Exposing Artifacts

Six generations of kids have hunted for arrowheads and buffalo bones along Kanaranzi Creek. But, in the last two or three years it seems like the high water levels have opened up a treasury of cultural resources. An archaeological survey of Rock County and two adjacent counties done in the early 1980s demonstrated that most sites are located along streams. There are currently 94 formally documented sites in Rock County listed by number in the Office of the State Archaeologist. Of those, 11 are classified as “artifact scatters” that have both lithic and/or ceramic artifacts; these may be habitation sites. Two of those sites with artifact scatters are located on Lone Tree Farm.

This summer, prehistoric corn cobs were found at the western site (21RK0019) and a piece of pottery was found at the eastern site (21RK0082). These are small and light-weight items that have probably been carried by the Creek from eroding steep channel banks and deposited on nearby sand bars called point bars. This map shows areas of erosion (areas in red) and deposition (areas in yellow) between 2016 and 2018. It’s speculated that erosion of the upstream steep, eroded banks has exposed archaeological features such as cache pits. The artifacts that are washed away are subsequently deposited at specific locations on the downstream adjacent point bars.

The light-weight piece of pottery and corn cobs were found near slow-moving, low water at the position where mud and sand have been deposited. The fragments of bone associated with the pottery and cobs are really small and don’t weigh much. Higher on the sand bar where fast-moving high water has deposited sand and coarse gravel, the pieces of bone are much larger and heavier. The photo on the left is of larger fragments from higher on the bar at the west site (21RK0019) where the corn cobs were found down close to the low water level. The photo on the right shows small bone fragments found with the piece of pottery on the lower part of the sand bar at the east site (21RK0082).

When the water is high, the current is strong and large pieces of bone or even big complete bones are dropped on the upper part of the sloping point bar. When the water level is low, the current is weaker so only small pieces are carried and deposited at a lower position on the sand bar. The left photo shows the locations big bones and little bones on the sand bar at the west archaeological site and the right photo shows the sand bar at the east site.

Record rainfall in 2018 and 2019 produced sustained high water flow conditions that ripped up a lot of the pasture. These fast-moving currents dropped some really big bones on the upper parts of the sand bars. Many medium-sized bone pieces were deposited at intermediate positions on the bars. These may have been shattered and cut during butchering; several buffalo skulls have been found at both sites. Some of the pieces almost look like tools, such as awls. However, it’s hard to really interpret their significance because they have been moved out of their original location in a buried archaeological feature. Context is super important and only systematic, professional excavation will lead to a realistic understanding of what happened here a thousand years ago.

There are, however, important implications for the archaeological sites along the Rock River and its tributaries in Rock County. Artifacts and bones may be deposited on sand bars just downstream from eroding steep channel banks that are cutting into buried archaeological features. This could be a serious threat to cultural resources that warrant “salvage” archaeological excavations.

Posted in Earth Science, Farm History | Tagged , , , | 1 Comment

Conservation Crowdsourced

Back in the 1940s the US Department of Agriculture’s Natural Resources Conservation Services (NRCS) was called the Soil Conservation Service (SCS) and as a young beginning farmer my dad was using that as an information source. For example, we’ve got a file folder with a five-year crop rotation plan that’s a stark contrast to the two-year corn and beans rotation that is the current convention. He also grew and harvested brome seed as a part of the SCS involvement. There’s a family story of Dad turning brome seed by hand as it dried on the cement floor of the Sheep Shed. But, ideas and information sources evolve through time.

The smooth brome did a good job of suppressing weeds in the Creek pasture and it provided excellent fodder for cattle. The pasture is still dominated by tall smooth brome with Kentucky bluegrass as the understory close to the ground. The left photo shows new growth in a paddock recovering from grazing and the right one shows mature, ripe brome in a paddock not grazed this year. The cattle prefer the tender new growth as they’re rotated from paddock to paddock. However, the stiff stalks of the ripe brome can jab them in the face and cause eye infections.

We do have paddocks seeded to warm season grasses, but we’d like to diversify some areas from dominant brome to include native cool season grasses and other native plants. This is the seed tag from a commercial mix that I tried to frost seed by hand earlier this year. It would provide diversity because it had dominantly wild rye in it’s four main grasses plus about forty other species, including half a dozen plants that are found on one of the native prairie remnants that we’ve identified in the pasture. Problem is, it’s hard to see that anything really grew in part because a lot of the species are not easy to identify….at least for me. Also, I just had to take what was available in the commercial mix that only had a few species overlapping with the native plants we knew grew in the pasture.

