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Tuesday, July 9, 2024

Alien or Native? How Much Do We Care?

This picture is worth 1,118 words, or at least that's how many we gave it.

What's wrong with this photo? See below. 

We count a dozen native species in the photo above, but there are also three species here that have been called aliens. Some ecosystem stewards focus on aliens; they want them out! Then, whatever happens, whichever species then flourish, regardless of biodiversity, is nature and good. That's one interesting experiment.

At Somme Prairie Grove our restoration experiment seeks to rise to a different challenge: can we restore nature such that it conserves biodiversity, as close as possible to the richness in once achieved. We start with the understanding that nearly all ecosystems of any size in the tallgrass American heartland are damaged and depleted to some degree. They're losing species and alleles of great potential importance to the future of humanity and the planet. Especially those on rich soils. At Somme we inherited a remnant with about 250 native plant species. Thanks to seed gathered from surviving nearby populations of missing species, we now count nearly 500 native species. And yet there are a few aliens mixed in. The photo above shows mostly thriving rare savanna flora. But those three other species raise questions. 

Zooming in, silhouetted against the big prairie dock leaf is the alien grass Redtop (Agrostis alba or gigantea). Although "apparently native in the northern parts of both the eastern and western hemispheres" - it's considered alien here. Or more precisely, according to Swink & Wilhelm, "Much of the population in the Chicago region apparently does not represent a southern extension of the natural range, but rather consists of elements introduced from Europe?" Is it damaging? Should we consider ways to get rid of it? That would be quite a challenge, and we have more pressing concerns.

We could say the same about a second species here, Kentucky Bluegrass (Poa pratensis). Its wispy dried seed heads are visible here and there, if you look close, for example to the left of the prairie dock leaf, just above the budding early goldenrod. Another circumpolar species, this one "almost certainly" consists of European strains today. "It is actually a serious weed in many situations, but in most instances this weediness is not accurately evaluated," reports the Plants of the Chicago Region (1979). But the subsequent Flora of the Chicago Region by Wilhelm & Rericha (2017) tones down the alarm bells. There seems to be less and less of it at Somme over the years, as fire and more competitive conservatives drive it out.  

But the big conceptual adjustment comes with the third iffy species, Yarrow (Achillea millennium). It's an alien in Swink & Wilhelm but upgraded to native in Wilhelm & Rericha: 

"Many have asserted that Yarrow is introduced from Eurasia, although Higley & Raddin (1891) considered it native and common in their time. Willison (1945) reported the observations of the Pilgrims in 1620 at Plymouth, Massachusetts, who mentioned that Yarrow grew in the area."

Zooming in again, yarrow is the creamy white flat-topped flower on both sides of the lavender wild bergamot (below, right). For years we sort of filtered yarrow out of our consciousness as we studied the ecosystem. What is it about yarrow? We never even considered assaulting it, as we did so many plants labeled alien. It seemed more integral and okay.  Wilhelm & Rericha eased whatever angst we had.

None of these three long-denigrated community members do any apparent damage to the whole. In the early years, our best ecosystem restoration experts and mentors used to tell us: have faith! be happy! the high-quality tallgrass ecosystems, managed properly with fire, will in time drive all the bad guys out. 

They were dramatically wrong about some. At least in comprehensible time frames - when it comes to such malignant killer plants as crown vetch, teasel, and reed canary grass - left unchecked they can destroy a healthy, high-quality ecosystem.

To our surprise, some native malignant plants can do the same. In the absence of fire, fine native maples can shade out and destroy the biodiversity of an oak woodland, oaks and all. In the badly damaged but recovering ecosystems of today, species like native tall goldenrod (Solidago altissima) and woodland sunflower (Helianthus strumosus) can in some situations become so dense as to kill off many or most other native species (including some conservatives of importance to biodiversity). We've never seen bluegrass or redtop do that. What's important is not whether a species is alien or native. It's whether the species can be malignant. 

