Photo of the Week – September 6

Well, August was an awesome month for my square meter photography project.  An unbelievable number of insects visited my little plot of prairie during the month, many of them drawn by the abundant and very charismatic Maximilian sunflowers.  After a lot of sorting and decision-making, I ended up with well over 150 high quality photos from the month.  I’m sharing 18 of those with you here.

I started this project with the hope of inspiring people about the beauty and diversity of prairies.  What I didn’t expect was the degree to which I, myself, have been inspired and affected by the project.  The diversity of life I’ve recorded has been amazing, but the process of slowing down, focusing in, and appreciating what I find in a tiny space has become a powerful experience for me.  Rather than feeling like I’m missing other photographic opportunities by returning over and over to the same little spot, I actually find myself wishing I was there when I’m not.

Anyway, I hope you’re enjoying these updates along the way.  I’m working on some ideas for how to share the entire project after the year is over.  If you have suggestions along those lines, please feel free to share them!

This beetle is feeding on the leaf of a Maximilian sunflower plant.
There was only one stiff sunflower plant in my little plot, surrounded by many more Maximilian sunflower plants. I tracked the progress of that stiff sunflower plant, anticipating the diversity of insects I would find on its flowers.  However, as soon as that sunflower bloomed, it was attacked by a horde of little beetles. I will admit being emotionally affected by that attack…
Once Maximilian sunflowers started to bloom, they drew insects like huge magnets, including lots of these little hover flies (aka flower flies and syrphid flies)
It wasn’t just the flowers that attracted insects. Early in the month, I found this cavity with something shiny and brown inside it. I never figured out what was in there, and didn’t want to bother it since it was inside my plot.
A few weeks after the previous photo, I found another cavity in another Maximilian sunflower stem. Same kind of insect? I have no idea.
Soldier beetles were astonishingly abundant this month, both on sunflowers and elsewhere.
While soldier beetle abundance was on the upswing, Japanese beetle abundance was declining. I haven’t seen one in a couple weeks now.
Many of the insects I’m finding are really really tiny, including what I’m pretty sure are itsy bitsy wasps. If you look very closely, you can see one silhouetted against this flower.
Another example of tiny insects – I only saw this little fly because I was photographing the leaf axil of Indiangrass and the fly entered the frame.
I had seen this plant hopper species elsewhere in Lincoln Creek Prairie, and was thrilled to finally catch one in my plot.
This aphid was feeding on a Maximilian sunflower before it flowered.
The smoke from western wildfires created hazy skies last month, but that haze made for some nice photo light, including a photo of the sun itself.
I thought this plant hopper (?) was just an empty exoskeleton until it started moving while I photographed it. Astonishingly cool.
Sunflowers weren’t the only bloomers in August. Grasses were also in full bloom, including this big bluestem plant.
Indiangrass started blooming right at the end of the month, and this hover fly took advantage of the easy access pollen.
This hover fly was resting between flowers on a dewy morning.
After seeing them all over the prairie around me, I finally found a mantis inside my plot. This one is the European mantis.
While I was following the above European mantis around the plot with my camera, I came across this Chinese mantis, also in the plot. Two mantis species in the same day!

 

Japanese Beetles in Prairies – How Much Should We Worry?

Japanese beetles (Popillia japonica) first appeared in the U.S. back in 1916 (in New Jersey) and have been spreading west since then.  They’ve only started to be abundant in our part of Nebraska during the last several years.  As a result, I’m not really sure what to expect in terms of potential impacts to our prairies.  I’m largely writing this post to hear what my friends to the east have been seeing, since the little buggers have been around there longer.

Japanese beetles are known pests of gardens and crops, but what are their impacts in prairies?  This one was eating the flowers from leadplant (Amorpha canescens)

While I’m not sure what to expect in prairies, our family has had plenty of experience with their ability to damage our garden crops.  Japanese beetles wiped out our raspberry crop last year and were trying really hard to kill our little apple tree this year.  I’m not a fan.

For those of you not familiar with Japanese beetles, they are about 1/2 inch long beetles that are metallic green with brown wing covers.  The series of white spots around the edge of their abdomen are actually little patches of white hairs, and those help distinguish them from lots of other metallic green beetles.  The larvae feed mostly on the roots of grasses, and they are a big pest in lawns and other turfgrass situations.  As adults they’re known to attack over 300 different plant species, with corn, soybeans, maples, elms, plums, roses, raspberries and grapes among their favorites.  Hence, they are pretty unpopular with gardeners and farmers alike.