And, THAT’S where the crowdsourcing comes in! I posted a question in a Face Book Group asking for suggestions on cool season grasses to replace brome and I hit a bonanza of information! Nine different people responded with the names of eight specific plant species and half of them were on our list from the native prairie remnant. That’s an important consideration because it demonstrates that those are species included in the existing indigenous seed bank in the pasture. It’s like a test of whether to include a specific species. What’s more, three of the respondents suggested wild rye grass that was also the dominant component of the commercial seed mix. Although rye is not currently on the list of plants in the prairie remnant, it already does play a significant role in one of our renter’s operation.

Growing, harvesting, and marketing rye for cover crop seed is one of the new enterprises that our renter has started. The photo on the left is a seeder specifically designed to plant rye for a cover crop. As a good cover crop, rye keeps roots in the ground to reduce erosion and increase soil health. In addition, combined with radishes and turnips, rye is a second crop that can be planted after beans have been combined or corn has been chopped; that mix is good for cattle grazing. But, wait! There’s more! If it’s not grazed, the more mature rye can be chopped for silage and fed away from the field. The photo on the right shows silage piled, waiting to be hauled away. AND, it turns out that rye can be the main component of a mix of cool season grasses used to increase diversity in the brome-dominated pasture.

Here’s some final information about the Face Book Group that provided the crowdsourcing. Although it’s called the “Minnesota Prairie Landowner Network”, the information generally has application in the tall grass prairie in adjacent states. I think that it just got started this year, so it’s a relatively new outfit and maybe that’s why I got such timely and useful input. There are about 275 members from diverse backgrounds including landowners, agency experts, nonprofit staff, and people who seem mainly just interested in prairie environments. The posts tend to be a lot of wild flower pictures and discussions about prairie restoration. But, if the responses to my initial inquiry are any indication, there’s plenty of information shared that relates to regenerative agriculture in a working landscape and that can be a help for folks who are actually farming the land.

Posted in Farm History, Life Science | Tagged , , , | Leave a comment

Place-Based Stacked Experiences

That’s a weird title! It’s trying to communicate that some places seem to host multiple experiences that don’t seem to be related. But, sometimes these “coincidences” have a common thread, other than sharing a specific location.

This picture taken in the early 1920s shows my dad and his older sister fishing with a view of the farm buildings to the south at the top of the wooded hill. The tall tree may be the large cottonwood that’s still there or it may be the actual Lone Tree itself because it didn’t fall down until 1930. This is about where the homesteaders’ children and grandchildren played along the Creek in the prior fifty years. It’s also very near the place where our children and grandchildren have fished, launched rafts, waded, and collected artifacts and bones and memories of adventures. That all happened from the 1970s up to the present time. But this is also the location of an exciting adventure that Dad had back in the early 1940s.

He was riding a horse parallel to the channel but back away from the edge of the steep bank when a beaver den collapsed under them and they fell into the hole! Fortunately neither the horse nor the rider was hurt, but it was a traumatic experience. The photo on the left shows the opening of a probable beaver den that I found last just week. It’s in almost exactly the same place as the accident, so Margaret and I did a “survey” (mostly just wading in the Creek, taking photos, and whacking at the exposed bank with a geology pick). The tunnel extends about six feet back into the bank and is about six feet from the top of the bank.

The high channel bank has a complex set of layers. The upper part is light-colored sand and dark-colored silt and clay deposited by the Creek. Below that is a layer of dark, soft clay above older glacial gravel exposed just to the north (left) of the photo. But, the opening to the beaver den is located right at water level in extremely hard gray clay that’s probably glacial till. It would be really tough digging for the beaver. The photo on the right is a view downstream from the den in the high bank toward the sandbar where an important artifact was found this past week.

The low water exposed sediments that most likely eroded from the high bank with the beaver den. This piece of pottery may have been carried by the current to the sandbar from the eroding bank. What if the beaver had help digging in the hard glacial till? What if he was actually just cleaning out a prehistoric cache pit exposed in the steep Creek bank? And, maybe that’s also what had happened back in the 1940s. Maybe Dad and his horse fell into a collapsed cache pit weakened by a burrowing beaver.

