Tag Archives: grazing management

Choosing Your Destination Before You Choose Your Mode of Transport

Posted on by
18

Last week, I attended a science and stewardship conference of The Nature Conservancy in Madison, Wisconsin.  It was an inspiring and thought-provoking week.  There were a lot of topics that will provide fodder for future blog posts, but I wanted to start with an issue that came up in several sessions.  The topic had to do with setting appropriate objectives for conservation strategies, and for land management in particular.  In short, it’s really important to make sure we’re not setting objectives that are focused on strategies rather than outcomes.

This mixed-grass prairie is managed with both prescribed fire and grazing.  However,  neither fire nor grazing is the objective, they are tools that are strategically employed to create desired outcomes.  Gjerloff Prairie – Prairie Plains Resource Institute

Here’s an illustration of what I mean.  If I was planning a vacation for next summer, I probably wouldn’t start with the following question: “What mode of transportation should I take on my vacation next year?”

Clearly, it’s tough to answer that question without knowing more about the ultimate objectives of the vacation.  Where do I want to go?  What time of year am I going?  How many people are going with me?  If I’m planning to travel from Nebraska to Ireland, I probably won’t be able to do that by bus.  I could conceivably travel by motorcycle (if I had one) to the Rocky Mountains, but probably not if I was going during the winter or planning to take little kids with me.

It seems silly to start by thinking about how to get somewhere before deciding where to go, but as land managers, it’s easy to fall into exactly that mindset.  We sometimes set objectives about using fire or grazing, for example, instead of first defining the outcome we want and then thinking about what tools and strategies might get us there (which may or may not include fire or grazing).  In this post, I’ve provided examples of how this trap can present itself, both to managers of conservation land and private landowners, and some thoughts about how to avoid the trap.

Significant research has helped us understand the kinds of fire and grazing patterns under which North American prairies developed.  For example, in many places, we have a pretty good idea how often a particular site burned, on average, before European settlement.  We also have reasonably good information on the presence, abundance, and behavior of historic grazers.  Based on that information, a land manager could decide that the best management for their prairie would be to reinstate, as closely as possible, the timing and intensity of historic fire and grazing that site likely evolved under. 

Historically, prairies in this region probably burned on an average of every 4-5 years.  However, within that average range, there would have been wide variation.  More importantly, this prairie sits within a very different landscape today, with challenges not faced by those historic prairies.

Patch-burn grazing is often described, for example, as “mimicking historic fire and grazing patterns.”  Mob grazing advocates trumpet (though I’m skeptical) that their system replicates the way bison moved across a landscape.  Some in the Upper Midwest region of North America point to research showing high populations of indigenous people and scarce evidence of abundant bison and argue that their prairies should be managed only with fire.  We can argue about all three of those examples – and many more – but the bigger point is that none of those arguments should determine our management strategies.  Again, we shouldn’t be setting objectives about the strategy we want to use without first identifying the outcome we want.

To make a clunky return to my vacation travel analogy, it would be silly of me to choose horseback as my preferred mode of transportation across the Great Plains to the Rocky Mountains just because it’s what worked several hundred years ago.  Today’s landscape is broken up into countless fenced off private land parcels, which would make cross-country horse travel difficult, to say the least.  In addition, there is a pretty nice set of modern opportunities (roads and vehicles) I can take advantage of nowadays.

Likewise, our prairies exist within a different world today, with a new set of challenges and opportunities.  Mimicking historic disturbance regimes won’t necessarily keep prairies in good shape in a world with habitat fragmentation, massive invasive species pressure, climate change, nitrogen deposition, and other factors.  And speaking of good shape, our first and primary concern should really be to define what “good shape” is, right?  Are we managing for plant diversity or a few rare plants?  Are we trying to sustain diverse bird populations?  Habitat heterogeneity? Is ecological resilience the goal?  If so, what are the factors driving resilience, and how to we sustain those?  There are countless reasonable goals for land managers to choose from, many dependent upon scale, but those goals should be based on the outcome we want.

This annually-hayed prairie maintains high plant diversity but provides only one type of habitat structure for nesting birds and other wildlife species.  Depending upon the objectives for the site, that could be fine, but it very much depends upon what the manager wants to accomplish.

