pioneered restoration techniques in Nebraska, is planting up to 1000 acres a year now and has established well over 10,000 acres total across the state.

Our staff celebrates a successful year of seed harvest back in 2015.

Our staff celebrates a successful year of seed harvest back in 2015.

Here in our Platte River Prairies, we’ve restored more than 1,500 acres of cropland to prairie.  That’s not insignificant, but more importantly, we’ve been testing the idea that those restored prairies can help defragment the ecological landscape around them.  Habitat fragmentation is one of the largest threats to today’s prairies because it shrinks and isolates populations of species, making them vulnerable to becoming locally extinct without the chance of recolonization from nearby sites.  The real promise of prairie restoration is that it can enlarge and reconnect scattered remnants of native prairie, providing populations of animals and plants a much better opportunity to survive and thrive.  It’s not feasible or desirable to convert the majority of cropland in the central North America back to prairie, but there are particular sites where strategic restoration work could make a huge difference in the potential survival of prairie species and ecological services.

In order for prairie restoration to help defragment landscapes, restored prairies have to provide suitable habitat for the species living in small isolated prairies.  Many bees and other insects specialize on certain plant species, for example, and other animals rely upon an abundance of prey, a diversity of seeds, or other particular food or habitat conditions.  Satisfying the individual needs of all those prairie animals is a critical measure of success if prairie restoration is going to successfully stitch isolated prairies back together.

Over the last several years, we’ve been collecting data to see whether the species of bees, small mammals, grasshoppers, and ants in our unplowed prairie remnants have moved into adjacent restored habitat.  The results have been very positive.  While not every species of animal living in our remnant prairies has been found in nearby restored habitat, we’ve found the vast majority of those we’ve looked for.  We suspect that most of the remaining species are also present but that our limited sampling effort just hasn’t yet picked them up.  We’ll keep trying.

Dillon Blankenship, a Hubbard Fellow, compared grasshopper, katydid, and tree cricket communities on three pairs of remnant/restored prairies back in 2014. Almost all species were present in both restored and remnant habitats. In the three species that weren't, only one or a very few individuals were found, so it's likely just a sample size issue.

Dillon Blankenship, a Hubbard Fellow, sampled grasshopper, katydid, and tree cricket communities on three pairs of remnant/restored prairies back in 2014. Almost all species were present in both restored and remnant habitats. In the three species that weren’t, only one or a very few individuals were found, so it’s likely just a sample size issue.

Data from James Trager and Kristine Nemec has helped us compare ant species composition in restored versus restored prairies along the Platte River. So far, we've documented 30 species and only one has been found exclusively in remnant prairie (and, again, it's likely to be a sample size issue).

Data from James Trager and Kristine Nemec has helped us compare ant species composition in restored versus restored prairies along the Platte River. So far, we’ve documented 30 species and only one has been found exclusively in remnant prairie (and, again, it’s likely to be a sample size issue).

Master Naturalist Mike Schrad and Hubbard Fellow Jasmine Cutter have both helped us compare small mammal populations between restored and remnant prairies. This table shows some of Jasmine's data from one site. In general, we're finding that the same species are in both restored and remnant prairies, but the relative abundance of those species is often different - with some apparently favoring remnant habitat and others favoring restored areas.

Master Naturalist Mike Schrad and Hubbard Fellow Jasmine Cutter have both helped us compare small mammal populations between restored and remnant prairies. This table is from Jasmine’s data from one site, showing the number of trapsites in which each mammal species was caught back in 2014. In general, we’re finding that the same species are in both restored and remnant prairies, but the relative abundance of those species is often different – with some apparently favoring remnant habitat and others favoring restored areas.  We’re now looking at how our management affects presence and abundance of each species through time.

We've had several research projects look at native bees in our prairies. Mike Arduser, Anne Stine (Hubbard Fellow), Bethany Teeter, and Shelly Wiggam Rickets have all helped us compare restored and remnant prairies. So far, we've found over 72 species and the vast majority have been in both remnant and restored prairie.

We’ve had several research projects look at native bees in our prairies. Mike Arduser, Anne Stine (Hubbard Fellow), Bethany Teeters, and Shelly Wiggam Rickets have all helped us compare restored and remnant prairies. So far, we’ve found over 72 species and the vast majority have been in both remnant and restored prairie.

I've collected more than 15 years of data showing that plant diversity and the frequency of occurrence of prairie plant species has remained stable through time. These four graphs show four species in one restored prairie where we're comparing fire/grazing management to fire only management.