The piece of pottery is significant because it can be used to tell time. I sent a picture of it to a friend who is an archaeologist with expertise and he identified it as from the time of the Great Oasis people, about 1000 years ago. He also thought that it’s from a different vessel than the first piece of pottery that we found in this area. You can see some of the artifacts and bones at this post , see a picture of the first piece of pottery at the this post and see illustrations of cache pits here.

Posted in Earth Science, Farm History, Life Science | Tagged , , , | Leave a comment

Battling Brome



Prairie restoration programs often involve attempts to eradicate or at least limit smooth brome. This invasive, non-native, cool season grass is a vigorous sod-maker that usually expands to turn a pasture into essentially a monoculture. I understand why the restoration folks want to get rid of it, but it is also excellent for grazing. So in an attempt to diversify our brome and blue grass forage base, we’d like to find a way to locally control and replace brome.



We’ve got about a dozen patches of native prairie marked by big bluestem as the main indicator plant. The August 5 post linked here describes four of them. Among the dozen prairie patches, two are warm-season plantings, but the others are from preserved indigenous seed banks. Most locations are in areas where the stand of brome is thin, like obvious west-facing hill slopes. But, other locations seem to be associated with subtle small-scale topographic features. In this post we’ll relate a cluster of three prairie patches (circled in blue) to slight topographic highs and propose an experiment on a planted prairie patch (circled in red).



This past week a lot of the corn in our neighborhood was chopped for silage. This photo shows a “wall” of corn that illustrates the influence of subtle micro landforms in a floodplain setting. Green stalks mark wetter topographic low spots and brown ripe stalks spread over the subtle adjacent high spots. It’s a pattern that’s also seen in the brome and blue grass pasture.



This map has two-foot topographic contours that give a suggestion of subtle highs and lows that can be clearly seen when you’re actually walking the ground. More detailed elevation data would be helpful, but this information available from the county is adequate. There are limited stands of big bluestem mixed in with the brome on the subtle topographic high spots. However, the intervening low areas shown by brown blotches have no bluestem in the more dense brome development. This is essentially a top view of the pattern shown in a side view in the field of chopped corn.



The planted patch of big bluestem near our house has been established for about seven or eight years. However, in the last three or four years Margaret has maintained a mowed path around it. There’s been an on-going debate about this mowing. I hate to do any more mowing of tall grass (brome or bluestem) than is necessary, but she likes the trimmed look better. This year we noticed that the bluestem seemed to have expanded out toward the east and north mowed paths. Did the mowed brome at the margins of the patch allow the bluestem to expand through the root system or maybe the dominant wind from the south has dispersed bluestem seed to the north?



These two photos show the ground view of the two mowed paths. On the left, the bluestem with its distinctive red stalks, has reached the edges of the mowing on the east. On the right, the bluestem is also at the edge of a mowed area on the north. But, this is a newly mowed strip (marked by the brown grass) next to the long-maintained path (showing as the green area with brown grass clippings to the right). So, this is an experiment. Will the bluestem expand out into the mowed brome? Also, will Margaret be the ultimate winner of this long-standing debate about mowing the tall grass?

There are numerous anecdotes about native prairie plants expanding out of road ditches and fence lines. Maybe this unmanaged process can be replicated to coax expansion of established prairie patches on local subtle high spots out into the surrounding areas dominated by thick brome. Managed disturbances like grazing or burning (or mowing or spot spraying or even flooding) on the margins of the micro landforms may encourage the bluestem to grow out into the stressed brome. This might be an example of “precision conservation” because the topographic features that host the native plants are so small and subtle. In any case, this localized approach may provide an alternative to the wholesale conversion of brome-dominated paddocks.

Posted in Earth Science, Life Science | Tagged , , | Leave a comment

Prehistoric Corn Cobs

As Kanaranzi Creek erodes away the steep banks on the outer edges of meander loops, archaeological “treasures” continue to emerge and be deposited on adjacent sand bars. We think that’s what happened at the site described in the post of June 17 at this link. And, we think that it has also happened near the oxbow that hosts the pond and wetland described in many of the other recent posts. The newly-discovered “treasures” at the oxbow are corn cobs!