Adults emerge in the early summer and seem to spend the vast majority of their time eating and mating – often at the same time.  Females take breaks from feeding/mating to burrow a few inches into the soil in grassy areas and deposit a few eggs.  Then they come back out and join the crowd again for a while.  They can repeat their burrowing/egg laying up to 16 times a season.  Most adults live for about a month or month-and-a-half, but some can live up to 100 days or more.  They are skeletonizers of plants, meaning that they feed on the portions of leaves between the veins, leaving behind only the skeletons of those leaves.

Japanese beetles skeletonizing leaves of Illinois tickclover (Desmodium illinoense)

I’ve been trying to pay attention to Japanese beetles in prairies, but I don’t feel like I’m learning very much yet.  The biggest infestations I’ve seen have been in the small prairies here in Aurora (Lincoln Creek Prairie).  In bigger prairies outside of town, I don’t see nearly as many.  At Lincoln Creek, the beetles feed on a lot of different plants, but seem to have special attraction to tick clovers (Desmodium) and the flowers of roundheaded bushclover (Lespedeza capitata).  However, while I’ve seen many plants nearly covered with beetles, many others manage to successfully bloom and make seed, so I don’t yet see the beetles having any major impacts.

Japanese beetles  feeding and mating on roundheaded bushclover (Lespedeza capitata)
Despite a heavy presence on Illinois tickclover flowers and leaves, many plants still produced seed this season, at least at Lincoln Creek Prairie in Aurora, Nebraska

Help?  What are those of you in the Midwest and further east seeing in prairies that have had decades or more of Japanese beetle infestations?  Any evidence that they might wipe out particular plant species?  Should we be concerned about them in our Nebraska prairies or just focus on protecting our gardens and crop fields?

Any advice is welcome – thank you.

Square Meter of Prairie Project – July 2018

Quick note – registration is still open for the 2018 Grassland Restoration Network workshop (September 5-6) in Illinois.  Click here for more information and/or to register.  It’ll be worth your time!

The square meter photography project continues!  Throughout this calendar year, I’m trying to document as much beauty and diversity as I can within a single square meter of prairie along Lincoln Creek in Aurora, Nebraska.  Today, I’m sharing some of my favorite images from July.  If you want to look backwards, you can click to on these links to look at selected photos from June, May, and January.

July was a little slower than I’d expected, to be honest (August, however, has been really hopping).  I was surprised how few pollinators showed up to feed on the butterfly milkweed plant in my little plot.  (I’m sure it didn’t have anything to do with the loony guy and his camera looming nearby.  There were lots of insects hanging around on butterfly milkweed plants elsewhere in the prairie…)  Regardless, there was still plenty going on in the plot last month.  Here are some highlights.

One of the few bugs I did see on the butterfly milkweed plant in my plot kept playing hide and seek with me.  This was the only photo I could get on this particular day.
A few days after the above photo, I saw the same kind of bug again, but this one was more tolerant of my lens in its face.
Morning dew drops.
I’m not sure what this beetle is, but I saw it a few times last month.
This tiny spider was hanging out one day.  It looks similar to the lynx spider I was seeing in June, but the eyes are wrong – and it seemed to be making a web.
Purple prairie clover (Dalea purpurea).
A leaf-footed bug (I think?)
I believe this intricately-patterned little beauty is a leaf hopper. Any guidance as to species would be appreciated…

A Closer Look at Prairie Roots

One of the biggest jobs of a prairie steward is to manage the competition between plants, ensuring that no species becomes too dominant and no species is pushed out of the community.  In our prairies, much of our effort is directed toward some of the stronger grass species, including big bluestem, indiangrass, smooth brome, and Kentucky bluegrass.  Left unchecked, those grasses (and a few others) can monopolize both light and soil resources and reduce plant diversity.  Our management targets those grasses with fire and grazing, often using season-long defoliation by cattle or bison to weaken the competitive ability of those grasses, opening up space and resources for other plants to flourish.  Our long-term plant data show that we’ve been able to maintain species richness and a full complement of plant species with this kind of management.