I’ve collected more than 15 years of data showing that plant diversity and the frequency of occurrence of prairie plant species has remained stable through time. These four graphs show four species in one restored prairie where we’re comparing fire/grazing management to fire only management.  The long-term persistence of prairie plants and diverse plant communities is critically important for plant communities, but also for the success of efforts to defragment habitat for animals.

These results mean that where prairie landscapes have been largely converted to row crops, we don’t have to just watch while insect or small mammal populations careen toward local extinction in tiny isolated prairies.  We’ve shown that we can make those prairies larger and more connected, and that animal populations can grow and use new restored habitat and diverse plant communities.  We’ve also shown that restored prairies can sustain their biological diversity for decades, even through periods of intensive grazing and drought.  While there are still plenty of questions and potential improvements we can make, we’re now at the point where society needs to decide whether and where to do this kind of restoration.

I don’t know about you, but I think that’s pretty exciting!

Nebraska and other states in central North America have large swaths of productive and important cropland.  As I said earlier, I’m not advocating that we convert most of that back to prairie.  However, there are specific sites where row crop agriculture is marginally productive/profitable and the long-term interests of both society and local landowners might be best served by putting land back into diverse and productive grassland.  Agricultural policies and subsidy programs will obviously play a huge role in this kind of strategic large-scale restoration, and getting the policies in place to facilitate this kind of common sense restoration will be plenty difficult.  That’s nothing new, however.  What’s new is our confidence that if we can implement targeted restoration work, it can make a real difference to prairie conservation.

Restoring the viability of prairies in fragmented landscapes is critically important to prairie conservation success.  The challenges of conserving species in small isolated prairies are immense, and many of those prairies will continue to see declines in biological diversity and ecological function over time unless we can make them bigger and more connected with other prairies.  Helping to document our ability to do that – at least for many prairie species – has been one of the most satisfying things I’ve done during my career.

 

Important footnote:  Restored prairies are not the same as remnant unplowed prairies.  Soil organic matter levels, for example, can take many decades to recover from tillage, and relationships between plant and microbial communities may take just as long to become reestablished.  Our success in prairie restoration should definitely not be used as justification for plowing up remnant prairie!  However, it’s equally true that prairie restoration efforts aren’t failures just because they can’t create an exact replica of prairie as it existed before it was converted to farmland.  If defragmenting prairie landscapes is the primary goal of restoration, we just need to create restored prairies that complement – not copy – remnant prairies. 

 

Hubbard Fellowship Blog – The Trouble With Fences

This post is written by Dillon Blankenship, one of our two Hubbard Fellows.  

Back in December we kept pretty busy with fence work. The barbed wire fences at a few sites needed to be repaired, and some had to be taken down and rebuilt from the beginning. Single wire electric fences were taken out altogether and will be replaced this spring to accommodate new grazing configurations.

The barbed wire fences we removed were old and in bad shape. Their wire was loose and rusty; t-posts were bent over or leaning.

When we acquire properties, fences are often in bad shape.  This one has multiple layers and ages of barbed wire and needs to be removed and replaced.

When we acquire properties, fences are often in bad shape. This one has multiple layers and ages of barbed wire, has shrubs and trees grown into it, and needs to be removed and replaced.

I am struck by how dramatically the landscape is changed by the mere removal of a fence. Despite the remaining row of interspersing trees or scraggly smooth brome, fencelessness returns a semblance of the infinite horizon. Of course, I want to see the trees and brome erased too, but these things take time and getting the old fence out of the way begins the process.

Even when the next piece of land is a dusty field of corn stalks – much less imposing post-harvest- the lack of fence is liberating. I am free to view the landscape as it once was and I imagine that wildlife can more freely roam about the planet.

Though it is easy to romanticize the open range, fences obviously have some utility.

Barbed wire fencing is a relatively inexpensive way of delineating property boundaries. It confines one’s own livestock and/or protects crops and pasture from being damaged (by stray vehicles, your neighbor’s cattle, etc.). In our restoration work on the Platte we use fences not just to keep cattle in, but also (using single strand electric) to manipulate where and when they graze to suit our particular management objectives – such as controlling certain plant species or promoting others while maintaining a diversity of habitat types.

m

Barbed wire fence is the most common type of fence used in most pastures.  It is strong and effective.  It is also visually prominent, and whether or not it is attractive depends upon your point of view.