Whether it's considered alien or not, yarrow doesn't seem to do harm. Perhaps some of its genetics these days include imported European strains. Should that make us feel unclean somehow? 

Our goals and principles tell us no. We do not endeavor to restore ecosystems to exactly what they were in 1491. The urgency is for a different goal. Loss of biodiversity, side by side with climate change, is one of the two major threats to life on planet Earth. We can do something about biodiversity, here, now, with our hands, backs, and minds. We do it. And we're so happy for that privilege.

Comment on the plant composition in the photo

Parts of this area have large amounts of such conservative, important, early-season plants as shooting star, hoary puccoon, bastard toadflax, prairie violet, white blue-eyed grass, dropseed grass, Leiberg's panic grass, Junegrass and so many others.  Such species are "everywhere" in a very high quality prairie or savanna. These are spreading by themselves these days but seemingly hadn't spread into this photo yet. 

We wonder whether there is less Kentucky bluegrass and redtop in the areas where more of those high-conservatives thrive. Perhaps early-season conservatives will largely out-compete the two early-season alien grasses in the area of the photo. Worth some study. But then again, we're busy this time of year "hunter-gathering" seeds and killing crown vetch, teasel and reed canary grass. As we learn more, you'll be the first to know. 

The evidence seems to be that very-high-quality remnant prairies (there are no very-high-quality remnant savannas) also have Bluegrass and Redtop. Are they now "naturalized" here as a minor part of the flora most everywhere? The area of this photo is a former cornfield, later pasture, later under ecological restoration since 1980. Random sampling shows that the whole site including the now-best areas continue to improve in conservative biodiversity, growing season after growing season. 

Acknowledgements

Written and edited by volunteer stewards Stephen Packard, Eriko Kojima, Rebeccah Hartz, and Christos Economou.


Ultimate credit also goes to the Cook County Forest Preserves for expertise, resources, and protection of this site since the 1930s. 


The Illinois Nature Preserves System, the institution and its staff, has provided Somme Prairie Grove here with additional protection and scientific resources since 2021, and, as is its mission, forever. 

Endnote

List of species in the photo

If it helps anyone find them, we searched the photo like reading a book, starting top left and reading across a strip covering about the top third of the photo, mentioning only the plants in bloom (color), if any are in bloom. Otherwise we say something about the leaf or whatever. We mention only the first instance of each species. 

Top strip:

Wild bergamot (lavender)

Mountain mint (white)

Early goldenrod (yellow)

Leadplant (purple)

Kentucky bluegrass (in many places but easy to find just left of the prairie dock leaf)

Prairie dock (big green leaf)

Redtop (posting against the prairie dock leaf)

Spiderwort (was blue, but now just some dried flower parts to the right of the tip of the prairie dock leaf)

Middle strip:

Butterfly weed (orange)

Rattlesnake master (white spiky spheres)

Kalm's brome grass (brownish maturing seeds, hanging down)

Heath aster (won't bloom until fall; it's all over this photo ... but most obvious as clusters of tiny heath-like leaves under the Kalm's brome)

Bottom strip:

Big bluestem grass (green and ranging all over) (probably some of the finer leaves are dropseed grass, of which there's a lot in the area, but none is easy to distinguish in the photo).

Yarrow (creamy white)

Animals

Our apologies to the beetles and other little invertebrates visible in the photo here are there. Equally important to the ecosystem, but they need different expertise than we have.

Savanna birds regularly seen or singing in the area of this photo include orchard oriole, eastern kingbird, field sparrow, indigo bunting, yellowthroat, song sparrow, cedar waxwing, and others.

Fourteen companion photos from the same place on the same day

Including some animals and comments, a lot more companion plants, and the first sneak peak at the photo that's subject of this post, click  here


Monday, June 17, 2024

Small Sundrops (Oenothera perennis) in the Ecosystem

“The prime source of all technical achievement is the divine curiosity and the playful urge of the tinkering and pondering researcher.”
Albert Einstein, August 1930

A plant in the ecosystem is profoundly different from a plant in a garden. 

