Our New Mechanical Seed Harvester

Seed harvest is a big part of our work here at the Platte River Prairies.  We don’t do as much complete restoration (converting cropland to high-diversity prairie) as we used to because we’ve just about run out of land to restore.  Instead we’ve shifted most of our seed work toward overseeding degraded remnant prairies that are missing many prominent wildflower species.  As a result, instead of harvesting from 230 plant species a year, we’re mainly focusing on getting as much seed as possible from about 30 to 40 species.

Nelson Winkel harvests Maximilian sunflower seeds by hand.

Nelson Winkel harvests Maximilian sunflower seeds by hand.

Most of our seed harvest is by hand, and when needed, we’ve been able to get adequate seed for up to 200 acres of cropland conversion work per year that way.  We’ve also used mechanical means to supplement our hand harvesting, including a couple different combines we’ve owned and pull-behind seed strippers we’ve borrowed from partners.  The mechanical harvesters have been helpful for getting big patches of seed from some grasses, sedges, and a few forbs.  However, the combines we’ve used aren’t very flexible about where they can go (hills and wet areas are tough) and the seed strippers’ brushes haven’t been aggressive enough to remove seed heads of some of the species we really wanted big quantities of – especially for our overseeding work.  However, a recent grant from the Nebraska Environmental Trust, via the Nebraska Game and Parks Commission, made it possible for us to purchase a new mechanical seed harvester.

Here, Nelson is harvesting grass seed with a mechanical seed stripper borrowed from Prairie Plains Resource Institute.

Here, Nelson is harvesting grass seed with a mechanical seed stripper borrowed from Prairie Plains Resource Institute.

After exploring a number of options, we decided to buy a seed stripper from Ned Groelz at Graywind Industries, Inc.  Our friends at Prairie Plains Resource Institute bought a pull-behind stripper built by Ned many years ago, and we liked a lot of its features – especially the ability to remotely control the harvester’s brush on the fly (turning it off and on and adjusting its height while driving through the prairie).  When we ordered our machine, we told Ned we were hoping to harvest large amounts of seed from plants with tough-to-remove seedheads and we weren’t sure a brush would be able to handle those.  He said he’d play with some ideas and see what he could do about that.

When Ned delivered the machine to us, he had a big grin on his face – a sure sign that he’d come up with something for our tough-to-harvest seed problem.  His solution was to replace the harvester’s brush with a more aggressive tool that included “stripping elements” – metal fingers, essentially –  made by the Shelbourne Reynolds company.  (Shelbourne Reynolds sells an attachment for combines that strips, rather than cuts, the grain from crops such as wheat and rice.)  Ned adapted their design for use in his pull-behind seed stripper and he was dying to know whether it would actually work.  Just to be safe, he designed the machine so that we could easily remove his experimental portion and replace it with a tried-and-true brush if we wanted to.

A close-up of the Shelbourne stripper elements included in Ned's new harvester design.

A close-up of the Shelbourne stripper elements included in Ned’s new harvester design.

Ned was so interested in testing his new design, he came out a couple weeks ago to watch it in action.  Without going into a lot of details, let me just say – it works great!  So far, we’ve tested it on wild bergamot (Monarda fistulosa), stiff sunflower (Helianthus pauciflorus), and Illinois bundleflower (Desmanthus illinoiensis), as well as a few others.

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Nelson and Ned watch the new stripper as it harvests seed from Illinois bundleflower.  The machine is offset from the UTV so the UTV doesn’t smash the vegetation down before it is harvested.

The stripper removes some stems and leaves, as well as seed pods, but leaves most of the plant behind.

The stripper removes some stems and leaves, as well as seed pods, but leaves most of each plant behind.

Ned and Nelson evaluate the performance of the new machine and talk about ideas for further improvements.

Ned and Nelson evaluate the performance of the new machine and talk about ideas for further improvements.

Hand-harvesting will still be an important component of our prairie restoration work. Many plant species are scattered here and there across a prairie and hand-harvesting is the only feasible way to obtain their seeds.  However, other plants occur in big patches, and this new machine is going to let us quickly harvest large quantities of seed from those, which will be a tremendous boon to our overseeding efforts.  We’ll need to do a little more seed processing (using hammermills and screens to separate seeds from the pods, stems, and leaves picked up by the stripper) than with hand-harvested seed, but that should go pretty quickly.

One of my favorite aspects of prairie restoration is the innovation displayed by people trying to come up with new effective ways to harvest seeds.  This new mechanical stripper is one more addition to a long list of those innovations.  Keep ‘em coming, folks!

For more information and pricing of Ned’s mechanical seed harvesters, contact him at:

Ned Groelz – Graywind Enterprises, Inc.

2927 W 700 S
Syracuse, UT 84075-9764
Mobile: 801-803-0412
E-mail ngroelz@gmail.com

I want to be perfectly clear -this post was not sponsored by Graywind Enterprises, and we paid full price for the seed stripper and its components.   All the opinions about this equipment and how it worked are just my opinions.  My intent is to let others know of the existence of this machine in case it can help move prairie restoration and conservation work forward.