When those major grasses are weakened, one of the most obvious responses is a flush of “weedy” vegetation that quickly takes advantage of the soil and light resources that have become available.  Research has shown that growing season defoliation temporarily causes grasses to abandon some of their roots (until defoliation stops and the grasses recover), opening up space for nearby plants to grow larger and more abundant.  However, there are still many questions about the actual physical responses of grass roots to defoliation, and gaining a better understanding of that could be really important to prairie managers.  Researchers at Kansas State University are actively working on those questions right now.  Dr. Jesse Nippert, in particular, has done a lot of work on this subject, including some work on prairie shrubs that I wrote about a few years ago.

Last week, a couple of Jesse’s graduate students, Seton Bachle and Marissa Zaricor, were at our Platte River Prairies, collecting data on roots under grazed and ungrazed conditions.  In addition, Seton brought along a nifty tool called an air spade, which uses compressed air to dig into prairie soil with enough force to expel soil particles, but not so much that it tears apart the roots of plants (with the exception of the tiny rootlets at the tips).  Seton and I started talking about a year ago about the possibility of getting the air spade up here so we can look for visual evidence of grazing impacts to roots.  Marissa and Seton are both doing very in-depth (ha!) measurements of plant root responses, but I also wanted to see what’s those roots really look like.  The air spade seemed like a great way to do that.

Here is our sampling area, as seen by our drone. The bottom right portion was burned this spring and has been grazed fairly intensively since. The top left portion is unburned and has had very little grazing pressure.
Dust erupts out of the ground as Seton excavates with the air spade.

For this initial trial, we chose a part of the prairie that was burned this spring and was being grazed intensively by cattle as part of our patch-burn grazing management.  Abundant rain this year has meant that the cattle aren’t keeping the grasses as short as we’d really like, but we were still able to find some big bluestem plants that have been cropped pretty short.  As a comparison, we went across the burn line to part of the prairie that hasn’t had much grazing pressure in recent years and, because it is unburned, hasn’t had much attention from cattle this year either.  As a result, we were (ok, Seton was) able to excavate around the roots of big bluestem plants that had been grazed off to just a few inches of leaf height, as well as ungrazed plants with leaves around 12 inches high.

Here is the excavation spot in the burned/grazed patch.
Here is the unburned/ungrazed excavation site.

As Seton started blowing soil away from the roots (and I photographed the process with my camera and our drone), one of the first things that became obvious was the relatively shallow depth of the main root mass.  The work of J.E. Weaver and others has shown that prairie plants, including grasses, have some very deep roots.  However, more recent work, including that of Jesse Nippert of Kansas State, Dave Wedin at the University of Nebraska, and others, has shown that those grasses don’t appear to actually use those deep roots for much.  In fact, grasses tend to concentrate the vast majority of their root masses in the top foot or so of the soil profile, effectively monopolizing most of the moisture and nutrients there.  Forbs tend to pull most of their resources from below that, and shrubs work at even greater depths.  I’ll write about this more in a future post, but for now, just trust me when I say that this is abundant evidence for this (and many more questions being pursued).  Prairie grasses can have deep roots, but it’s the incredible root density at shallow depths that they most rely on, even during drought.

With the air spade, we could pretty easily see that most of the big bluestem roots were in that shallow depth, and only a few extended down below that.  However, as Seton pulled out fully-excavated clumps of big bluestem shoots and roots, my initial reaction was one of disappointment.  There didn’t seem to be any obvious difference in the density of roots or size of the overall root mass between the grazed and ungrazed plants.

Marissa and Seton examine the roots in the partially excavated grazed site.
Seton examines some of the roots dug out of the burned/grazed site.

My immediate thought was that because these plants had only been exposed to grazing for about a month, maybe there hadn’t been enough time to see changes in their root masses.  In addition, it might be that some of the roots were no longer active, but were still connected to the root mass for now.  We’ll be repeating this excavation process later in the season, and might see differences then that aren’t yet obvious.  In addition, we’ll look at some roots of grasses that were heavily grazed all of last season and see what those look like.  Still, I was a little disappointed not to see a bigger visual difference.

However, when Seton and Marissa looked at the roots, they pointed out something I hadn’t initially seen because I was so focused on root length and density.  The diameter of most of the roots of the ungrazed bluestem appeared to be considerably larger than those of the grazed plants.  We were working with a small sample size, but among all the plants we dug up, that size difference seemed to be pretty consistent.