 

Introduction

As the Somme ecosystem slowly reassembles (if in fact that is happening, as we hope it is), we are surprised repeatedly by how its more than 500 plant species interact with the animals and each other.

Somme Prairie Grove is now an Illinois Nature Preserve, as respected and legally protected as biodiversity can get. It’s the first largish (85 acres or 34 hectares) black-soil savanna to be accepted into the system. It received that distinction based on its quality and restoration trajectory, as judged by the Illinois Natural History Survey. But it’s still early in the recovery process.

This is the context in which we study the restoration of this apparently “insignificant” plant - Oenothera perennis or small sundrops. It’s easy to see how one could think it is insignificant. Although some individuals are more than a foot tall, most only rise to heights of a few inches.

This species was added to the Illinois Endangered & Threatened list not long after we started work to restore it.

 Small sundrops conservation status map by NatureServe 
According to the current map by NatureServe, small sundrops is "Secure" in New York, Pennsylvania, and eastern Canada. But "Secure" doesn't mean that it's common over those huge blue areas; it just means that in that state or province there are enough of these plants somewhere that the State is not now worried about it going extinct. NatureServe finds small sundrops to be "Critically Imperiled" in Illinois, Iowa, and Missouri. It has "No Status Rank" in Wisconsin, but in a comment at the end of this post, botanist Dan Carter says he's never found it in southeast Wisconsin and found few elsewhere in the state. 

One of the threats to this species listed by NatureServe is "rights-of-way maintenance." As woods become darker due to lack of fire and invasive species, some species survive best for a time in rights-of way managed by mowing for power lines, pipelines, and roads. Because the corporate managers may resort to herbicides an any time, such populations may be large but insecure. 

Might there be something important in the genes of the Illinois populations? Or - given enormous unfilled conservation needs for other species and ecosystems - is this plant not worth some of our precious time? There’s been too little study to answer such questions definitively. We want to learn as much as we can before we make conservation decisions. But waiting for “hard science” to provide answers before we act seems like the wrong move.

While this post is about one obscure species, we hope we can use it as a prism through which to wrestle with what we may or may not be learning about ecosystem medicine. What differences (if any) are there between original nature and restored nature? All Illinois natural areas are degraded to some degree. Is it possible to restore health and quality to a community of thousands of species? If so, what does it take? And what are the differences between a short, rigorous, small-scale study (a few square meters) and an informal, long-term study on a larger scale (in this case, an 85-acre area)?

Consider the case of another (similar?) species, thicket parsley (Perideridia americana). In 1993, Swink and Wilhelm wrote:

This species is one of those members of a floristic diaspora, which has no discernible habitat in the wreckage of modern landscapes, as if its primal haunt no longer exists. It may well have been a species of open, tallgrass savannas, particularly those that once lined the terraces of our major streams.

Early on, we found thicket parsley at only one site, in a forest preserve across the street from Brookfield High School. A botanist had noticed it there in 1871, Swink re-found it a century later, and we read his book. When we checked we re-found a few plants on the edge of a mowed picnic area, collected a few seeds, and scattered them at Somme in areas of partial sun similar to those we gathered them from. This species now blooms at Somme by the thousands.

Would the same happen with small sundrops?

Thicket parsley now blooms by the thousands in Somme's open woodlands. 

Restoration Methods

As we have done with hundreds of other species, we found and gathered small sundrops seeds from as many nearby populations as we could find, and we broadcast them at Somme Prairie Grove. Also, as we have done with scores of species that seemed to need “intensive care” – we grew this species in backyard gardens to produce vastly more seeds than we could gather in the wild and used those seeds to fortify (and add genetic alleles to?) existing sub populations (sub-pops) at Somme as well as to establish new sub-pops.