I feel it’s important to say this here:  I am a big proponent of both fire and grazing as management tools – you can find myriad examples of that by searching through my previous blog posts.  However, while I think combining fire and grazing can create some fantastic results, those strategies/results don’t fit all objectives.  More importantly, your particular site may or may not respond well to those kinds of fire and grazing combinations.

Let’s say your primary objective is to provide habitat for as many species of grassland birds as possible.  First, you’ll need a pretty big swath of land – many bird species have minimum habitat size requirements.  Assuming you’ve got sufficient land, the major factor grassland nesting birds respond to is habitat structure.  Some birds prefer tall thatchy structure, others like short/sparse vegetation, and others want something in-between.  A reasonable outcome-based objective might be that you want to provide all three of those habitat types across your prairie each year (and you’ll want to make sure the habitat are being successfully used by a diverse bird community).  Perfect.  Now, how will you create those habitat types?

 Grasshopper sparrows tend to nest in prairies with relatively short structure, but with some thatch (which they use to build nests) along the ground.  Some of the highest abundances of grasshopper sparrows around here are found in relatively heavily-grazed prairie.

Fall or spring fires can create short habitat structure that some birds really like to nest in.  However, some bird species (e.g., grasshopper sparrows) usually like short habitat with a little more thatch in the ground layer than is usually found in recently burned prairies.  Also, while burned areas are short and unburned areas are tall, it’s difficult to create in-between height/density habitats using only fire.  This is where other tools such as mowing and grazing might be helpful.  Mowing can reduce the height of tall vegetation and create short or mid-height structure that grasshopper sparrows, meadowlarks, and other species prefer.  Grazing can do the same and can have the advantage that cattle or bison are selective grazers, eating some plants and leaving others.  This can create structure with both tall and short vegetation mixed together and can also help suppress grasses and allow for greater expression of forbs (broadleaf plants) – something birds such as dickcissels often prefer.

Upland sandpipers prefer to nest where vegetation structure is short, but often move to sites with strong forb cover and a little patchier structure when their chicks become active.

If we’re trying to create optimal bird habitat, then, fire, mowing and grazing might all be useful tools to consider.  It’s important to understand how each tool can be used to affect habitat structure, as well as the potential risks of using each (fire can sometimes kill aboveground animals and stimulate invasive plants, grazers can sometimes target vulnerable plants and create issues via trampling).  With all of that information, you can start putting together strategies that employ the right tools, and then test those strategies against the OUTCOMES you desire.  Notice that the process I’ve just described is independent of the kinds of historic fire returns for your area or whether or not you think grazing was a significant factor in the evolution of regional plant communities.  Define your objective by the outcomes you want and test/adapt strategies based on that objective.

Other examples: At my family prairie, we aren’t using prescribed fire because we’ve been able to use grazing to meet our objectives of habitat heterogeneity and increasing plant diversity, and we use loppers/herbicide to successfully control woody invasion.  In small prairies where preserving particular plant species is the objective, a strategy using only fire or mowing could be most appropriate.  If that small prairie has rare insects or reptiles that are especially vulnerable to fire, maybe mowing is the best tool.  Regardless, the right tools and strategies depend upon the outcome-based objective.

This photo was taken in the burned patch of a patch-burn grazed prairie at Konza prairie, near Manhattan, Kansas.  The grazing created varied habitat structure because of the selective grazing by cattle.  Leadplant and other ungrazed forbs contrast with surrounding short grasses.

For ranchers and farmers who manage prairies, this same objective setting process should apply, but of course those prairies also have to help provide sufficient income to keep a family or business thriving.  Even in those cases, however, it’s still important to start with outcome-based objectives.  Those objectives can include a certain amount of needed income but should also include specific habitat or other ecological objectives.  Once you’ve decided, for example, that you really want to manage in a way that provides a certain amount of quail habitat or provides consistent pollinator resources through the season, you can look for ways to accomplish that while still providing the needed income.  When a conflict between income and habitat objectives arises, you can make the decisions that make sense to you, but at least you’re making those decisions with all the information needed to fully consider the options.