An ungrazed clump of big bluestem on the left and grazed on the right.  You can’t see the length of all the roots in this image (they were similar between plants) but the ungrazed roots are noticeably thicker than the roots of the grazed plant.
Here’s another look at the difference in root thickness between the grazed plants (top) and ungrazed (bottom).

Marissa explained that thicker roots have more carbohydrates stored in them.  Plants that have been defoliated, and are trying to regrow shoots, have to pull carbohydrates from their reserves to do so – pulling them out of their roots and putting them into aboveground growth.  Whether those roots kind of deflate as the carbohydrates are pulled from them or stressed plants just create skinnier roots is something Marissa and Seton are hoping to learn from their work.  Regardless, carbohydrate storage plays into competitive ability.  Grasses rely on their storage capacity to fuel growth and withstand further stress, so differences in root diameter could be part of the answer to why grazed grasses are less competitive.  Seton and Marissa plan to examine some cross sections of the roots we dug up to see if they can see more under a microscope than we could by just looking at the roots with our naked eye.

Seton and Marissa’s actual scientific explorations will give us much better answers to questions about grazing impacts on grass roots than simply looking at a few samples, but it was fun to see the actual roots themselves.  While the differences between grazed and ungrazed plants weren’t as stark as I’d expected, I’m still looking forward to our next effort later this summer – especially because all I have to do is photograph the results of the hard work Marissa and Seton are doing!

If you’re interested, here is a short 1 minute drone video showing the excavation process.  You can also check out Seton’s science website here.

Special thank you to the Nebraska Environmental Trust for funding our drone purchase through a PIE (Public Information and Education) minigrant, administered through the Nebraska Academy of Sciences.

A Plot-Sized Biodiversity and Photography Project

Today, I’m beginning a new photography project aimed at exploring and celebrating the small scale diversity and complexity of prairies.   I’ve picked out a 1 x 1 meter plot in a small patch of restored prairie here in Aurora, Nebraska, and I will be photographing everything I can within that tiny area over the next year or so.  My objectives are to find and document as much beauty and diversity as I can and to show the dynamic nature of prairie life, even at a very small scale.

Lincoln Creek Prairie, with the yellow flags marking my square meter plot.

The plot sits in a narrow strip of land restored in the 1980’s by Bill Whitney and Prairie Plains Resource Institute.  I picked Lincoln Creek Prairie because it’s right across town from me, and therefore easy for me to get to frequently.  It’s also a great restored site that was planted with a diverse mixture of prairie species (over 100 species) and is well-established.  However, the prairie is small enough that it doesn’t host any grassland-nesting birds or other animal species that need relatively large and open prairie habitats, and suffers from all the other issues that come along with tiny prairies.  I anticipate that most or all of the organisms I photograph during the coming year will be plants and invertebrates, but I’m confident that I won’t find a shortage of subject matter.

A view of the 1 x 1 plot from above

I didn’t pick the small plot randomly, but I also didn’t try to find a spot with more diversity than any other nearby.  Instead, I looked for a place that would catch the light well during most of the year but was out of the way enough to not be disturbed by people hiking the nearby trail.  I freely admit that I chose the exact location of the 1 x 1 plot because it has a butterfly milkweed plant in it – it’s a nicely photogenic species.  This isn’t research, after all, and I don’t have to select my plot in a completely unbiased way!  However, I’m confident that the 1 x 1 plot I chose is representative of the rest of the prairie around it.

Switchgrass (Panicum virgatum) with a flower that never completely came out of its sheath last summer.

I began my photography journey within the plot yesterday, and took the photos you see here in this post.  I’ve already discovered one big challenge regarding my plans – it’s going to be difficult to avoid crushing or breaking the vegetation within the plot during my frequent visits.  I don’t see any way to avoid matting down the vegetation around the edge of the plot, but I’ll try not to do any more of that than necessary, and hopefully that won’t excessively impact what I see inside the plot.

