Choosing Your Destination Before You Choose Your Mode of Transport

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 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.

What’s the Best Time to Burn?

As I mentioned last week, prescribed fire can help meet many prairie management objectives.  It’s important, however, to match the timing of the burn to those objectives in order to avoid conducting a fire that is either unproductive or counterproductive.  For example, if you’re burning to set back trees or invasive plants, you’ll want to be sure to burn when the fire will suppress those species and encourage growth of competing plants.  Too many times, people burn to control smooth brome or another invasive cool-season grass but burn so early in the season that they end up helping the plants they’re trying to hurt.  Here are some examples of various management objectives for prescribed fire, along with examples of how to time those burns to meet those objectives successfully.

dormant
This early March burn (dormant season) will stimulate the growth of cool-season invasive grasses such as smooth brome or Kentucky bluegrass.  However, we brought in cattle to knock back the strong growth of those species.

In the Platte River Prairies, our biggest invasive species threat comes from smooth brome, Kentucky bluegrass, and other invasive grasses that grow early in the season.  They can monopolize space and moisture, reduce plant diversity and wreak havoc on habitat conditions.  When we target those species with fire, we try to burn when the targeted species is just about to bloom.  By doing so, we can knock the brome or bluegrass back after it has invested energy in growth but before it invests in reproduction.  At the same time, we create excellent conditions (lots of light and warm soil) for competing warm-season native species which are just getting ready to start their growing season.  Bluegrass blooms significantly earlier than brome, so we can’t get maximum impact on both species with one burn.  Instead, we have to decide which is the more dominant grass at the time.  Regardless, the timing of our burn is aimed at the growth stage of the plant, not a particular date, since plant growth rates vary by year.

One issue we’ve seen with using fire to control brome or bluegrass is that while we can suppress those cool-season grasses and facilitate growth of warm-season native grasses, we often just trade one dominant grass for another without encouraging overall plant diversity.  As a result, we often combine cattle grazing with fire to add a more selective defoliator (cattle) to the mix.  When we’re using grazing, the timing of the fire can be more flexible.  We can conduct a burn in the fall or early spring, and while that will stimulate strong growth of brome and bluegrass, we can use intensive spring cattle grazing to counter that strong growth and suppress those invasives.  Later in the summer, a fairly light stocking rate of cattle can help suppress major warm-season grasses and keep them from simply taking all the space left open by weakened invasive grasses.  This creates opportunities for wildflowers to flourish.  Since cattle prefer big bluestem and indiangrass over all other plant species in our summer prairies, that kind of grazing usually works pretty well.  There are too many potential combinations of fire and grazing to cover here, but suffice it to say we can burn at many times of the year when using cattle to complement the effects of those fires.

bluegrass
This fire was conducted at about the time Kentucky bluegrass was starting to bloom, so it should knock the vigor of that species back for a year or two.

If cattle aren’t an option but you find that fire alone just encourages dominant grasses of one kind or another (a more common result in the Great Plains than in the Midwest), one option could be a summer fire.  If you’ve never seen a summer prescribed fire, you might find it hard to believe that green prairie can burn, but as long as there is sufficient old growth from previous seasons that dead vegetation will carry a fire, regardless of how green this year’s vegetation is.  (That green vegetation does make summer fires extra smoky, however.)  If big bluestem is the dominant species you want to suppress, the best time to burn is when it’s just ready to bloom.  Remember that there are many other factors to consider with summer fires, including the various animals that are active in the prairie at that time of year.  It’s usually best to burn only a small portion of a prairie in the summer to avoid excess impacts on wildlife and invertebrates.  However, summer fires can be very good for encouraging wildflower growth, and the habitat benefits from added plant diversity help counteract short-term impacts of the fire on animals.  Another caution with summer fires is that if cool-season invasive grasses are a problem at a site, they will likely benefit from a summer fire, and could thrive during the following fall and spring without some other treatment.