 

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Photo of the Week – September 18, 2014

I’m writing this from The Nature Conservancy’s Niobrara Valley Preserve in north-central Nebraska, where I’m attending a prescribed fire planning workshop.  The weather up here is beautiful, and the prairies are already wearing their autumn colors.  The most conspicuous color on the landscape is the bright red of smooth sumac, which contrasts wonderfully with the more subtle browns and golds of the grasses.

Smooth sumac and prairie along the Niobrara River at The Nature Conservancy's Niobrara Valley Preserve.

Smooth sumac and prairie along the Niobrara River at The Nature Conservancy’s Niobrara Valley Preserve.

This photo was taken in one of the few parts of the Preserve that wasn’t impacted by the big wildfire of 2012.  I walked and photographed areas that were affected by the fire as well, and I’ll post some of those photos and descriptions soon.  In short, everything I saw is looking great; no significant invasive plant issues, complete recovery of grasslands, and positive developments under the burned pine woodland areas.

 

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Konza Prairie Trip Part 3 – Questions About Frequent Prairie Burning

A few weeks ago, I wrote about our trip to the Konza Prairie Biological Station in eastern Kansas.  On that trip, we learned about research results showing that frequent spring fires (one or two year frequency) can prevent encroachment of tallgrass prairie by trees and shrubs.  Less frequent fire allows shrubs, especially dogwood and sumac, to invade.  Pretty simple – we should be burning tallgrass prairie at least every two years, right?

Hang on just a minute, Sparky.

As you might expect, there is more to the story.  It turns out that the frequent spring fire (with no grazing) regimes at Konza has other impacts.  One example is that frequent fire favors grasses over forbs and decreases plant diversity over time.  Prairies that are burned every year or ever two years develop a grass-dominated plant community in which many forb species are difficult to find.  So, frequent fire is bad for plant communities…  Right?

Annually-burned tallgrass prairie at Konza Prairie, in the Flint Hills of eastern Kansas.

Annually-burned tallgrass prairie at Konza Prairie, in the Flint Hills of eastern Kansas.  August 2014.

But in other tallgrass prairies, especially in more eastern prairies such as those in Illinois, researchers are seeing very different impacts of frequent fire.  A paper by Marlin Bowles and Michael Jones, for example, found that frequent fire “stabilizes” plant communities in the Chicago, Illinois area, and that plant diversity was positively correlated with fire frequency.  In fact, their results are almost the exact opposite of what was seen at Konza.  In the Illinois study, frequent fire decreased the dominance of warm-season grasses and increased the diversity of summer wildflowers.

Frequently-burned prairie at the University of Wisconsin-Madison Arboretum.  Clearly, frequent fire is not incompatible with plant diversity...

Frequently-burned prairie at the University of Wisconsin-Madison Arboretum. Clearly, frequent fire is not incompatible with plant diversity…

What the heck is going on??

If we could answer that question, we’d be miles ahead of where we are now in terms of understanding prairie ecology.  I can come up with lots of potential reasons for the difference between frequent fire application in Illinois versus Kansas, but I can’t confirm or deny any of them – we simply don’t know.  As I think about why prairie plant communities might become more dominated by grasses over time, I wonder about factors such as small scale plant diversity, soil productivity, and the soil microbe community – all of which may correlated with each other.

Eastern remnant (unplowed) prairies tend to have a higher density of plant species (e.g., plant species per square meter) than western prairies. High species density could potentially help suppress grass dominance because of the variety of competition strategies each of those plant species employs to take and defend territory.  Those strategies include allelopathy (releasing chemicals that retard growth of nearby plants), rhizomes (underground stems that can connect even fairly distant stems of the same plant together), root density/depth, and many others.  It seems logical that communities with that kind of well-established complex competitive environment would present a major challenge for any species (grasses or otherwise) trying to become dominant.  Maintaining consistent growing conditions by burning or haying annually might facilitate stability within those plant communities because it essentially maintains a stalemate; no plant species is ever given a window of opportunity to gain advantage over its neighbors.  Or this could all be balderdash – I’m just throwing out ideas here.

Does the rich soil organic matter content of eastern tallgrass prairies help suppress grass dominance?  It’s probably the major reason for the higher plant species density in those prairies, so maybe.  On the other hand, research at Konza and elsewhere in more western prairies shows that adding nitrogen to prairies (increasing productivity) increases grass dominance and lowers plant diversity.  Hmm.

Soil microbial communities surely have a very important influence on plant diversity, but (as discussed in a previous post) we don’t know much about them yet.  I’m optimistic that our understanding of soil microbes will grow tremendously during the next few decades, but the complexity of that world might mean that it will take many more decades before we start to get a grasp on it.  In the meantime, we can use it as a convenient scapegoat.  If something you don’t like is happening to your prairie, it’s probably a soil microbe problem…

Those of you who read this blog frequently may be surprised that I haven’t mentioned insects or other animals yet.  Let’s talk about them now, shall we?