The curled and dried leaf of stiff sunflower (Helianthus pauciflorus)

Right now, the plot is fairly uniformly brown, and perhaps drab looking from a distance.  However, I didn’t have much trouble finding interesting shapes and textures to photograph during the 10 minutes or so I spent there yesterday.  Even without green vegetation or crawling invertebrates, there was plenty to look at.  That bodes well for the coming year, I think!  Stay tuned…

Maximilian sunflower (Helianthus maximiliani) seed head, minus the seeds.  Birds, mammals, and/or other creatures likely picked it clean last fall.
A butterfly milkweed (Asclepias tuberosa) seed pod on a curled stem.

Pondering Winter Wildlife Cover From My Comfy Couch

It’s a good ol’ fashioned blizzard here today.  As I’m sitting snugly in my warm house, I’m feeling a little badly for some of wildlife out there in the snow and wind.  The boys went outside to play in the snow for a little while, and both of them spent most of their time building shelters from the weather.  Many wildlife species, of course, migrate to warmer places or find/build themselves underground burrows to overwinter in, but there are some animals out there in the prairie right now, and this has to be a bad day for them.

Calvin was able to dig out a little shelter in a drift. He was still pretty glad to come in and get some hot chocolate a few minutes later…

Sitting here on my comfortable couch, I’ve been thinking about the prairies I manage or help with, trying to remember what kind of cover is out there.  Overall, I feel pretty good about the situation.  Our shifting habitat mosaic approach involves providing a wide range of vegetation structure types in each of our prairies, including everything from short sparse vegetation to the kind of thick dense cover wildlife are probably seeking out today.  Nelson  (our Platte River Prairies land manager) and I have periodic conversations in which we try to envision ourselves as creatures that prefer various habitat types.  How far would we have to travel to find cover?  If we burn one patch of dense cover, where is the next closest patch of similar cover, and what would animals have to travel through to get to it?  We have a lot of factors to consider and balance as we discuss management plans each year, so it’s always helpful to see the world through the eyes of the various species that will have to live with (literally) the decisions we make.

To be completely honest, I probably don’t think enough about winter cover as I’m trying to consider the perspective of various creatures.  I’m more often thinking about nesting habitat for birds, breeding cover for small mammals, or sunning areas for invertebrates and reptiles that need to thermoregulate during the growing season.  Days like today are a great reminder that while all those considerations are important, at least some species will probably live or die based on what kind of shelter they can find during winter storms like the one roaring outside right now.

Many parts of our family prairie have pretty short vegetation structure during the winter, but we always try to leave some patches of taller grass as well.  This is kind of in-between.  It’s not really dense enough to provide great cover from the wind, but has places for small animals to hide while they’re out feeding.

I’m thinking today about meadowlarks, for example.  As I’ve walked our prairies during the last month or two, I’ve seen a lot of meadowlarks flying around in small groups.  My understanding is that meadowlarks that breed around here head south to Kansas or Oklahoma, and the ones we see during the winter come from up in the Dakotas.  In other words, meadowlarks don’t migrate en masse to one general destination.  Instead, each bird just goes a little southward from where they spent the summer.  I wonder if they each wait until they start seeing birds from the north show up and then head south to get away from the crowd…

Regardless, birds like western meadowlarks need some kind of shelter out in the prairie on days like this.  We know a lot less about the winter habitats used by grassland birds than we do about summer habitat use, and as far as I know, no intrepid biologist has yet gone out to see where meadowlarks or other birds are hanging out during blizzards.  (If you’re an intrepid biologist who HAS done this, please let me know!)  I think it’s fair to assume that most birds (and any other wildlife who aren’t underground) try to get out of the wind during this kind of storm.  It’d be interesting to know whether they stay in open grassland and look for tall dense vegetation or venture into brushy or wooded areas where they might not normally go.

Somebody is apparently sheltering in place under the snow here.  Probably not a meadowlark…

Not knowing much about individual wildlife species and how they each choose to shelter from winter storms, I guess the best strategy is to provide as many habitat types as possible so they can all find what they need.  That way, meadowlarks can forage in short or “weedy” areas during pleasant sunny days, but move to a nearby patch of dense grass (or whatever other cover they like) when they need to nestle in thatchy vegetation and get out of the wind.

Here in our comfy house, we’ve been talking about trying to fix the drafty corner of our kitchen, where one of our walls needs a little better insulation.  Our poor little feet get cold when we’re making toast on windy winter mornings!  It’d be really nice to get that fixed.  On the other hand, it’s just the kind of hardship that helps me understand what meadowlarks are going through on days like this.  I bet their feet were cold at breakfast time too…

 

Meadowlarks could learn from opossums, who either take over abandoned burrows from other mammals or find a nice wood pile to shelter in during cold weather and blizzards.