Though these are compelling reasons to keep fences around, I remain frustrated by the inconveniences they create. I have already mentioned the aesthetic inconvenience. To my eye – even with agriculture playing a prominent role in the landscape mosaic – the Plains look more expansive and beautiful without fence lines. The image of an unfenced pasture is striking for its rarity.

Fences can also be problematic for certain wildlife. While deer are pretty good at jumping over most fences, animals further west like bighorn sheep and pronghorn need special accommodations for safe passage. Free-roaming bison, of course, have little hope in our highly fenced world – we must confine them to their own big area saying “this is yours, but go no further.” Even birds are affected, sometimes colliding with and becoming entangled in barbed wire. Field fences, though not insurmountable, present their own challenges for ground dwelling creatures.

This duck got hung up and died on a fence along the edge of a wetland.

This duck got hung up and died on a fence along the edge of a wetland.

My biggest complaint is that fence lines are often poorly managed. They can be difficult to work around when treating invasive species, which makes them prime habitat for encroaching trees and exotic plants. Substantial tree lines are common along fences in central Nebraska. In many cases, I suspect the fence came first. While a fence itself is usually not too problematic from a grassland habitat perspective, fences that grow up with trees begin to act as fragmenting agents – deterring grassland bird nesting and generally diminishing the openness favored by grassland species.

So where does that leave us?

There are already a lot of good ways to mitigate fence impacts for wildlife – increasing visibility for birds and using smooth wire with particular spacing for large mammals. Sometimes wooden fences are better alternatives, though more resource intensive (got any spare cedars?). While these address the wildlife objection, they don’t do much for the aesthetic or management elements.

Single-strand, smooth wire, electric fences are simple and temporary, offering reprieve from the oppressive four-strand barriers and better accessibility for management – you can drop the wire and drive right across. Moreover, when you move these fences every year like we do, fence-line management is less of a problem because the following year any given line-site will be back in the management regime of fire, grazing, and manual treatment. This system suits my preferences well, but its greatest assets are also its ultimate downfall.

Even when electrified, single wire fences are often not enough to keep cows in – and, I imagine, never keep in sheep or goats. Also, deer are pretty good at going right through, knocking the wire off the insulators – which is hard to monitor when you have a lot of wire out there. I was going to say that their temporary-ness was another drawback – a guarantee that you have to work fence every year. However, tree and exotic species management need to happen every year anyway, so maybe it wouldn’t be that much work and I feel like removing 20 years of trees from an unmaintained fence probably takes much more time than monitoring and moving temporary fences.

Bison fence at The Nature Conservancy's Broken Kettle Grasslands in Iowa.

Bison fence at The Nature Conservancy’s Broken Kettle Grasslands in Iowa.

My dream of fencelessness is really thwarted at scale. At places like TNC’s Niobrara Valley Preserve with over 50,000 acres to manage, you really just need a sturdy fence that doesn’t have to be constantly checked… or so I thought. I recently learned about innovations in fencing that have been experimented with over the last decade. I had been thinking that something like the invisible fences people use for pets might be an interesting option to scale up, but there are better systems already in play.

Instead of building (or burying) an actual fence, there are folks putting GPS collars on cows and then using digital mapping software to “draw” fences on the landscape which deliver a slight shock (like an electrified fence) when cows cross the satellite-imposed boundary. These digital fences can be placed at property boundaries, around sensitive vegetation or aquatic features, and across a pasture to suit a particular grazing regime – all with the swipe of a computer cursor. It could be modified on the fly, which is even easier now that so many people are carrying smartphones (this technology is already being utilized for things like increasing center pivot irrigation efficiency via monitoring and adaptive management). Doesn’t that sound incredible? No fences breaking up the landscape (which is aesthetic, but also means less work for ranchers), safer corridors for wildlife, less potential for tree encroachment, and better accessibility for managing invasive weeds. Cool.

The system is bound to have its own problems – technical glitches will happen on occasion (with the software or and the collars), there will be new opportunities for trouble-makers to tamper with private property (“digital cattle rustlers”), star-up costs, you name it – but I really like the potential something like this has for prairies and the ranching community.

Nonetheless, most of us aren’t quite there yet, which brings me back to the old-fashioned fence. For now I guess I’ll have to get over it and get on to other things; just manage my own fence better and become hardened to the unavoidable taunting of unnatural tree lines and fence rows on the landscape.

It feels good to vent a little bit here. As it warms up I cease writing and return to work on the post and wire repairs. I return to the prairie and reflect on these musing, “Alas, this is a necessary, if unfortunate evil” and the new fence goes up. I find solace that its days could be numbered.

ENPO130523_D002