It’s very important to remember that even if frequent burning seems to maintain high plant diversity in (some) prairies, a prairie is much more than just plants.  The use of frequent fire tends to create fairly homogenous habitat conditions across a prairie.  Regrowth rates are similar across the whole burned area, so vegetation height and density is relatively uniform.  Dead material, including both litter and standing dead vegetation, is scarce.  Because habitat diversity is limited, so is the diversity of creatures that rely on that habitat.  In taxonomic groups ranging from grasshoppers and spiders to mice and birds, research shows that habitat diversity is positively correlated with species diversity.  Creating habitat heterogeneity – through grazing, patchy mowing, or other means can help facilitate a more diverse animal community.  Burning in a less regimented way can help too, especially if that means splitting a prairie into multiple management units and burning only a subset of those each year.

Habitat

Heterogeneous habitat structure, including tall, short, and mixed-height vegetation – like that shown here – can help maintain diverse invertebrate and wildlife communities.  Grazing is one great way to manipulate vegetation structure, but isn’t feasible at all sites.  Grazed prairie at The Nature Conservancy’s Platte River Prairies, Nebraska.

In small isolated prairies, it’s also critically important not to burn (or mow) the entire prairie at the same time.  With limited opportunities for species to recolonize from other prairies, a fire that kills all of the individuals of a particular species (e.g., an insect that overwinters in the stems of grasses or in the litter along the ground) can mean the end of that species’ existence in that prairie.  Maintaining a floristically diverse prairie without a full complement of invertebrates doesn’t seem like success to me.  On the other hand, I also appreciate the difficulties associated with managing small prairies.

To wrap this up, I think there are two really important points to make about fire frequency in prairie management.  First, there are some big questions about why frequent fire seems to maintain high plant diversity in some prairies but encourages grass dominance in others.  Figuring out the answers to those questions may be one of the more important keys to prairie conservation success.  Second, even if frequent fire maintains high plant diversity and repels invasion by shrubs and trees, it still might not be the best choice for a prairie management strategy.  There is much more to a prairie than its plants, and even if you don’t much care for invertebrates, birds, reptiles, or mammals (and how could you not?) those species – especially the invertebrates – are strongly tied to the long-term viability of the plant community, so it’s probably not good to ignore them.  To be clear, I’m not saying people who use frequent fire are evil destroyers of animals.  I’m just raising a flag of caution and pointing out some potential tradeoffs.

Prescribed burning is an important management tool, but its impacts on prairie communities can be complicated.

Prescribed burning is a valuable management tool, but its impacts on prairie communities can be complicated.  It’s important for prairie managers to recognize and account for both the negative and positive impacts of fire.

Those of us who work with prairies are used to the seemingly overwhelming complexity of grassland communities and the way those communities respond to management.  In fact, for many of us, it’s a big reason we love prairies as much as we do.  While we still have more questions than answers about effective prairie management, we have enough information to go forward with.  Most importantly, prairies are pretty tough, so excepting drastic measures such as broadcast spraying with 2,4-D (and maybe burning an entire tiny prairie), we have the latitude to try out lots of ideas and see what works.  We’ll learn as we go.

In the meantime, it’d be great if all you researchers out there would get cracking on the issue of disparate effects of frequent fire in eastern versus western prairies.  It should only take a few decades to figure it out…  Right?

 

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Photo of the Week – September 12, 2014

It’s grasshopper season!

Vehicles driving through the prairie on a late summer morning are quickly covered with dew, grass pollen, and GRASSHOPPERS.

Vehicles driving through the prairie on a late summer morning are quickly covered with dew, grass pollen, and GRASSHOPPERS.

By the end of summer, most grasshoppers have completed their five or so molts and have become adults – complete with functional wings.   Now, as we walk and drive through our prairies, these fully-formed adult grasshoppers (along with katydids and tree crickets) seem to be everywhere.  They explode from our feet like popcorn – especially in areas of shorter vegetation.  And they’re hungry.  We see them feeding on sunflowers, goldenrod, grasses and almost every other kind of plant in the prairie.  As in other groups of species, the diversity of grasshopper species (108 species in Nebraska) leads to a diversity of feeding habits.  Some feed high in the canopy, others low.  Some feed mainly on grasses, others on forbs.  Some eat from a wide range of species, others from just a few.

This grasshopper was feeding on the pollen of stiff sunflower - an apparent favorite of many adult grasshopper, katydid, and tree cricket species.

This grasshopper was feeding on the pollen of stiff sunflower (Helianthus pauciflorus) – an apparent favorite of many adult grasshopper, katydid, and tree cricket species.

Another grasshopper species (probably) also feeding on stiff sunflower.

Another grasshopper species (probably) – also feeding on stiff sunflower.

Tree crickets get in on the stiff sunflower pollen feeding frenzy too.

Tree crickets get in on the stiff sunflower pollen feeding frenzy too.

Predators, of course, respond enthusiastically to the profusion of grasshoppers.  Rather than taking over the world, late summer grasshoppers become the targets of any creature that can catch up with them.  This includes birds, mammals, reptiles, and large invertebrate predators, but also tiny parasites and microbes.  To hungry predators, grasshoppers are just tasty machines that convert vegetation into protein-rich food – and they’re EVERYWHERE!

'Hoppers and their kin, but they can also be skilled at keeping themselves hidden when they see a potential predator.  This katydid didn't like me sticking my camera lens in its direction.

‘Hoppers and their kin, but they can also be skilled at keeping themselves hidden when they see a potential predator. This katydid didn’t like me sticking my camera lens in its direction.