The Native Americans, who farmed river bottoms in this tall grass country 500 to 1000 years ago, raised corn along with squash and beans (a.k.a. the “three sisters”). They stored the corn in pits buried in the ground. These images are from displays at the Visitor’s Center at Good Earth State Park near Sioux Falls. The top of one of these cache pits in the floor of a dwelling is shown on the left and on the right we can see how the ears of corn were arranged in a side view. After the cache pit was emptied, it was often filled with trash and refuse.

Last fall, after several seasons of high water and erosion, I found this projectile point on a sand bar near the oxbow. Over the past 20 years, numerous buffalo bones have eroded out of the steep creek banks around the oxbow, including the skulls on the left and at the top of the second photo. In addition, there’s a circular vegetation anomaly in the area. About one-quarter mile upstream, the circular plant patterns at that site had expression in geophysical mapping recently described in a paper in the Minnesota Archaeologist by Megan Messerole. She interprets the mapping as expressions of cache pits and a possible dwelling and there are also artifacts and buffalo bones at this studied site. Now it looks like there may be a new, similar site near the oxbow where the contents of another cache pit may be eroding out of the Creek bank.

After the water levels dropped earlier this month, I fund more than two dozen corn cobs on one sand bar. They looked small and skinny and old….prehistoric? Online archaeology sources indicate that the prehistoric corn raised by Native Americans had 6 to 10 rows of kernels on each cob, while modern varieties generally have 16 to 20 rows. So, all that I had to do was count the rows. However, there is also another pattern that suggests erosion of a cache pit.

If the cobs came from a nearby, eroded bank, this was probably the only sand bar that had them. So, I went back down into the pasture and checked out four sand bars upstream and four downstream. This map shows that the upstream bars had no corn cobs and that three of the four downstream bars each had one cob. That’s exactly the way old-time prospectors would pan for gold. They’d follow the “color” upstream until they found the “mother lode” that was shedding the gold onto stream sediments. The eroding cache pit was probably in the steep bank circled on the air photo just upstream from the cob-rich bar, although there’s no sign of it currently shown in the bank.

But, are these really prehistoric corn cobs? They do look smaller than today’s familiar sweet corn. And, counting the rows of kernels on 17 of the best-preserved cobs supports the idea of ancient corn cobs. The counts ranged from 6 to 9 rows on each cob and had an average of 8. That’s well below the range of modern corn cobs. And, that’s also why the cobs on the right have pins stuck in them. The pins mark the row counts that provide the data. However, these prehistoric corn cobs are probably “treasures” only for old retired guys who are interested in archaeology!

Posted in Earth Science, Farm History | Tagged , , , | Leave a comment

The “Navy” on Kanaranzi Creek

The Creek comes into our pasture about .7 of a mile above the bridge on the State Line. However, that’s the straight-line distance; it’s more than twice that far along the meandering channel. Those measurements are taken from the air photos available from the County. There have been several generations of many families who have operated as the “Navy” on Kanranzi Creek. And, they’ve used a wide variety of “vessels” but it’s all been fun!

Over the Fourth of July holiday this year one of our neighbors, a family of four, went canoeing on the Kanaranzi. It’s actually a family of five, but the oldest girl is in her own home with her new baby. So, these are actually new grandparents and an uncle and aunt! The grandmom probably floated the Creek as a kid, at least we know that she spent time down there.

A few years ago, the boys from another neighborhood family floated the Creek in inner tubes like this one, but theirs had air in it. They usually made the trip when the water level was high and the ride was fast. These days, the water level is low so you might have to get out and carry your craft and leave footprints in the mud. Also, there are now a lot of trees that have fallen from the eroded banks, so maybe you have to get out and carry your craft around a fallen tree in the channel.

Going back forty years, our own kids floated in the Creek on a rubber raft that their grandpa got for them. So, this is still another type of “vessel” in the “Navy”. This is also the sand bar where one of them was “attacked” by a monster (snapping turtle) from the deep. Going back even farther in time, brother Bob and I built rafts out of tree limbs, fence posts, and scrap lumber, but none of those rafts floated very well!

Back before boats were made of rubber or fiberglass, Bob and I got an old wooden rowboat from one of Dad’s uncles. We were thrilled because it worked better than our homemade rafts. However, the following spring the flood washed it away and sank it. Years later, erosion exposed the boat and then another flood buried it again. One of my grandkids helped me dig in a sand bar looking for it, but we had no luck. There’s also supposed to be buried treasure along Kanaranzi Creek, but that story will have to wait for another post.