Controlling trees with fire is a common objective for prairie managers, but timing is also important for that objective – and appropriate timing varies by the species of tree being targeted.  We’ve had some very good late spring burns that suppressed brome wonderfully but failed to kill small eastern red cedar trees.  I think the trees failed to die because there was insufficient heat created to make up for the increased moisture in the stems at that time of year.  The trees turned yellow-orange after the fire but then greened up again.  We’ve found dormant season fires to be far more successful when we’re targeting cedars.  On the flip side, it seems like we’ve had the best luck suppressing (but not killing) dogwoods and other deciduous trees and shrubs when we burn as those species are just leafing out later in the spring.  However, our success with deciduous plants has been inconsistent enough that I hate to make recommendations – and deciduous tree control with fire is usually temporary at best.  Dirac Twidwell, range ecologist at the University of Nebraska-Lincoln, has experimented with intense summer fires during drought conditions in the southern plains and has found that the combination of high temperatures and drought stress can be deadly on trees not ordinarily considered to be susceptible to fire.  Unfortunately, burning under those conditions takes much more training and preparation (and more trusting fire chiefs) than most of us can muster.

cedar
This cedar will probably survive this growing season burn.  It turned yellow but will likely turn green again and continue its growth.

Dormant season burns include any fires conducted after the prairie turns brown in the fall and before it greens again in the spring.  Impacts from late fall and early spring burns are pretty similar to each other, with the caveat that fall burned prairies have bare ground all winter long, which can dry out the soil somewhat and – obviously – provide very different winter habitat than prairies with standing vegetation for species that need that.  Drier soil and bare ground are not necessarily bad things, especially if there is other prairie habitat nearby.  In fact, some managers in northern parts of the United States have found that bare soil over the winter can help winter kill Kentucky bluegrass during particularly cold winters.  Fall or winter burning can also help extend the window needed to find the right weather to conduct a dormant season burn.  Depending upon your objectives, those fall burns could be just as effective as an early spring burn and you can relax all winter, knowing that your burn is already done.  One additional consideration with fall burns is that the day length (at least in North America) is considerably shorter in November than in March, giving you less time to conduct a fire during daylight hours.

There are many other possible objectives for prescribed fire, and examples of how to achieve them.  Those of us who harvest seed for restoration work, for example, use fire to stimulate seed production in some species (especially big bluestem).  In addition, because time since the last fire is linked to the amount of thatch and litter present in a prairie, burning can help manipulate habitat conditions for many wildlife species.  Speaking of wildlife, it’s critically important to remember how vulnerable some invertebrates and animals are to fire and to keep that in mind when setting burn objectives.  Burning an entire prairie (especially one that is isolated from others by roads or other obstacles) can completely eliminate some species of invertebrates that are aboveground during the fire – including many that overwinter in standing dead vegetation.  Depending upon your other objectives, you might consider not going into a burn unit to light all the patches of vegetation that didn’t burn initially – leaving those unburned areas can provide important refuges for vulnerable insects and other critters.  In addition to invertebrates, nesting birds, recently emerged reptiles in the spring, and other less mobile animals are all species to consider as you plan growing season burns.  There will always be negative impacts of any fire, but they should not be reasons to avoid burning.  Instead, they are examples of why it’s so important to have clear objectives so that you make sure you get the desired benefits from the fire and minimize the undesirable outcomes.

refuges
This growing season burn left behind numerous unburned patches, providing refuges for invertebrates and other small animals.

Fire is a powerful but dangerous tool for prairie management.  While it can be very useful for a wide range of objectives, there are too many risks (to people, property, and wildlife) to use it in a cavalier manner.  Setting specific goals for a fire and being thoughtful about the timing and tactics for that fire will help ensure that it is as productive as possible.

Be safe out there.

Report from the 2013 Grassland Restoration Network Workshop – Part 1

The Grassland Restoration Network’s annual workshop took place a couple weeks ago in Columbia, Missouri.  This year’s workshop was hosted by the Missouri Department of Conservation and included more than 90 people from around the country.  As always, the meeting was a mixture of presentations, discussions, and field tours, and was informal enough that we had plenty of time to get to know each other and catch up on what everyone has been learning at their own sites.  There were too many topics and discussions from the workshop to cover in a single blog post, so I’ll spread them out over the next several weeks or months.

Attendees of the Grassland Restoration Network's annual workshop at Tucker Prairie, east of Columbia, Missouri.
Attendees of the Grassland Restoration Network’s annual workshop at Tucker Prairie, east of Columbia, Missouri.

One of the most intriguing discussions of the workshop was an extended conversation during our field trip to the 711 acre Prairie Fork Conservation Area, managed by Missouri Department of Conservation (MDC).  At several points during the trip, we talked about objectives for restoration projects and prairie plantings.  Here in the Platte River Prairies, our restoration objective is to use prairie plantings to enlarge and reconnect fragmented remnant prairies – hoping to increase overall ecological resilience and the viability of populations of plants, bees, etc.  At Prairie Fork, however, there are no remnant prairies to stitch together, and education is a major focus of their restoration project.  Their stated restoration goal is simply to rebuild natural communities and their processes.  Then they use those restored areas as platforms for their education work.