The prairie is also a noisy place when grasshoppers, katydids, and tree crickets reach adulthood.  Much of the communication between these species is through sound, and it can be hard to hear the rustling of autumn prairie leaves in the wind over the buzzes and whines of insect courtship.

Besides leading females to males, that incessant insect noise acts as a warning to herbivore and predator alike…

“You’d better eat up now – winter is coming!”

 

Posted in Prairie Insects, Prairie Natural History, Prairie Photography | Tagged , , , , , , , | 8 Comments

Using a Tree as a Giant Diffuser for Macro Photography

I want to start by acknowledging the irony in this post.  As someone who has spent a lot of time killing trees in prairies and urging others to do the same, it’s pretty funny that this post is all about the positive aspects of having a big tree in a prairie wetland.  In my defense, I’ve never said there shouldn’t be ANY trees in prairies, and I’m writing this particular post as a photographer, not an ecologist.  Matt H and other tree lovers – this one’s for you. 

I was out on the edge of one of our restored wetlands last week as the sun was coming up.  The wind was calm, the weather was cool, and I was hoping for some nice close-up photos of flowers and insects.  Most photographers know that first light is a great time for photography because the sunlight is soft and warm as the sun pops over the horizon.  Often, a little haze or thin cloud cover near the horizon can extend that period of nice diffused light as the sun rises higher.  Last week, however, there was no haze or cloud cover to help out, and I only had about 10 minutes between the time the sun breached the horizon and the point at which the light was too bright to make good photos.

Fortunately, (I can’t believe I’m saying this) there was a big cottonwood tree nearby and I had the opportunity to use a little trick I’ve found useful for extending my time window for close-up photography.  Essentially, I just followed the shadow of the tree as the sun rose into the sky.  I didn’t take pictures in the shade, exactly, but neither did I take pictures in the sun.  I used the very edge of the shadow.

Here's my elegant diagram of how to use the diffused light found right at the edge of the shadow of a tree in the first hour or so after sunrise.  I find a composition near the edge of the tree's shadow and then wait until the light just starts to pop through the top of the tree's leaves to snap the shutter.

Here’s my elegant diagram of how to use the diffused light at edge of a tree’s shadow during the first hour or so after sunrise.  As the sun rises, the tree’s shadow shortens, but in the soft edge of the shadow, the light is beautifully diffused and perfect for close-up photos.  I find a composition just inside the edge of the tree’s shadow and then wait to snap the shutter until the rising sun’s light just starts to pop through the upper leaves of the tree.  Then I move closer to the tree, find another subject, and start the process again.

The boundary of the shadow created by a big tree is not a hard edge.  Instead, there is a narrow zone of diffused light between complete shade and bright sunlight.  That narrow zone creates some nice opportunities for photography.  Essentially, I just follow the shadow as it moves across the ground.  I find potential photo compositions inside the shadow and then take the picture as the edge of the shadow passes by.  I have to work quickly because the shadow moves right along, but I usually have enough time to get several shots of each subject in nice light.

Here are some photos from from last week’s tree-diffused light.

I had time to take 4 or 5 quick shots of this great lobelia (Lobelia siphilitica) before the shadow moved away completely and the light got too bright.  The Nature Conservancy's Platte River Prairies, Nebraska.

I had time to take 4 or 5 quick shots of this great lobelia (Lobelia siphilitica) before the shadow moved away completely and the light got too bright. The Nature Conservancy’s Platte River Prairies, Nebraska.

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Several species of beggarticks (Bidens) grow along the edge of wetlands along the Platte River.

Several species of beggarticks (Bidens) grow along the edge of wetlands along the Platte River.

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Field mint (Mentha arvensis) is another wetland edge plant.  Plants in the mint family usually have a pronounced square stem.

Field mint (Mentha arvensis) is another wetland edge plant. Plants in the mint family usually have a pronounced square stem.

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This damselfly was the only one I successfully photographed - out of more than a dozen I stalked.  I crept slowly up to it with my tripod while it was still in the shade of the tree and then got my photo as the shadow's edge came across it.

This damselfly was the only one I successfully photographed – out of more than a dozen I stalked. I crept slowly up to it with my tripod while it was still in the shade of the tree and then got my photo as the shadow’s edge came across it.

Interestingly, our staff has had several discussions over the years about whether or not we should cut down the big cottonwood I used as a photo diffuser last week.  There are some good ecological arguments for taking it out.  For example, large trees act as perches for predatory birds and can affect the way other birds use nearby habitat.  Migratory sandhill cranes (a focus of our wetland management) tend not to roost near trees, and many breeding bird species avoid nesting near them as well.  In addition, trees often act as gateways for invasive plants because they create a different microclimate that favors some invasives (especially cool-season grasses) and because they attract perching birds that drop seeds of other invasives.

Good ecological arguments can be made for keeping the tree too – including some that are similar to the arguments against it.  It’s kind of nice to have a big tree for eagles and other large predatory birds to hang around in because predators are important players in the ecosystem.  Orioles, red-headed woodpeckers, kestrels, and many other bird species – including some of conservation concern – nest in big cottonwoods.  Also, the plants that grow beneath cottonwoods are not all invasives, and include some nice native species such as Jerusalem artichoke, Virginia wild rye, and many others.