Posted in Family History, Farm History | Tagged , , , , | Leave a comment

Extraction, Restoration, or Regenerative Agriculture

We’re glad that we live in a neighborhood of diversified farming operations. Naturally, the Kanaranzi Creek valley dictates that grazing and livestock are one way for the pastures to pay their way. The corn and beans on the surrounding uplands generally have a different business model and landscape management than the grazing areas along the floodplain.

In order to live and work in a rural setting, people have to be able to make a living. Row crops have provided some great opportunities in the past, although not so much currently. Industrial agriculture is a corporate construction that tends to extract a return from the available natural resources like soil and water, but it also exploits local human resources and doesn’t pay for a variety of intangible benefits. Agronomy may be a data-based science, but it has been harnessed into a huge supple chain infrastructure that makes flexibility and resilience very difficult. Most of the recent “shortages” during this past year have been because of problems in the infrastructure rather than problems with producers. To paraphrase an old country song: “Oh Lord, it’s hard to be NIMBLE.”

I’ve recently been listening to some “Prairie Podcasts” put out by the Minnesota Department of Natural Resources. You can Google it to get some excellent environmental science with some practical suggestions on how to apply that science to manage the land. The presentations are geared to prairie restoration because that’s what the DNR is supposed to do, among other things. They’re just responding to their funding source. But, it’s hard to establish what the restorations are supposed to look like. Pre-settlement landscapes are a commonly cited target, but even the Native Americans actively worked with the land. And as a State agency, the DNR is mainly dealing with public lands to provide short-term excursions for people who live in cities to go hunting, fishing, hiking, biking, and canoeing. That’s different than the private lands along the Kanaranzi Creek, which are mainly a “working landscape” where people are trying to earn a living and living on the land for multiple generations.

There is an emerging new way to look at farming opportunities. It’s currently called “regenerative agriculture”, but most of the ideas have been around for a long time. It’s not the old organic farming model, but regenerative ag does pay attention to soil health and is getting a lot of “buzz” from both consumers and producers. Some of the earliest information sources have come from two independent farming operations, one in central North Dakota and one in central South Dakota. But, now big industrial ag companies and big governmental agencies are getting on board with the concepts. The simplified check list of best management practices is basically a balance of economics and ecology: 1) use cover crops to keep the soil covered; 2) integrate livestock into a diversified operation; 3) rotate both row crops and grazing paddocks; and 4) minimize soil disturbance with reduced tillage. These are not new ideas, but are now being pulled together into a new business model that aims to improve soil health and keep people on the land.

We’re lucky to have renters who are engaged in these best management practices. Some of our neighbors are doing some of the suggested things, but the Leuthold Family Farm is doing them all. And, they’ve been doing most of the practices for several generations even though it hasn’t been called “regenerative agriculture” until recently. What it could be called is: “working with Nature to put together a successful farming operation”. That’s basically the message from the farmers in the central Dakotas who were early advocates of regenerative ag. To emphasize the business aspects, one of those guys says, “It’s better to sign the back of the check than the front”. And, “Reducing input costs goes a long way towards increasing profits without increasing production numbers”. The Leuthold family is doing all of that and has been doing that for several generations. Congratulations to Dan and Amy for being recognized as the Rock County Outstanding Conservationists of the year.   

Posted in Farm History, Life Science | Tagged , , , | 2 Comments

Tracing Native Prairie

Big bluestem, aka turkey foot, is a warm season grass that’s pretty easy to identify in a native prairie. That’s because it ripens to a distinctive purple-red color this time of year. And, the top has a shape like a bird’s foot that’s easily recognized. So, it’s an indicator plant that helps to track and trace native prairie. Big bluestem is also a common component of commercial prairie seed mixes, probably for similar reasons.

We’re grateful to have at least four separate patches of big bluestem on the Farm: 1) roadside, 2) house yard, 3) prairie parcel, and 4) grazing paddocks. The four areas are different sizes, have had different histories, have different levels of biodiversity, and probably have completely different types of disturbances influencing their growth. This post has a long shot of the general setting and a close up photo of big bluestem from each of the four areas.