Although Prairie Fork Conservation Area is not far from Tucker Prairie – the last remnant of the once vast Grand Prairie that stretched across a large swath of Missouri – MDC staff are not trying to design their plantings to mimic Tucker Prairie.  Instead, they are harvesting seed from Tucker prairie and other small scattered areas of native prairie vegetation to create seed mixtures that are a composite of all of those sites.  As a result, prairie plantings are allowed to develop into communities as local site conditions allow – a very sensible approach.

Rattlesnake master is common at Tucker Prairie, the last sizeable remnant of the Grand Prairie that used to cover a large portion of northern Missouri.
Rattlesnake master is common at Tucker Prairie, the last sizeable remnant of the Grand Prairie that used to cover a large portion of northern Missouri.

The decision not to impose constraints on what each Prairie Fork planting needs to look like gives MDC considerable freedom in terms of evaluating success.  That freedom led to some great discussions about what success should/could look like.  There were three tour stops where the topic came up in some form, and each is worth discussing.

1. The first discussion occurred early in the tour when we were looking at a soybean field that was going to be converted to prairie vegetation within the next few years.  Around the edge of the field were “waste areas” of tall fescue with infestations of sericea lespedeza, autumn olive, and other invasive plants and trees.  Because of the trees and topography, it wasn’t feasible to put those areas into cultivation, which is the technique MDC (and most of us) would prefer as a way to create a clean seed bed prior to planting prairie.  The group starting talking about other ways those areas might be prepared for planting, until Bill Kleiman (with The Nature Conservancy’s Nachusa Grasslands in Illinois) abruptly shifted the discussion.

Bill made the excellent point that those difficult areas wouldn’t necessarily have to be converted to a diverse prairie planting, and that attempting to do so might prove to be overwhelmingly time consuming or simply impossible.  The seedbank of invasives in those areas is probably heavy enough that even multiple years of cultivation might still result in long-term fights with invasive plants emerging from that seedbank long after prairie vegetation was planted.  Instead, Bill suggested, why not implement an annual program of broadcast herbicide spraying in those waste areas – with the simple goal of maintaining them as a low diversity, grass-dominated, plant communities that won’t threaten nearby diverse plantings?  In other words, rather than trying to make those areas perfect, just make them harmless.  Down the road, when everything else is restored, MDC can always come back and spend energy trying to convert them to something diverse.  In the meantime, they can save a lot of time and energy by avoiding a (likely fruitless) battle to convert a very weedy area into a pretty prairie.  It was certainly an interesting proposal.

Rosinweed (Silphium integrifolium) was just beginning to bloom during the GRN workshop.
Rosinweed (Silphium integrifolium) was just beginning to bloom during the GRN workshop.

2. The next site we visited had been planted to prairie vegetation several years earlier, but had a chronic infestation of sericea lespedeza.  While MDC staff was controlling the lespedeza through spot spraying, there was enough lespedeza (and enough spraying) that the area’s plant diversity had become fairly limited and dominated by a few grass and wildflower species.  Chris Newbold, who had been in charge of the restoration work at the time the site was seeded, said that if he had to do it all again, he would have left the area in cultivation a few more years to get better control of the lespdeza population prior to planting.  The more pressing question now, though, was how to deal with the site going forward.  Options included starting over by returning it to cultivation, trying to overseed the area to establish better plant diversity, or just leaving it alone.  An additional proposal was to overseed with plant species that are resistant to a selective herbicide that controls lespedeza, allowing the site to be broadcast sprayed without eliminating all plant diversity.  I don’t think the question was resolved through our discussion, but we built upon our earlier conversation by posing the question, “Does every part of a restoration project have to be ‘perfect’ in order for the project to be successful?”

This portion of Prairie Fork Conservation Area was seeded with a high diversity mixture but has lost plant diversity , at least in part because of years of herbicide spraying for sericea lespedeza.  The lespedeza is spot sprayed, but is abundant enough that herbicide impacts are evident on the plant community.
This portion of Prairie Fork Conservation Area was seeded with a high diversity mixture but has lost plant diversity , at least in part because of years of herbicide spraying for sericea lespedeza. The lespedeza is spot sprayed, but is abundant enough that herbicide impacts are evident on the plant community.  Mike Arduser, of MDC, pointed out that the site looks really nice from a bee habitat standpoint, bolstering the idea that although it had lost some of its plant diversity, it was still an important contributor to the landscape around it.