To be honest, the biggest factor that has swayed our discussions about the tree is its size.  No one has really felt like tackling the job of cutting it down, so the arguments to keep it have gained the upper hand.

I guess that’ll be ok…

 

Posted in Prairie Photography | Tagged , , , , , | 10 Comments

Photo of the Week – September 4, 2014

It’s not often the wind is calm enough to get a good sharp photo of a spider in its web, but everything came together nicely late last week as I walked around one of our restored wetlands.  There were a number of long-jawed orbweaver spiders (Tetragnathidae) in their webs, but this one was the most accomodating…

A long-jawed orbweaver in early morning light.  The Nature Conservancy's Platte River Prairies, Nebraska.

A long-jawed orbweaver in early morning light. The Nature Conservancy’s Platte River Prairies, Nebraska.

Of course, I missed a great shot of a nearby spider that had caught a mosquito.  The light was great, the composition was going to be fantastic, but my tripod leg bumped the grass stem holding the web and the spider hightailed it to safety.  Oh well.  I still got to see and enjoy it – I just can’t share it with you.

 

Posted in Prairie Insects, Prairie Natural History, Prairie Photography | Tagged , , , , , , , , , | 3 Comments

Konza Prairie Trip Part 2 – Tree and Shrub Encroachment

A couple years ago, I wrote about some work from Kansas State University related to woody plant expansion in prairies.  Many of us who work with prairies constantly wrestle with questions about trees in prairies. Why are they encroaching so quickly these days? What prevented them from doing that in the past?  During our recent trip to Konza Prairie, we got to discuss this topic more in-depth with Jesse Nippert and other researchers at Kansas State.

Clearly, a combination of factors influences how quickly trees and shrubs enter and spread in grasslands.  One big reason is the increase in “seed rain” in some of today’s prairies.  Prairies in fragmented landscapes with numerous trees and shrubs in nearby woodlots, road ditches, shelterbelts, etc., are deluged with seeds from those woody plants.  The vast majority of those seeds fail to establish, but the high number of seeds coming in means that some will find opportunities to grow.

Smooth sumac clones like this small one are expanding at Konza Prairie, especially in areas burned less frequently than every other year.

Smooth sumac clones like this small one are expanding at Konza Prairie and many other sites in central North America.

Other factors may include the higher rates of carbon dioxide in today’s atmosphere and higher amounts of nitrogen deposition (from industry and agricultural facilities, for example), both of which tend to favor woody plant establishment.  In addition, we are in a relatively wet climatic period if you look at the geologic record.  While there have been droughts, including severe ones, in recent years, those droughts are nothing like the multi-decade severe droughts that can be seen in the relatively recent geologic records for the central United States.  Long and/or frequent droughts favor herbaceous plants (such as grasses and wildflowers) over trees.

However, Jesse Nippert’s research into the way trees, shrubs, grasses, and forbs (wildflowers) compete for water belowground provides some additional insight into the march of woody plants into prairies.  As we started talking about roots, Jesse confirmed something I’d heard from Dave Wedin at the University of Nebraska; even though grasses can have very deep roots, most of their water use is actually very shallow – within the top 25 cm of soil.  Jesse says the reason those grasses persist during very dry periods is not because of their deep root systems, but because they can continue to grow and function when available soil moisture is very low.  Forbs also pull a lot of their moisture from shallow roots, but utilize slightly deeper roots (50-75 cm deep) during droughts because they can’t compete well with the ultra-efficient fine-rooted grasses at the upper levels.

It turns out that understanding root competition might help us better understand woody plant encroachment as well.  In many parts of Konza prairie, clonal shrubs such as rough-leaved dogwood and smooth sumac have expanded rapidly over the last several decades.  As Jesse and his students have studied this phenomenon, they have concluded that an important factor behind this expansion is the strategy those shrub clones use to acquire water.  While grasses and forbs are mostly using water from the top 1/2m of the soil, shrubs pull much of their water from deeper in the soil profile, allowing them critical access to water not being utilized by their competition – especially in years when the upper soil layers are dry.

The clonal form of dogwood and sumac gives them another advantage.  As clones expand, the tillers (aboveground stems) on the outer edge of the clones have very small roots.  However, by studying the isotopic signatures of the water in those shallow-rooted tillers, Jesse can tell that they are also accessing water from deep in the soil profile.  He says this is almost surely because the older, deep-rooted plants in the center of the clone are sharing the water they acquire with the younger stems on the outside.  Not a bad strategy.

Of course, as these clones of dogwood and sumac use their water acquisition and sharing strategy to advantage and spread into the prairie, they also shade out their competition – especially beneath the tall/dense tillers toward the centers of clones.  Suppressing the growth of grassy undergrowth not only removes that competition for resources, it also helps make the clones fireproof.  Since dried grasses are the primary fuel for prairie fires, the absence of grasses beneath shrub clones means that fires can’t burn through them.  It’s not hard to see how the processes of deep water acquisition/sharing and fire-proofing can create a positive feedback loop that helps drive an inexorable expansion of shrubs into the surrounding prairie.