In many places, it bloomed by the hundreds for a while. Indeed, it was at some point removed from the T&E list in part perhaps because we and others demonstrated that with a little management it could recover dramatically. But its numbers then fell dramatically in all those places, and most of the little populations were extinguished. Perhaps it was always a rare plant in the savanna? Just how many individuals are needed for it to play its natural role, whatever that is?

Early studies of Small Sundrops at Somme

The histories of the two original sundrops populations (“sub-pops”) we found at Somme are instructive. Sub-pop A, though we searched hard for more, seems to have been only a plant or two where we found it, decades ago. It or they grew on the edge between a “prairie like” opening and a grove of oaks. As we burned and cut buckthorn, it faded out and was gone, so far as we could tell.

Sub-pop B gradually grew bigger. It emerged on the edge of a clearing with an unusual history. This beat-up, living-room-sized area among the buckthorn was littered with cans and bottles, burned campfire circles, and milk crates used for seats. It was a kids’ “party spot”, and we call it the Party Spot to this day. Here the plants grew mostly among alien weeds but also among wild columbine and wild quinine, and the sundrops numbers increased for a while as the weeds dropped out and our restoration progressed.

We weren’t so clever early on as to think of counting such rare plants and keeping track. We do have a record that David Painter collected its seeds for restoration as far back as 1985. Later, when the Chicago Botanic Garden’s monitoring program – Plants of Concern (POC) – began counting small sundrops, the scientists chose the Party Spot sub-pop for monitoring.

By this time though, we had been noticing this species’ dramatic rise and fall in numbers, and we questioned whether the fate of a single sub-pop would lead to a meaningful understanding of the overall population at Somme. The official decision at the time though was that studying more than one would be too much work. Thus we came to the conclusion that, for our purposes, the level of detail needed for proper POC monitoring made the work more onerous than it needed to be. By changing the study design, we hoped we could gather the most important data faster and for more sub-pops, to better reflect the fate of the site’s overall population.

We decided to try to follow all major populations, but in less detail. For example, we mostly recorded only flowering plants (rather than also collecting data on reproducing young and other hard-to-find non-flowering plants), and when there were too many plants to count, we estimated numbers as best we could, rather than resorting to a time-consuming and “more accurate” transect count that was unlikely to be helpfully replicable for a species that “moves around” and “comes and goes.”

Thus at Somme Prairie Grove, as we do our other work, we try to keep our eyes open for new populations. We then try to choose a sampling date when the most sundrops are in flower (which varies substantially from year to year). Then, we try to map existing sub-pops and count all flowering plants that are big enough to see without too much work. In some cases, we estimate the number of plants by counting small subsections and extrapolating to apparently similar areas in that sub-pop.

We also sometimes do a follow-up count for some sub-pops, to account for the fact that flowering happens over a period of time. That is, it’s easier to see plants early in the season when nearby vegetation is relatively smaller and sparser, but not all plants have begun to bloom. A later count may pick up the “late bloomers” but many small plants may be hidden beneath now-taller and denser adjacent In these cases we record the higher count, knowing that some plants will likely be missed, whatever the circumstance.

Some Results

The overall numbers recorded in the early years were as shown below. We worked harder on this species in the first few years, and then mostly focused on other species. (We do not monitor species every year.) In 2017 and 2019, numbers plummeted.

Year

‘04

‘06

‘09

‘11

‘12

‘14

‘16

‘17

‘19

Number of plants

602

339

598

558

372

244

853

77

31

Number of sub-pops

6

8

9

18

4

16

15

4

9


The high counts of early years seem largely meaningless to us now. There would be big numbers in one area for a few years and then no plants there at all. The high counts were areas where seed was sown on bare ground following brush removal. In 2019, although we recorded plants in nine places, only one sub-pop had more than five plants. In two of those sub-pops, we never again found plants. In fact, one sub-pop (in a formerly brushy, now open prairie-like area) had 507 plants in 2009, 43 in 2016, and none in the last three counts. (The prairie vegetation is doing great there.)