I appreciated the discussion because it forced me to reflect upon our Platte River Prairies, and areas that I wish looked better than they did.  In both my prairies and at Prairie Fork, it’s really the big picture that’s important.  Within the mosaic of natural communities that make up any sizeable prairie, it’s probably ok to have areas of low diversity vegetation.  At least at the scale of Prairie Fork, it’s really the mosaic that’s important, and variation in plant species composition between individual portions of the landscape is not only acceptable, but preferable.  Coming to terms with the idea that it’s ok to have portions of our prairies/properties that are less diverse than we think they could be is an important part of being a successful land manager.  The alternative probably entails driving ourselves to exhaustion!

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3. The last site we looked at was a 2004 prairie planting that was very diverse and full of big showy wildflowers.  From an aesthetic standpoint, the planting was a big beautiful success.  I asked the MDC staff how they might judge the success of such a planting according to their objectives.  Clearly, one part of the answer is that a showy prairie is useful in terms of getting people to appreciate prairies – so that fits well into education/outreach objectives.  However, Jeff Demand, the current site manager, had another interesting perspective.  Jeff said that he appreciated the planting because it required very little maintenance.  There were no real invasive species issues to deal with, and nothing else about it that screamed out for attention.  The planting was clearly of value to wildlife, pollinators, and other prairie species, but it was particularly nice to have an area that just needed some period burning or similar management.  Especially when budgets and staffing are tight (and when are they NOT?) a site that is attractive and low maintenance can seem like heaven.

This 1994 seeding at Prairie Fork is an aesthetically-pleasing site.  Most people would be very happy to have this kind of establishment success from a prairie planting.
This 2004 seeding at Prairie Fork is an aesthetically-pleasing site. Most people would be very happy to have this kind of establishment success from a prairie planting.  However, aesthetics is not always the best measure of success.

There are no right or wrong answers when it comes to objectives.  Every site has its own, and they almost always change over time.  The important thing is to know what the objectives are for a particular site, and to be measuring whether or not you’re moving in the right direction.  It’s always nice to hear about other people’s objectives and measures, because it makes us re-examine our own.

I tend to worry more than I should about portions of our site that aren’t as “nice” as I think they should be.  The field trip discussion was a great reminder to sto obsessing about small areas and keep the big picture in mind.  It’s important to deal with areas that might negatively influence the surrounding landscape (e.g., by providing a foothold for invasive species that can spread into nearby areas).  Otherwise, however, variation between portions of a prairie or prairie landscape just adds to the diversity – and resilience – of the ecosystem.  I think that’s a good thing.

I guess I just have to be reminded of that now and then.

Difficult Decisions – Growing Season Fires and Other Prairie Management Choices

Would you purposefully destroy the nest of a wild turkey or grasshopper sparrow?  Of course not.  But what if that destruction was a consequence of a land management action that benefits the larger prairie community?  That was the situation we were faced with last week as we mulled over whether or not to conduct a late spring (early summer?) prescribed burn.

Michelle Biodrowski ignites a prescribed fire last week (June 6) at a wet-mesic prairie.  The Nature Conservancy's Platte River Prairies.
Michelle Biodrowski ignites a prescribed fire last week (June 6) at a wet-mesic prairie. The Nature Conservancy’s Platte River Prairies.

In the aftermath of any prescribed fire, there are winners and losers.  Fire rapidly and dramatically alters habitat and growing conditions in ways that favor some plant and animal species and put others at a disadvantage.  Fires also kill some insects and other animals outright.  For example, dormant season (late fall through early spring) fires burn up a lot of invertebrates that overwinter in prairie thatch.  Growing season fires, of course, can kill numerous small animals – especially slow-moving non-flying ones.  We usually don’t see the evidence of those impacts, but when we do, it’s no fun.  Over the years, I’ve seen way too many fried snakes and scorched nests, in addition to animals who suffered injuries from our fires.  It can be tough to deal with the knowledge that I made the decision to light the fires that killed or maimed those animals.