Prescribed fire can be a great tool for accomplishing some objectives, but it can also be difficult to implement for some managers.  While it is an important ecological process in prairies, employing prescribed fire should still be seen as a tool/strategy, rather than as an objective in and of itself.

There are plenty of reasonable prairie management objectives to choose from, but they should be based on outcomes rather than on tools and strategies.  Employing more frequent prescribed fire is not a good objective.  However, using more frequent prescribed fire might be a great strategy to reach a particular outcome.  (It could also be a terrible strategy, depending upon your objective.)  Don’t fall into the trap of choosing your transportation method before you know where you want to go. 

P.S. I’m sure some of you are thinking it, so let me address what might appear to be a weakness of my vacation transportation analogy.  Yes, it’s perfectly fine to start vacation planning by deciding that you want to take a cruise ship or motorcycle if the OUTCOME you really want is to ride on a ship or motorcycle.  If you don’t care where you go, the destination isn’t the outcome, it’s just a by-product of your mode of travel.  Fine.  But I think you understand what I was trying to say, right?  Sure, you could argue that conducting prescribed fires could be your objective if all you want is a legal way to light things on fire and watch them burn.  If that’s your objective, though, you’re not managing prairies, you’re lighting things on fire – and there’s a big difference.  Ok?  Ok.

How I Manage My Own Prairie

Posted on by
10

One of our major objectives at the Platte River Prairies is to experiment with and demonstrate various prairie management techniques and strategies.  All those strategies are aimed at creating and maintaining plant diversity, ecological resilience, and a wide range of wildlife habitat types.  We hope that our work can be useful to private landowners and other grassland managers looking for ideas to incorporate into their own management.  However, we don’t expect anyone to replicate exactly what we’re doing because every land manager has their own set of objectives for their land.  As an example of how others might incorporate some of the lessons we’re learning into a different setting, I thought I’d share how I’m doing that at my family prairie.

My family prairie is very different from the Platte River Prairies in several respects.  First, the Helzer prairie is on hills of loess (pronounced “luss”) soils, whereas the Platte River prairies grow in sandy loam.  In addition, most of my prairie was farmland until my grandpa seeded it back to grass in the early 1960’s.  There are a few small areas of remnant (unplowed) prairie embedded within the previously farmed area, and some plant species have spread from those.  However, plant diversity is still fairly low, so I’ve been supplementing that by adding seed of more plant species over time.

This is one of the more diverse portions of our prairie - a part that was never plowed. It still has plants such as leadplant, stiff sunflower, and many others.

This is one of the more diverse portions of our prairie – a part that was never plowed. It still has plants such as leadplant, stiff sunflower, and many others.

The most important difference between my prairie and the Platte River Prairies, though, has to do with my objectives.  At the Helzer prairie, I want plant diversity and wildlife habitat, but I also need strong and steady income from my prairie to cover the taxes and contribute to our family’s finances.

Objectives for the Helzer family prairie:

  1. Increase plant diversity.
  2. Create a wide range of grassland habitat types each year (short/sparse to tall/dense and intermediate stages).
  3. Provide a place my family and I can enjoy.  I want my kids to hike, explore, camp out, and learn about prairies and agriculture.
  4. Make money.

Recreation is part of our objectives for the prairie, but income is also very important.

Recreation is one of our objectives for the prairie, but income is also very important.

Challenges:

  1. Poor soils – much of the organic matter in the soil, especially on slopes, eroded away when it was farmed and even more then 50 years of grassland cover has not rebuilt what was lost.
  2. Soil erosion.  Because loess soils are easily erodible, heavy rain can wash exposed soil from both the crop fields and heavily grazed areas of our pasture, causing a number of problems.  No-till farming techniques on the crop fields reduce erosion from them, but we also have to be careful about how we graze the prairie to avoid losing soil from the steeper slopes.
  3. Invasive species – smooth brome and Kentucky bluegrass are the big ones, and they can become dominant enough to swamp out plant diversity if left unchecked.
  4. Tree encroachment.  Eastern red cedar trees are constantly trying to colonize the prairie.  We’ve removed all the big cedar trees from our own property, but others nearby produce seed that birds helpfully carry into our prairie.  Deciduous trees such as honey locust, white mulberry, and green ash also spread into the prairie unless we beat them back.
  5. Habitat fragmentation.  Our prairie is truly an island of prairie in a sea of cropland.  We own about 160 acres of land, about 50 of which is in crops.  That leaves us roughly 110 acres of prairie on which we have to support populations of prairie plants and animals, and we can’t rely on the surrounding landscape as a source of recolonization if we accidentally wipe any of them out.