The first area is along the edge of the gravel road that is the state line between Minnesota and Iowa. It’s small and sparse, but it’s a unique natural planting of native grass. Ten or fifteen years ago Kanaranzi Creek routinely flooded over its channel banks in the spring. After one of these annual spring floods the water covering the road at this location apparently carried grass seed because then we started seeing big bluestem along the roadside. The associated plants in the ditch are mainly “weeds” but do include milkweed. So this is a relatively small, thin patch that was seeded by a natural process and has a relatively low diversity of associated plants. It is, however, subjected to a fairly regular disturbance when a grader maintains the gravel road.

The second area is in our house yard and was planted with a commercial seed mix ten years ago. It was a fairly simple mix that had little bluestem and Indian grass in addition to big bluestem, but it is mainly the distinctive big bluestem that has survived. Although the patch is reasonably robust and dense, it seems to be contracting every year under pressure from the surrounding smooth brome. The area is somewhat larger than the roadside patch and the initial low grass diversity has decreased even more. Fortunately there are a number of other associated plant species as you can see in the photos. We’ve burned it two or three times, so there has been some disturbance to cut back on the thatch and reinvigorate growth, but it’s not a particularly healthy native prairie.

The third area is a patch of native prairie that has probably been located on this unplowed, west-facing hill slope for centuries. The post from July 15, 2020 (https://lonetreefarm.blog/2020/07/15/weeds-and-feed-learning-from-a-prairie-hill/) describes this part of the pasture in more detail. It’s a one-acre parcel that has been excluded from grazing for about ten years, but this year it was integrated back into the paddock system. There’s a high (40 species) diversity of mostly native plants that have apparently grown from the soil seed bank, which has been “storing” native seeds for generations. The big bluestem seems somewhat sparse because grazing has resumed, but the overall diversity is very high compared with the other three areas. We probably should have done periodic burning, but now the grazing will provide some annual disturbance.

The fourth area is about fifteen acres currently subdivided into three paddocks. In 2015, the parcel was converted from row crop cultivation and planted with a commercial seed mix of five warm season grasses (big bluestem, wheat grass, side oats grama, switch grass and Indian grass). For the first several years there was no grazing, but establishing this as a warm season paddock complex has not been simple. Initially, Chinese elm seedlings had to be sprayed; then two record-setting wet years brought out seeps and springs that changed the vegetation; and finally the competition from smooth brome has been incessant. Now, one of the three warm season paddocks is in pretty good shape with vigorous big bluestem, but the other two will need some work and possible re-seeding. 

There are at least half a dozen other patches of prairie marked with diagnostic big bluestem in our two hundred acres of pasture. Like the four areas described in this post, the other parcels contract and expand from year to year with varying weather conditions and disturbances by grazing. However, what’s unique about all of these additional prairie remnants is that they, like the hillside exclusion, probably have all developed from the soil seed bank where native species have been dormant and preserved for many years. This may represent an important resource that’s an alternative to expensive commercial seed mixes and provide a gene pool of local species. But, how do we go about “waking up” these native prairie seeds and get them going again? That’s not a rhetorical question. We would really appreciate some practical suggestions!

Posted in Life Science | Tagged , , , | 2 Comments

Mother Trees on the Prairie

There’s a growing body of scientific evidence that trees share information, warning their neighbors about danger and nurturing nearby small trees. If you Google “trees communicating” you can get some notion of the traction that this idea is getting. Trees appear to communicate through their root systems and have measurable biochemical reactions to threats of stress. Much of the original work has been done in dense forests like those in the Pacific Northwest, but it may also provide some insights into little trees on the prairie.


This stand of cottonwoods is just down the Creek from our house and you can see it’s distinctive shape from our porch. The tallest and oldest trees tend to be toward the middle and the smaller younger trees are out at the edges. This gives the top of the grove an arch shape—-actually there are two arches shown on this photo. So, are the mature trees near the centers of the clusters providing information, protection, and nurture to the juveniles out around the margins?


Wild plum thickets in our Creek pasture show similar shapes, although the patterns are somewhat harder to see when the individual clusters are close together. The spring blossoms make the thickets look like a single mass. But, if there’s a smaller thicket standing alone you can see the same arched top. The elders toward the centers are providing care for the kids on the outside edges.