Regal
I’m sure we burned up a number of regal fritillaries in our fire last week because the females are within a few weeks of emerging as adults, and the kind of thatchy prairie we burned is prime habitat for overwintering larvae.  However, we would have done the same damage to those caterpillars if we’d burned the prairie any time between October and July.  Fortunately, regal fritillaries are very common in our prairies, so I know the overall population will be fine.

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garter
Snakes are common victims of growing season fires.  It’s likely we killed some snakes last week, though I didn’t see any corpses as I walked around the next day.  I did, however, find a live red-sided garter in one of the small unburned patches in the middle of the burn unit – so at least one survived…

While it can certainly be deadly to insects and animals, fire is also an important part of our strategies to maintain diverse and healthy prairie communities.  Fire can help suppress invasive species, remove thatch and stimulate vigorous plant growth, and attract grazing activity – among many other things.   Prairies that aren’t burned fairly frequently often suffer from tree/shrub encroachment, excessive build-up of litter, and/or dominance by a few native grass species.  Other tools, including grazing and haying, can be used instead of fire (or in addition to it) but those can also have negative impacts, and can’t replicate everything fire can do.  Knowing that fire can cause problems for some species, we try to minimize those impacts as much as we can.  For example, we usually only burn a portion of a larger prairie so that any impacts are not likely to affect the entire population of a species.

A smooth brome
Smooth brome was mostly done blooming when we burned, and starting to make seed.  I’m not sure how much we sapped the vigor out of the brome (a week or two earlier might have been better) but I guess we at least prevented it from making seed this year.

The main objective for our burn last week was to create an attractive patch of nutritious grass to concentrate cattle grazing in that portion of the prairie – part of our patch-burn grazing system.  We are using a light stocking rate of cattle this year, so we expect the grazing in the burned patch to be selective (the cattle should eat mostly grass) and to favor wildflower diversity by suppressing dominant grasses.  Meanwhile, unburned areas won’t be grazed much at all, allowing them to rest from previous years’ grazing and last year’s drought.  The result should be a messy mixture of habitat types and growing conditions across the prairie that will allow just about every species to thrive somewhere.

We’d hoped to burn the site earlier in the spring, but never got the right weather window to do it.  In other sites where we didn’t get our planned burns done this year, we’re using electric fence to temporarily enclose the cattle in what were supposed to be the burned patches.  The idea is to get the cattle to graze the areas down sufficiently that when we take the fence down in early July the cattle will continue to graze the regrowth (which will then be the best quality forage in the prairie) in those patches for the remainder of the season – similar to what we’d see in burned patches.  It’s far from a perfect subsitute for burning, but it does at least concentrate grazing pretty well in one portion of the prairie and allow other areas to rest.  The biggest disadvantage of the temporary grazing enclosure method is that cattle aren’t very selective in their grazing within that enclosure, so we lose some of the benefits we in burned patches when cattle graze mainly grasses.

patches of green
It was a pretty complete (though pretty slow and smoky) burn last week, but there were a few patches that didn’t burn – mostly in low, wet areas where the thatch was moist enough it didn’t carry fire.  The green strip shown here is at the bottom of a wetland swale and is also where I found the surviving red-sided garter snake mentioned earlier.

After weighing the pros and cons of burning in early June, we decided to go ahead with last week’s fire.  We certainly burned up nests of meadowlarks, grasshopper sparrows, and at least one turkey (a forlorn-looking female was wandering around after the fire).  I expect most of those will have time to re-nest, but that only makes me feel marginally better about it.  I’m sure we also killed lots of insects and some wildlife species.  On the other hand, the burn allows us to move ahead with our management strategy to improve the wildflower diversity of the entire prairie.  That increase in wildflower diversity will benefit a wide range of insect and wildlife species in coming years, as will the habitat structure created in both the burned and unburned patches.  We burned about 65 acres, but left more than 300 acres of the prairie unburned.  Actually, there is much more unburned prairie than that, since there are more than 1,000 acres of unburned grassland on adjacent land as well.  That unburned prairie should be a great refuge for fire-sensitive species and give them opportunities to recolonize last week’s burn over the next several years.

eastern red cedar
This eastern red cedar burned brown after the fire, but it’s unlikely to die.  Experience has shown us that growing season fires rarely “cook” cedar trees enough to kill them.  Even when they turn brown, they tend to green up again.  However, this prairie has had numerous dormant season fires, so cedar control was not an objective for last week’s fire.  We’ll get this one next time.