Photo of the Week – October 13, 2017

My favorite photos tend to be those I’ve taken most recently.  I imagine that’s true of most everyone who does any kind of creative work.  I have a tab at the top of the home page for this blog called “Prairie Photos” where you can see some of my favorite photos.  The other day, I looked through them and realized it had been way too long since I’d updated that page, so I remedied that.  Now you can click on that tab (or just click here) and see a batch of some of the photos I’m most proud of.  Here are a few examples…

This photo of prickly poppy (Argemone polyanthemos) was taken this summer.  I think I mainly like it for its simplicity.

Most of the photos included in that collection were taken within the last couple of years, but there are a few older ones that I still like.  Often, those older photos captured a particular moment of serendipity that still evokes strong emotions for me.  Other times, they were the the final result of a lot of trial and error, and my pride in the image comes as much from that effort as from the quality of the photo.

This image of a crab spider and ant was taken back in 2013.  I was photographing the spider when the ant unexpectedly appeared.
This 2015 photo of stiff sunflowers in restored prairie along the Platte River still evokes a strong memory of the morning itself.
I honestly don’t know when this photo was taken. It’s a scan of an old slide. While I don’t remember the date (I could look it up) I definitely remember the moment because I’d been trying for years to find a vantage point from which I could capture the landscape diversity of the Niobrara Valley Preserve and this was the first time I felt successful.  Most of the cedar trees shown in the photo are gone now…
I have countless photos of stiff sunfllower (Helianthus pauciflorus), but this 2015 image is my current favorite. I like the color and composition, but also the fact that the petals are only partially elongated, giving it a different look than more mature flowers.
This katydid photo from 2014 is still one of my favorites because of the color and composition, but also because I can see its “ears” so clearly on its front elbows.  I use it often to talk about that fascinating anatomical tidbit about katydids.
When I see this 2015 photo, I can still smell the smoke of the prairie fire that scorched the vegetation on and around the big ant mound. I was monitoring the aftermath of our prescribed burn when I found these ants, and was able to capture the heightened activity of the colony as they scrambled to assess their newly exposed condition after the fire.
I have plenty of early morning photos with dew drops in them, but this one (from June 2016) is my current favorite.

One of my biggest aspirations for my photography is to help people see the beauty of prairies.  If you have friends or colleagues who aren’t yet aware of that beauty, maybe you can send them the link to these photos to show them a few examples.

Do it quick, though, before I get tired of these photos and replace them with newer ones!

Spider Watching

I think this is a juvenile Argiope spider.  With its legs fully spread, it was about the diameter of a quarter, and its web was about the size of my hand.

During a brief stop at our family’s prairie this morning, I noticed a small spider on its web, and set up my tripod to see if I could photograph it.  Just after I got a couple nice photos, a grasshopper nymph blundered into its web, and the spider leapt into action.  I tried to get pictures of it as it was quickly wrapping the little grasshopper, but I only managed one – it was moving quickly, and there was some vegetation in the way.

I managed to get this shot when the spider paused briefly while wrapping the grasshopper nymph. The image is a little fuzzy because I was shooting through some grass leaves, trying not to disturb the action.

However, once it had its prey stabilized, the spider slowed down and I was able to watch and photograph it for the next 10 minutes or so as it waited for the nymph to become sufficiently paralyzed.  When I finally had to leave, the spider hadn’t yet started to feed.  Instead, it was perched above the nymph with two legs resting on the nymph like it was feeling for a pulse.  Every time the nymph twitched, the spider quickly pulled its legs back as if it had touched a hot stove.  Very carefully, I pulled my tripod away and left the spider to its meal.

This was shortly after the spider finished the wrapping process. You can still see the silk attached to its spinnerets (near its rear end).
…waiting for the grasshopper to stop kicking… I assume spider got to eat it eventually, but I had to get to work.

How Small Is Too Small?

What’s the minimum effective size of a prairie?

For example, can a prairie be the size of a kitchen table?  Let’s say someone converted a landscape full of prairie to an immense gravel parking lot, leaving only a round kitchen table-sized parcel of vegetation in the middle.  Is that tiny isolated parcel a prairie?