Inside the thicket, the trunks of individual plum trees seem to reinforce the pattern. Generally, in the internal tangle of trunks, you see the mature larger trees toward the middle and the immature smaller trees out at the margins. The left photo is a view from the center toward the margin and the right photo is a view from the margin toward the center. These are taken in the fall after the leaves have dropped so you can see the trunks easily. Actually, the individual plants at the margins are more like shrubs or bushes and the individuals in the middle are really only relatively small trees.



Looking down on the complex overall plum thicket from the perspective of these air photos (available online from Rock County), we can see that it’s actually a cluster of clusters. Single, sub-circular constituent clusters coalesce into a relatively continuous mass that makes it hard to distinguish the outlines of individual clusters. Some of the most obvious ones are circled. But, again a smaller, isolated thicket shows the distinctive sub-circular pattern: mature in the middle and juveniles at the margins. Walking through an isolated thicket, the perspective from “boots on the ground” usually supports the generalization.




We’ve got an experiment going in one of the paddocks. A single mature tree and her surrounding offspring are fenced off and protected from grazing. If this “exclusion” works and the little ones grow up to make a new thicket, this might be a way to expand the stands of wild plums along the Creek. That would be a good thing because in hot weather the cattle use the shade to get protection from the sun.




Here’s another example of an arched plum thicket, but this one also shows an emerging threat. Increased erosion of the steep channel bank has cut into the plum populations all through the pasture. In fact, the single small tree in the center of this photo is all that remains of a thicket almost completely removed by bank erosion. On a more hopeful note, the cottonwood monarch on the right is probably more safe than it was because the active bank erosion has shifted to the left farther away from the root system.

Although the idea of nurturing mother trees has a certain anthropomorphic appeal, there is an alternative interpretation. Maybe the canopy of the tall older trees cuts sunlight and moisture off from the short ones, so the young ones can only thrive out on the more bare margins. Like so many things in Nature, the reality is probably a dynamic between competition and cooperation (and probably many other variables). But, an over-emphasis on competition has apparently limited our understanding of the important lesson of cooperation among trees until recently. Maybe the mother trees on the prairie can provide some insights into what’s currently going on in the world of humans?

Posted in Life Science | Tagged , , , , , | 5 Comments

Oxbow Mystery

OXBOW MYSTERY

When a channel cuts through the steep bank in a meander loop there’s a distinctive landform produced called an “oxbow”. This blog has a number of posts describing our oxbow because it’s a cool complex of unique small environments in the Creek pasture. These are each different ecologic habitats that support different populations of plants and animals. You can use the “Search” box to find some of the other posts about oxbows, but this post is about a specific critter in particular environmental setting.

This air photo has the several small constituent subdivisions labeled on the overall oxbow. The upstream and downstream plugs separate the oxbow from the main channel and the tie channel further separates the channel from the pond. The pond and the wetland are the main components. If the water level is high enough, they both get water from the main channel. However, when water levels are low the pond is sustained by groundwater flow from a buried gravel aquifer exposed in the steep north bank. The wetland, on the other hand, has completely dried up at times when low water levels are maintained. The oxbow mystery is located in the pond-wetland transition.

The pond-wetland transition seems to be the home of a colony of rare little frogs called cricket frogs. Like Topeka Shiners, they are a native species found in prairie streams. They have a distinctive call that sounds like two rocks striking together. Here’s a link to the post that describes this little guy and his voice: https://lonetreefarm.blog/2019/07/03/frog-calling/

These frogs are usually first heard in the late spring. In 2017 it was June 11; in 2018 it was May 24; in 2019 it was July 1; and this year it was June 12. But, this year I noticed a peculiar pattern. The only place that I heard these distinctive calls was in the pond-wetland transition. I checked the other main parts of the oxbow another 3 or 4 times after June 12, but the pond-wetland transition was the only place where the cricket frogs called.

Why do these little guys like that particular part of the oxbow? The plants along the bank close to the water seem to be basically the same as in other subdivisions. Is there some water quality aspect related to the ground water that flows into the pond? Are there particular food sources like distinctive insects in this transition zone? Do other colonies of cricket frogs have a similar preference for a distinctive environment similar to this transition zone?

It’s a “puzzlement”.  

Posted in Earth Science, Life Science | Tagged , , , | 1 Comment