The kind of difficult decision we made last week is a regular part of land management.  Every management treatment leads to the improvement of conditions for some species but hurts others – often literally.  Just letting “nature take its course” by not managing at all isn’t any better.  An idled prairie eventually becomes dominated by trees and shrubs, along with just a few grass and wildflower species.  That degradation of habitat kills or evicts more animals and plants than active management, which maintains diverse plant and animal communities.

Right or wrong, I guess I’ve trained myself to focus on the long-term positive outcomes of our management and not to dwell on the short-term negative impacts.  I’m not sure if that makes me insensitive or just sensible.  One thing that helps me justify our actions to myself is that we’re collecting as much data as we can about the overall impacts of our management.  If we’re going to make tough decisions that have negative consequences for other living creatures, I want to KNOW that those decisions are leading to the long-term benefits we think they are.  We can never collect enough data to know everything we want to, but we collect enough that I’m convinced most of our management strategies are working as planned, and we constantly tweak those strategies as we learn more.

Ants
The ants in these mounds appeared to survive the fire just fine.  I assume they’ll be able to find plenty of food, and satisfy their other needs, as the prairie greens up around them over the next few weeks.

Regardless of the tough decisions we have to make, I love my job.  I feel good that we’re improving the condition of our prairies, and that we’re sharing successes and failures with other prairie managers so they can do the same.  It’s difficult for me to imagine a more fulfilling career.  I always try to focus on the big picture instead of dwelling on the immediate negative impacts of some of our actions.  At the same time, I try to be ethical about what we do, and not cause harm when it’s not necessary.

It’s a messy world and a messy job, but I wouldn’t have it any other way.

If You Play With Fire…

There’s nothing playful about safe and effective prescribed burning.  Too many things can go wrong to take it lightly.  Sometimes, I think people see prescribed fire as something that needs to be done to maintain prairies, but they can’t necessarily point to specific objectives for a particular fire.  Nor can they describe what kind of burning (season, intensity, size, ignition pattern) is needed to achieve those objectives.  Falling into the trap of burning because it seems like the right thing to do leads to two big risks.  First, there’s a good chance that the fires will not be conducted in a way (or at the right time of year) that do much good – and could even be counterproductive.  Second, because prescribed fire can be a hazardous activity, conducting one without clearly defined reasons means taking big risks for no good reason.

A prescribed fire we conducted last week. This one went off without a hitch. Most of them do.

We’ve completed two prescribed fires so far this spring.  As always, we spend way more time planning our fires than implementing them.  That planning starts with setting clear ecological objectives (defining why we’re burning in the first place) which dictate the location, size, season, and even the tactics used during the fire.  Once we know what we’re aiming for, we write a burn plan that can help us achieve that in the safest way possible.  Our plans detail the kinds of weather conditions and tactics needed to be successful, but also spend a lot of time on contingencies.  What will we do if the fire gets away?  What does the surrounding landscape offer in terms of safe areas and threats in the case of an escaped fire.  How will we respond if someone gets hurt?  For me, writing a good burn plan means thinking through all the worst case scenarios.  There’s nothing fun about it.

Unfortunately, even after all that planning, things still go wrong.  Last spring, I wrote about a burn we did in which we ran into repeated equipment issues, and had to shut down for a while until we could get re-equipped and complete the burn.  In another fire last year, I overestimated the strength of our blackline containing the fire, and the wind-driven head fire jumped it in one place, forcing us to quickly chase it down.  This spring, our first prescribed burn started out well, but the wind came up sooner than had been forecast, and we shut the fire down because a Red Flag Warning was issued.  In all of those cases, there were no serious repercussions, and our training and planning helped us deal effectively with unexpected circumstances.  Because we’d planned for each contingency, everyone knew how to react when the time came.  No property was damaged and no one got hurt.

The threat of injury is what makes prescribed fire especially stressful for me.  Between potential equipment mishaps and quickly-changing weather and fire conditions, there are numerous opportunities for someone to get hurt.  So far, I’ve never had anyone get injured on a fire I’ve been a part of, but that fortunate record certainly isn’t making me complacent.  As if I needed a reminder of the danger, one of our crew was helping a partner organization with a fire last week and suffered some slight burns on his neck and face while trying to extinguish a drip torch.  After trying and failing to smother the flame at the tip of the torch with a gloved hand (per protocol) the crew member then tried to blow the flame out, and some of the burning torch fuel splattered onto the cotton bandana around his neck.  Before he could get the bandana off of his head, he suffered small burns in several places.  After a quick trip to a nearby medical clinic, he was fine – though he had to shave off the remainder of his singed beard.