The question might seem silly, but the question became a useful little thought experiment for me.

That little parcel certainly wouldn’t be big enough to meet the needs of most prairie animals.  Birds, small mammals, snakes, and even smaller creatures like grasshoppers and bees would be unable to find enough food to survive within that small area.  The loss of those animals would affect many of the ecological services and functions that make prairies work.  Those services include pollination, nutrient cycling, herbivory and more.

Even small creatures like grasshoppers would have a hard time surviving in a patch of plants the size of a kitchen table.

Some tiny herbivorous invertebrates might be able to survive in that little parcel of vegetation, but probably not enough of them to support most predators that feed on them.  The lack of predation would allow those invertebrate populations to grow much larger than they otherwise would, leading to significant damage, or even mortality, to the plants they feed on.  Once their food is gone, the invertebrates would starve and die as well.

Plants that manage to survive invertebrate attacks and an absence of pollinators in our little parcel would still face major challenges.  In the long-term, they would probably suffer from a huge genetic bottleneck because they don’t have other individuals of their species to cross breed with.  In the meantime, it would take a lot of intensive and thoughtful management to keep them alive.

Smooth brome and other invaders can quickly dominate small prairie patches without constant vigilance and suppression.

Invasive species management would be a huge problem because it wouldn’t take long for an aggressive invader to quickly dominate that small area.  Quick action would be needed to remove invasive plants as they arrive.  Fire or mowing would also be needed to prevent a smothering thatch from accumulating as plants grow and die back each year.  Unfortunately, every fire would kill most invertebrates aboveground at the time and destroy their food sources.  We could try to burn only a portion of the parcel and save some of the insects, but with such small populations, we’d still probably lose most species eventually.  Mowing and raking might be an alternative, but we’d still end up removing either the invertebrates or their food sources.

Ok, so we’d just have to live without most prairie animals, but we’d still have plants.  Or at least a few of them.  Some of those plants would be more competitive than others, especially in an animal-less environment, so it would take a lot of effort to keep them from pushing the less competitive plants out.  And, of course, we’re assuming the mysterious belowground processes that allow plants to survive would still function in our tiny parcel – microbial relationships that allow plants to access and process water and nutrients, for example.  If those are sufficiently intact, we’d have some plants.

Would that be a prairie?

I’m pretty sure no one would argue that a kitchen table-sized area containing few plants is a prairie.  Even in the first moments after the parking lot was created, I would argue the remaining patch of vegetation had ceased to be a prairie, even though it still contained a reasonable diversity of plants and animals. It wasn’t really a prairie anymore, just a doomed fragment of its former self.

If we can agree that a kitchen tabled-size patch of land is too small, how big would we have to make that patch before we’d be willing to call it a prairie?  What species and/or ecological processes should we use as criteria?

Can we agree a prairie needs to be big enough to support a healthy pollinator community?  Does it need to be able to sustain viable populations of small mammals, snakes, leafhoppers, spiders, and other little creatures?  Is it a prairie if it doesn’t have a full complement of grassland bird species?  Does that requisite bird community include larger birds such prairie chickens or other grouse species?  What about at least moderately-sized predators such as badgers and coyotes (or even bigger ones) or large ruminants like bison or elk?  Which of those components are we willing to live without, and more importantly, which can a prairie live without and still sustain itself as an ecological system?  A prairie without badgers, coyotes or bison is functionally different than one with those animals, but is it a non-prairie or just a different kind of prairie?

Bison herds need very large prairies, but we don’t know as much about the amount of land needed to sustain populations of bees, leafhoppers, jumping mice, or even genetically viable plant populations.

Even if we reach consensus on the key components of a prairie, we’re still hamstrung by our lack of information about how big a prairie needs to be to support each of them.  We have decent data on the prairie size requirements for many grassland bird species, but beyond birds, we’re mostly just guessing.  If we want the full complement of species, including bison and other large ruminants, we’re going to need thousands of acres, but how many thousands?