So, what to do?

Trees

Controlling the encroachment of trees, especially cedar trees, is pretty straightforward – we just cut them down as they come in.  We use herbicide on the stumps of deciduous trees, but with the cedars, my kids and I just roam around with loppers and snip the little ones off.  As long as we don’t get behind, it doesn’t take too much time, and it’s not hard work.

My son John, when he was 9, helping us clear cedar trees.

My son John, when he was 9, helping us clear cedar trees.

Of course, controlling cedars would be even easier if we were using fire, but we’re not.  (Surprised?)  I’d love to burn my prairie, but there are a two big reasons I don’t.  First, I don’t have any equipment for conducting my own burns – not even a drip torch.  I could probably borrow some equipment and find some people to help me burn if I really tried.  However, the bigger reason I don’t burn is that there are only so many days a year when weather conditions are appropriate for burning, and on those days I’m burning at work!  Maybe someday when I retire…  In the meantime, we’re getting by with loppers and cows.

Grazing Plans

This is the real heart of our management, and the part that takes the most thought and adjustment over time.  The first consideration every year is drought.  We live in a part of the country where droughts are frequent, and drought impacts our prairie particularly strongly because we have so little organic matter (which helps hold soil moisture) in the previously farmed portions.  As a result, I assume every year will be a drought year until I’m proven wrong, and my stocking rates are based on that assumption.  If we have a wet year, I can increase our stocking rate the next year to take advantage of the bonus root reserves produced by “undergrazed” grasses.  However, by stocking relatively conservatively, I can usually get through very dry years without overgrazing or putting an undue burden on my renter by making him pull his cattle off early.

A map of our 160 acres of land, including both cropland and grassland. The prairie is split into four main pastures. The blue dots show water tanks that we recently installed.

A map of our 160 acres of land, including both cropland and grassland. The prairie is split into four main pastures. The blue dots show water tanks that we recently installed.

Apart from drought, my main grazing strategy is to incorporate the concept of a “shifting mosaic of habitat types” across my prairie.  In the Platte River Prairies, we often accomplish this with various patch-burn grazing techniques, but I don’t use fire on my own prairie.  Instead, we have the prairie split up into four main pastures (and a couple smaller sites in and around the pond/wetland that are rarely grazed).  The way we utilize those four pastures changes every year based on what happened the year before and on short-term objectives, but there is a basic framework (shown below) I’ve been using for the last several years.

TEMPLATE GRAZING PLAN FOR THE HELZER PRAIRIE

Year 1                                                                              Year 2

Late April – Early May: Pasture #1                       Late April – Early May: Pasture #2

Early May – June 1: Pasture #2                             Early May – June 1: Pasture #3

June 1 – July 15: Pasture #3                                   June 1 – July 15: Pasture #4

July 10 – October 1: Pasture #’s 1, 3, and 4       July 10 – October 1: Pasture #’s 1, 2, and 4

A graphical illustration of my grazing plan framework. In Year 1, pastures 1 and 2 are grazed early to knock back brome. Then pasture 3 is grazed for a month by until mid-July. For the remainder of the season, cattle have access to three pastures, but continue to graze pasture 3 most intensively because of the attractive regrowth of the grasses there. This creates a system fairly similar to a patch-burn grazing system, but uses a grazing enclosure, rather than fire, to create attractive forage and concentrate grazing.

A graphical illustration of my grazing plan framework.