We didn’t talk about this in Kansas, but my experience is that fire-proof shrub clones are an important avenue for the establishment of trees as well.  Many tree seeds are deposited into those shrub patches by birds that see those shrubs as convenient and prominent perching sites.  If those seeds are able to germinate and establish within those clones – and they often can – the resulting trees can grow without fear of the fires that would otherwise threaten them.  Hiding in the middle of big shrub clones also gives those trees a chance to grow in relative safety from marauding prairie land managers…

Because much of Konza prairie has been managed under a variety of long-term fire regimes (1,2,4,10, and 20 year frequencies), Kansas State Researchers have some pretty good data on how fire frequency affects shrub expansion as well.  Essentially, prairies burned every year or every other year do not have encroachment by dogwood or sumac, but prairies burned less often are being gradually overtaken by shrubs.  Interestingly, the fastest expansion appears to be in prairie watersheds managed with a fire frequency of every four years (which is also about what the estimated average fire frequency was for that landscape during pre-European settlement).  While it might seem counterintuitive that a four year fire frequency allows for faster woody encroachment than a 10 or 20 year frequency, the explanation appears to lie in the way shrubs respond to fire.  Fire seems to stimulate radial growth in dogwood and sumac, meaning that the plants put an emphasis in growing horizontally rather than just vertically after they are burned.  Under very frequent fire, this is apparently immaterial, probably because the shrubs never get enough rest between fires to take advantage of that radial growth.  However, when they are given 3 years to recover between fires, that radial growth response after each fire means that burning actually stimulates faster expansion of shrub clones.  Under a 10 year fire frequency, that extra radial growth only occurs once every 10 years, so the overall expansion is actually slower than in under a four year fire regime.

Small research plots like these at Konza Prairie help demonstrate the impacts of various fire frequencies.  The treeless grassland to the left is burned annually.  The wooded area to the right is burned every 20 years.  Both started out looking the same.

Small research plots like these at Konza Prairie help demonstrate the impacts of various fire frequencies. The treeless grassland to the left is burned annually. The wooded area to the right is burned every 20 years. Both started out looking the same.

Before you jump to the conclusion that burning every year or two seems the obvious best strategy for shrub control, remember that woody plant suppression is only one of many objectives for prairie management.  I’ll address some of the other, less positive, effects of frequent fires at Konza in an upcoming post.

As I said earlier, there are multiple factors that affect the rate of tree and shrub encroachment on prairies.  Seed rain might be as important as anything, and climatic conditions, increases in nitrogen and carbon dioxide levels, and fire suppression are all likely contributors as well.  However, the way plants compete belowground, particularly the deep water use strategy of clonal shrubs such as dogwood and sumac, also seems to play an important role.   Frequent fire application can be one way to prevent encroachment, though it comes with other baggage (see upcoming post…) and may not help remove shrub patches once they’re established.  At Konza, they took some of the every-20-year-fire-freuency watersheds and started burning them annually to see if they could get rid of the shrubs and trees.  Thirteen years later, those patches are still there, though the individual stems are much smaller.  It seems that while frequent fire might help prevent woody plant establishment, frequent fire alone might not be able to reverse it – at least not on a very fast timeline.

Woody plant encroachment is one of the biggest challenges we face in prairie management today.  A solid understanding of the mechanisms behind that encroachment should help us design more effective strategies to combat it.  Shredding, burning and herbicide application are all useful tactics, but figuring out the timing, frequency, and intensity of those applications will be critical.  We need to use the various competitive strategies of grasses, forbs, and shrubs to our advantage.  As an example, some recent work by Dirac Twidwell (University of Nebraska-Lincoln) seems to indicate that burning under more extreme heat and drought conditions than we typically feel comfortable with might be one way to really tip the scales away from woody plants.  The feasibility of that will be limited in some landscapes, but surely there are other innovative tactics that can help.  If we work together and aren’t afraid to try some new ideas, we can figure this out.

 

Posted in Prairie Management, Prairie Natural History, Prairie Plants | Tagged , , , , , , , , , , , , , , , , | 33 Comments

The Hidden Depths of Kim Tri

When Kim Tri (pronounced “tree) contacted us about coming out to volunteer for a month in the late spring/early summer, we weren’t sure what to think.  Why would someone from Sterling College in Vermont – a tiny little liberal arts school we’d never heard of – want to come spend a month learning about prairies and doing land stewardship work?  She said she needed to do a senior project for school which would entail keeping a journal while she was here and then producing a mural (?!) as a final product.  Hmm…

However, as we looked into her a little more, we felt a little more comfortable.  She had grown up in Rochester, Minnesota and had spent a couple years doing Conservation Corps work around the country, so she at least had some familiarity with prairies and hard work.  Plus, we weren’t in a position to be too picky – we really needed the help.  …We got back to her and said we’d be happy to host her for a month.

When Kim arrived, we were in the midst of an herbicide spraying campaign against both musk thistles and poison hemlock.  She jumped right into the fray, joined the crew, and was a huge help.  Besides being a quick study and hard worker, we also learned that Kim was an artist of considerable skill.  She showed us some of her sketches and paintings one afternoon, and it was clear she knew what she was doing.   The mural idea started to make a little more sense, though I was really curious to see what she would come up with.  Before Kim left us, I asked her to send me a photo of the mural when she finished it, and said that maybe between some of her journal writing and the mural, we could make a blog post of some kind about her experience.  (I kept my expectations fairly low.)