More importantly, what does this mean for the many remaining patches of prairie vegetation too small to support whatever we decide are the key components of a prairie?  It certainly doesn’t make them worthless, but it might be important to make sure we’re viewing them realistically.  What are the likely ramifications of the missing components?  The absence of prairie chickens or upland sandpipers might be disappointing, but might not have the ripple effect that the absence of pollinators or coyotes might have.  Can we identify and compensate for the absence of key prairie components by managing differently or more intensively?  If not, how do we adjust our vision of the future for that prairie parcel, and how does that adjusted vision affect how much management effort we invest?  (You can read more about the challenges of managing small prairies here.)

For many of today’s small prairie patches, the only chance of preserving their species and ecological functions is to make those small patches larger and/or more connected to others.  Restoring adjacent land back to high-diversity prairie vegetation allows formerly landlocked populations to expand and interact with others, and creates enough habitat for larger animals to survive.  Identifying potential restoration opportunities might be the highest priority conservation strategy for those of us working with small prairies.

Reasonable plant diversity and the presence of larval host plants like this prairie violet have so far allowed our family prairie to support a population of regal fritillary butterflies, but the small size and isolated nature of our prairie means if the butterflies have a bad year, they could easily disappear and never return.

Our family prairie is a little over 100 acres in size, is managed with large ruminants (cattle), and has regal fritillary butterflies, coyotes, badgers, upland sandpipers, and even an occasional prairie chicken.  However, I’m certainly not comfortable that our 100 acre island within a sea of cropland will to sustain a prairie ecosystem indefinitely.  This thought experiment has forced me to think more seriously about prospects for increasing the size of our prairie and building connectivity to other grasslands.  I hope it’s useful to others as well.

Photo of the Week – April 20, 2017

I’ve been enjoying the early flush of wildflowers this spring, and have been trying to photograph them when I get time.  Because I already have quite a few close-up portraits of most of these species already, I’ve been trying to use a wide-angle lens to show the flowers in a broader context.  It means lying prone on the ground with the camera resting either on the ground or on my hand to get both the flowers and the landscape/sky behind them into the same frame.

Pussytoes (Antennaria neglecta) at our family prairie near Stockham, Nebraska.

Pussytoes are an easy one to photograph because they are allelopathic and hinder the growth of neighboring plants.  That short vegetation helps pussytoes plants compete with others, but also makes it easier me to photograph them without stray leaves and other plant parts getting in the way.  For other species, I’ve been spending most of my time photographing the flowers growing in sites that were grazed hard last year.  The grazing makes photography easier, but the access to light and weakened grass competition also stimulates more of the plants to flower than in ungrazed sites.  I’ve been collecting data on flowering plant numbers over the last several days, and the data confirm my casual observations.  There are many more flowers in prairie patches recovering from grazing than in patches that haven’t been grazed much in the last year or two.

Prairie violets (Viola pedatifida) in the area of our family prairie we grazed most intensively last year.
Carolina anemone (Anemone caroliniana) at Gjerloff Prairie, owned by Prairie Plains Resource Institute.  They are having a great year in the part of the prairie that was burned and grazed in 2016.
Ground plum (Astragalus crassicarpus) at the Helzer prairie.
More pussytoes at the Helzer prairie, with a little bit of dried manure for flavor.

For pollinator insects, this early spring period can be very challenging because flowering plants are in pretty short supply.  There aren’t many species blooming, and those that are tend to be spread sparsely across large areas.  At least in the prairies around here, last year’s grazing is increasing numbers of available resources for pollinators, including both short-lived and long-lived plant species.  That appears to be particularly valuable this year, given the number of butterfly and moth species taking advantage of strong south winds to make an early migration to Nebraska.  I can’t remember a year when we’ve seen so many of those insects in April, including monarchs (which we’re now seeing frequently), sulphurs, red admirals and many little moths.

Now, here’s a question I hope someone out there can help answer:  Pussytoes flowers are dioecius, meaning that some plants have male flowers and others have female flowers.  My understanding is that pussytoes is pollinated both by wind and by insects.  If the male flowers produce pollen but the females don’t, what attracts insects to move from male flowers to females and complete the pollination cycle?  Do the female flowers produce nectar?  I see mainly flies, and a few bees, landing on pussytoes.  I don’t think those flies could be accessing nectar from deep inside the flower, and I don’t see any evidence of nectar near the top (or in any part) of the flower.  Also, most of those flies and bees seem to be landing on male flowers, and I rarely see them on female blossoms.  Can anyone help me understand why/how this pollination process works?