It appears there were several things that contributed to the torch incident, possibly including some issues with the torch itself that caused excessive fuel to build up in the torch’s tip, making it particularly difficult to extinguish.  After the fire was wrapped up there was considerable discussion about what happened, and hopefully we all learned some things that will make us all safer in the future.  Regardless of the cause, however, the aspect of the event that struck me the most was that our crew member was injured doing something he had done hundreds of times before.  It’s sobering to know that something as mundane as extinguishing a torch led to injury, and that it could have been much worse than it was.

Lighting the head fire of our prescribed burn last week. This was the easy part. The planning, training, weather monitoring, equipment preparation, and black-lining were all done. (Not pictured - the knot in my stomach)

I am a strong and vocal advocate for the use of prescribed fire to manage both private and public lands.  On the other hand, prescribed burning is not a sport, it’s a tool, and it’s a tool that we should employ strategically – not for fun, or without specific objectives in mind.  If someone can’t clearly explain what they’re trying to achieve by conducting a particular burn, I don’t know how they can justify taking the risk of dropping a match.  In addition, if some doesn’t have a clear and detailed plan for how to ignite and contain a fire, and how to respond when things go wrong, I don’t think they have any business lighting that fire in the first place. 

I know people that really enjoy conducting prescribed fires.  Frankly, those people make me nervous, especially if they’re in charge.  I don’t dislike prescribed burning, and I get a feeling of satisfaction whenever we wrap one up successfully – especially because I can appreciate the ecological benefits of doing so.  But while there is active fire on the ground, there’s a knot in my stomach, and that knot subsides slowly, even after the last of the smoke has faded into the sky. 

It’s fantastic that the use of prescribed fire is growing among prairie landowners and land managers.  More importantly, the greatly increased availability of training and equipment means that we’re not only burning more acres, but we’re also more sophisticated – and hopefully safer – as we do so.  However, things will still go wrong.  Property will be damaged and people will get hurt.  It can happen during even the simplest fires.  That doesn’t mean we shouldn’t burn.  It does, however, mean that we should burn only when it can be done safely and only when we can burn in ways that achieve important objectives.  Otherwise, the risk can quickly outweigh the rewards.

Be safe out there…

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You may be interested to read these previous posts about prescribed fire:

The importance of equipment redundancy in prescribed fire.

Why prescribed fire doesn’t contribute to global warming.

Reader Feedback Opportunity – What Do You Think?

I’ve been writing this blog for about eight months now, and it’s been an extremely enjoyable and fulfilling experience.  As I’ve told many people, I learn something from every post.  I learn by forcing myself to research, justify and corroborate my viewpoints and facts as I write about each subject.  I also learn from the many insightful comments and questions you’ve sent back to me through replies to posts, emails, and phone calls.

Stormy sky over a recently-burned Griffith Prairie, north of Aurora, Nebraska. Owned and managed by Prairie Plains Resource Institute, this diverse mixed-grass prairie has undergone extensive eastern red cedar removal and is managed with prescribed fire and grazing.

While writing the blog is fun for me, I’m doing it on work time – – so I have some responsibility to justify the time I spend on it.  It’s difficult to measure the effectiveness of something like a blog because although I get some statistics on how many times each post is read, I don’t really have any idea who’s reading it or what they think about it (except when people reply with comments/questions). 

I’ve decided that the most effective way to see whether or not the blog is achieving its objectives is to simply ask.  So – I’m asking. 

Here are my rough objectives for this blog:

1. Provide an interactive and updated source of prairie-related information as a companion to my book on prairie management.

2. Raise awareness and enthusiasm about prairies.

3. Provide a searchable on-line forum for discussion about challenges related to prairie management and restoration.

4. Improve the management and restoration of prairies by providing useful (and sometimes provocative) information and ideas.

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If you have a few minutes this week, I’d love to hear back from you about how I’m doing on those objectives.  You can simply reply to this post or you can send me an email (chelzer@tnc.org).  Please tell me what you think so far. 

–  Has the blog changed the way you think about or manage/restore prairies?

– Is the information technical enough?  Too technical?

– What do you like most/least about the blog?

– Do you have ideas for future blog post topics?  Any other suggestions for improving the blog?

I can’t thank you enough for reading (and responding to) the posts I’ve written so far.  I look forward to many more future discussions!