Kim at the Niobrara Valley Preserve during a rare moment of leisure.

Kim at the Niobrara Valley Preserve during a rare moment of leisure.

Last week, Kim sent me a photo of the mural (see below) along with a complete – and excellent -blog post, already written and ready to go.  She even had some very nice photos to illustrate the post.  I think you’ll appreciate her talents as you read her essay and enjoy her photographs and mural.  I’m going to get out of the way now and let you do that.

All the writing and artwork below are by Kim.

            The announcement that I had plans in Nebraska was treated with a sort of pitying disbelief, expressed in one word.  “Why?” I brushed this off, steering more than one of these conversations around with an inspiration drawn from the cause for which I was prepared to travel a thousand miles and back.

            Earlier this year, my answer to a similar question was much different.  I recall mentioning the idea of spending time in Nebraska or Kansas.  That time had to be spent somewhere with prairies and the folks who conserve them, according to the proposal I’d written for my senior project.  Why Nebraska or Kansas?  “Because I hate them so much,” I’d laugh.

            Let me first say that I didn’t really mean that.  Every state has its charms.  The real reason, which I was reluctant to articulate, was to challenge myself.  It was crucial, personally, to prove that prairies were as dear to me as I felt they were when I was rambling around the Green Mountains.  Would I feel the same in the midst of a state for which I held no affection?

            Really, I only personally disliked Kansas.  For me, Kansas was long, flat hours in the long, flat dark, a long, long way from anywhere called home.

            Nebraska, in my only experience of the state, was a snowstorm following me from Arizona.  It was blurry stretches of highways that had to be travelled in order to make it back to Minnesota.  Also, I remember red noses stuck on the deer crossing signs, but that’s beside the point.

            My attitude towards Nebraska came from a friend who had logged a lot of hours travelling through the state and was convinced that the country would be better off without it.  This friend visited me at the Platte River Prairies on his way across the interstate.  One spectacular sunset and an evening in the Sandhills later, he turned to me where we sat on the shag carpet of the legendary Derr House.  “So this is school for you?” he said.  “I guess you’ve got it figured out.”

            Yup, I’d say so.

Blooming prickly pear cactus along the Platte River in Nebraska.  Photo by Kim Tri.

Blooming prickly pear cactus along the Platte River in Nebraska. Photo by Kim Tri.

            Before arriving at the Platte River Prairies, the place for me was mostly a blank.  Having briefly looked over this blog while studying, I half-remembered having seen the preserve through the lens of another’s camera, but all I really had was a dot on a map.  Of all of the handy volunteer pages for the various Plains states on The Nature Conservancy website, theirs was the best put together.  It offered housing to scholarly volunteers who were interested in a month or so of work.  Decision made.

            I blew into the preserve on the harsh wind of a Plains thunderstorm, which gave way to a long, rainy day in which to think about what I’d done.  I had no apprehensions about the house, but still I felt the niggling doubt that accompanies me on every move.  Where the heck was I?  Marooned in a vast island of corn, so different from the mountains of the past few years.  Also, it was rainy.

            Still, I had to explore—meet the neighbors, so to speak.  I first became acquainted with the little prickly pear in the yard, a reassuring sign of being back west.  Then I met the yellow spring flowers, the ragwort and puccoon—sunny faces on a gray day, particularly when the sun shone on them through the breaks in the clouds.  The sudden sunlight also illuminated the grazing cows, making them appear touched with grace.  The cattle were also neighbors, which I came to accept despite my lifelong dislike of cattle.  They are essential parts of the natural community in a grassland ecosystem evolved to grazing.

Prairie ragwort (Packera plattensis) - The Nature Conservancy's Platte River Prairies.  Photo by Kim Tri

Prairie ragwort (Packera plattensis) – The Nature Conservancy’s Platte River Prairies. Photo by Kim Tri

Cattle grazing along one of the hiking trails through the Platte River Prairies.  Photo by Kim Tri.

Cattle grazing along one of the hiking trails through the Platte River Prairies. Photo by Kim Tri.

           My doubt didn’t last long.  This vibrant little community of the prairie bustled with inhabitants.  Kingbirds flicked their tails, deer bounded away, hawks soared, owls called, waterfowl preened.  Insects buzzed and greeted the new blossoms.  I, too, greeted the opening flowers, alert for something new every day to write in the journal which I was tasked to keep of my time in Nebraska.  Now, as much as I appreciate Aldo Leopold, phenology had always seemed tedious.  Then, suddenly, I understood.  I was elated at the sight of the first blooming prairie coneflower.  Ever since learning to recognize it, I’d been eyeing its developing buds and waiting.

Yellow coneflower, aka upright prairie coneflower (Ratibida columnifera).  Photo by Kim Tri

Yellow coneflower, aka upright prairie coneflower (Ratibida columnifera). Photo by Kim Tri

            What I remember most is a sense of peace in the tall grass.  Back in Vermont, there was no end of inspiring landscapes, but the trees and hills were becoming stifling, making me restless.  Out on the prairie, it was different.  Studying the grasslands was not like studying the forests, in a way that’s difficult to describe.  Perhaps it’s the clarity of being able to see so far.  Perhaps it’s watching the mood of the sky for warning weather, the wild power of the thunderstorms that make all calm days seem extraordinarily tranquil.