 

During Year 1 in the above example, pastures 1 and 2 are grazed early to knock back brome. Pasture 3 is then grazed until mid-July. For the latter half of the season, cattle have access to three pastures, but will continue to graze pasture 3 most intensively.  This is because the vegetation in pastures 1 and 4 was ungrazed during June/July and reached a later stage of maturity (and is less palatable) than that in pasture 3, which is still relatively young and tender because of the grazing.  In other words, the earlier season grazing stimulates later season grazing.

This creates a system somewhat similar to a patch-burn grazing system, but without the use of fire.  Pasture 3 gets grazed intensively for most of the season in Year 1, but pastures 1 and 4 provide “overflow” grazing to help ensure that pasture 3 isn’t grazed excessively.  That overflow also seems to limit wildflower grazing because the cattle aren’t forced to eat only from one pasture and can wander more broadly to find what they really want – mostly grass.

In Year 2, pasture 3 is rested (after a brief spring grazing bout to suppress brome) and pasture 4 has a year of intensive grazing.  The pattern continues in Year 3 and Year 4 and then (probably) starts over.  When everything works as planned, there’s always one pasture that’s short, one that’s got fairly tall vegetation, and another one or two in various phases of recovery from being grazed in previous years.  Even plants strongly sought after by cattle get a chance to bloom and reproduce at least once every four years, and most bloom much more often.

I’ve had to adjust my approach to grazing over time to be sure I don’t overexpose the prairie to soil erosion.  As a result, I graze a little less intensively than we do in our (mostly) flatter/sandier Platte River Prairies.  I really like the plant diversity and habitat results I get from season-long intensive grazing and multi-year recovery periods, but have had to moderate that somewhat as I’ve learned more about what the soils can take.  I still take the grass pretty short, but limit the length of time it’s kept that short – especially in parts of the prairie most prone to soil erosion.

Overseeding

Introducing seed to increase plant diversity over time is an important part of our restoration/management process.  My grazing management is facilitating the spread and survival of the plant species we have, but there’s limited abundance and diversity to work with.  My kids (sometimes) help me harvest seeds from around the county during the summer and fall.  During the winter, we broadcast those seeds in the pasture most heavily grazed during the previous year – where they can make contact with the soil where they fall.  That pasture is typically grazed the next spring, and then rested for the remainder of the year.  As a result, seedlings have a decent chance of survival because the surrounding vegetation was weakened by grazing, but they are not exposed to (much) grazing during their first season of growth.  So far, results from overseeding have been encouraging – we’re just limited by the time we have to harvest seed.

Here's Daniel, throwing seeds into an area that was grazed intensively the previous season.

Here’s Daniel, throwing seeds into an area that was grazed intensively the previous season.

By far, the most critical aspect of my management is adaptability.  While there is a basic framework for our grazing management, I don’t hesitate to stray from it in order to react to drought or invasive species concerns, or because it just looks like we need to try something different.  The pasture that gets the most intensive grazing each year is the one that has recovered most fully from its last intensive grazing bout.  That recovery time depends upon the stocking rate when it was grazed and the weather during and after that grazing period.  Most importantly, I try to ensure that all the plant species in the prairie are allowed to bloom at least once every few years (without getting their flowers nipped off) and that we always have a wide range of habitat structure (short, tall, and recovering vegetation) across the prairie.  If I see issues with either of those conditions, I adapt my grazing management accordingly.

There is no cook book for how to manage a prairie because every prairie and every prairie manager’s objectives are different, and those unique conditions require unique strategies.  However, I do think there are broad lessons about how to facilitate wildlife habitat and plant diversity (such as the “shifting mosaic of habitat patches” idea), and those lessons can be applied to almost any situation.  The trick is to figure out how to adapt them for an individual site and set of objectives, and to continue adapting them as weather and other conditions change.  In my case, I’ve come up with a system that works pretty well for my particular prairie and objectives, as well as with the time and equipment I have.

As I said earlier, I don’t want people to replicate the management we’re using in the Platte River Prairies.  Instead, I am always thrilled to hear that other land managers have picked up ideas from us and incorporated them into their own grassland management.  Hopefully, those ideas have helped those land managers increase plant and wildlife diversity on their land, while still meeting their other objectives.  That would make me very happy.