            There was something also in my timing that seemed perfect, as well.  In my brief spell at the preserve, I got to experience the last burn of the season, straggling Sandhill cranes, the Niobrara preserve and their legendary bison tours, an unusually early Field Day, and a succession of wildflowers.

Colorful clouds over the prairie before sunrise.  Platte River Prairies. Photo by Kim Tri.

Colorful clouds over the prairie before sunrise. Platte River Prairies. Photo by Kim Tri.

            Perhaps it’s always the right time to be at the Platte River Prairies.  That would explain the chronic volunteers, who indulge their prairie work like a habit, and the revolving door of visiting researchers.  And everyone had something to teach, more than I could readily absorb.  Back in Vermont, a stack of books and an unreliable internet connection were my portal into the prairies.  Being in Nebraska, I was surrounded by dedicated and knowledgeable folks, and was frankly a little spoiled.  I’d gone from teaching my senior project advisor about drought and fire ecology to living it, being schooled by others and the land.

            In a long line of good life decisions, I can add this one to the list, for sure.

Mural by Kim Tri, inspired by her time in The Nature Conservancy's Platte River Prairies, Nebraska.

Mural by Kim Tri, inspired by her time in The Nature Conservancy’s Platte River Prairies, Nebraska.  Please click on the image to see a larger, sharper version.  It’s worth it.

 

Posted in General, Prairie Photography | Tagged , , , , , , , , | 14 Comments

Photo of the Week – August 28, 2014

I made a quick run out to our family prairie this week to see how our grazing management was looking.  It was a beautiful evening for a stroll, as the sun went down through layers of diffuse clouds.  The abundant rain this year has fueled tremendous growth in the prairie and has filled up the wetland to its rim.  As planned, a portion of the prairie is short-cropped by cattle grazing while other areas are either ungrazed or lightly grazed, and there was a lot of life on display.

Grasshoppers and katydids exploded around my feet as I walked around – most of them clearly adults since they were flying short distances before landing again (they only get wings after their final molt into adulthood).  They were joined by hordes of other invertebrates, including caterpillars, bees, butterflies, and many others.  I flushed a great horned owl from a big ash tree, and then was very pleased to see a rail (probably a Virginia rail) dangle its feet as it flew across our recovering wetland.  Here are a few photos from the night.

Caterpillar

I’ve seen this same species of caterpillar in a couple places this week.  This one was munching on false boneset.

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Dotted gayfeather and stiff goldenrod were both abundant upslope of the wetland.

Dotted gayfeather and stiff goldenrod were both abundant uphill from the wetland.

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A close-up view of dotted gayfeather.

A close-up view of dotted gayfeather.

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Our wetland at sunset.

Our wetland at sunset.  The addition of a couple solar-powered wells for livestock water has allowed us to exclude cattle from the pond/wetland area, and the habitat improvements are obvious.

A quick note of thanks:  This blog quietly passed two milestones this week.  I posted my 500th post, and we passed the 1,800 mark on blog subscribers.  Thank you for your continued support of this site – I hope it’s as useful and enjoyable to you as it is to me.

Posted in Prairie Natural History, Prairie Photography | Tagged , , , , , , , , , | 12 Comments

Field Day Reminder – TOMORROW, Rain or Shine! Also, A Bee Photo

A reminder – we will have our Platte River Prairies Field Day tomorrow, August 27, from 9am to 3:30.  Details can be found here.

Rain is in the forecast for tomorrow, but it looks like the best chances for precipitation are before and after the Field Day.  Either way, we’ll be there and will have plenty of things to see, do, and discuss, so please plan to attend.  (However, in addition to your lunch, you might throw in a rain jacket and/or umbrella just in case.)

Now that we’ve got that out of the way, here’s something completely unrelated:

As I was walking across my yard on the way home from work last night, I saw the following happening RIGHT IN THE MIDDLE OF MY SIDEWALK.

Two bumblebees (Bombus impatiens) trying to ensure the next generation of bumblebees.

Two bumblebees (Bombus impatiens) trying to ensure the next generation of bumblebees.

Three things.  First, this is a good way to see the sexual dimorphism of bumblebees.  (Don’t get excited – it just means that males and females are different sizes.)  Second, the stinger on the female looks like it’s in an awkward place.  Finally, the process of making new bumblebees apparently takes a while and the full attention of both parties.  I had time to go back to the truck, grab my camera gear, set up a couple flashes, and take quite a few photos.  After I got my photos, I put my gear away and walked by again and they were still going.

During the whole photography process, the bees completely ignored me, my gear, and the repeated firing of two flash units.  It seems like the bees would be pretty easy quarry for predators at times like this.  Maybe, instead of doing it in the middle of a sidewalk, it’d be a good idea to retreat to somewhere more sheltered?  (Get a room!)

Ok, everyone move along now.  Nothing more to see here.

 

 

Posted in Prairie Insects, Prairie Natural History, Prairie Photography | Tagged , , , , , | 6 Comments