But as we look at numbers since then, we see something different: 

Year

2020

2022

2023

2024

Number of plants

128

102

112

217

Number of sub-pops

15

11

9

11


Some sub-pops are gone. Some appear to be sustaining themselves. Will they extinguish more slowly, with this species being lost from this preserve? Will sub-pops always be establishing in new areas and dying out in others? We found the two sub-pops discussed below to be suggestive of improved restoration strategies, for now at least – especially when examining associated plants (see Endnote 2). 

These two relatively stable sub-pops seemed not to reside in the communities focused on by Wilhelm and Rericha (wet-mesic sand prairie, dry-mesic sand prairie, and mesic black-soil prairie) but instead in wet-mesic savanna (sub-pop Q) and dry-mesic savanna (sub-pop X).

Sub-pop Q first appeared in 2009, reached a high of 293 in 2012, plummeted to 5 in 2019, but rose to 107 in 2024. Significant associated species included the somewhat conservative winged loosestrife, cat-tail sedge, Illinois rose, cowbane, and sweet black-eyed Susan – suggesting that the sundrops was holding its own among stiff competition. But associates here includes such indicators of low quality as oxeye daisy, tall goldenrod, and buckthorn – suggesting that this area has a long way to go before reaching relative sustainability.

Sub-pop X first appeared in 2014 with three plants, reaching 25 plants in 2020, and clocking in at 32 plants in 2024. This sub-pop has smaller numbers than some, yet this sub-pop is relatively rich in high-conservatives including northern dropseed grass, purple and white prairie clovers, prairie violet, leadplant – which by themselves might suggest prairie but also Seneca snakeroot, violet bush clover, and cream gentian – which in the Somme experience might suggest savanna – along with such species as shooting star, Leiberg’s panic grass, and Kalm’s brome – which might suggest quality and grow in both prairie or savanna. See Endnote 1: Learning about Communities from Seed Mixes.

Below is a photo of about one third of Sub-pop X:

The twelve flags above each mark one small sundrops plant in Sub-pop X. This part of the sub-pop was mostly in the shade at 3:40 PM when this photo was taken. These plants would have had full sun for most of the morning and mid-day and again in the later afternoon. Does this much temporary shade make a difference. It seems to. We don't seem to find small sundrops among quality associates in prairie or very open savanna. This area would be appropriate for our "Mid-savanna Lo-pro" seed mix. See Endnote 2: Associates and Changing Niches.


Is this competent science?

At Somme, we are both restoring and trying to study restoration at the same time. There’s limited time to do either, let alone both. Hopefully understandably, we are comfortable with the “informal” nature of our studies, knowing full well that some of the “rigor” that goes into “hard science” is sacrificed. Will some important principle or practical advantage emerge for more definitive study? We hope so.

Some people have charged us with not doing real science because much of our data was imprecise or subjective (impressions and judgments) and because we did not take data on control sites to compare our efforts with. While there’s value to these concerns, we have argued that we have actually been doing a larger and more challenging (and possibly more important) experiment than the ones our critics preferred. To start with, our experiment has so far lasted more than four decades, which few comparable experiments do. And our focus was a plot of 85 acres (34 hectares). To paraphrase Stuart Pimm, most ecological study fails to elucidate many ecological phenomena because the studies concern only one or a few species, over one or a few meters or hectares, for only one or a few years – but most ecological process require more species, bigger acreages, and longer time frames to truly reveal themselves.

The “quick and dirty” or “less time consuming and detailed” study process we’ve described requires judgment. Since this judgment varies subjectively from person to person, the study might not be as replicable as most “hard science” aspires to be. Despite its imperfections, studies like this one give us valuable information. Imperfect or incomplete data is still data. We are all forced to make decisions based on imperfect data all the time. It’s also an open question, what kinds of “rigor” are needed – or most useful – to study something as complex as an ecosystem?

For what it’s worth, small sundrops now seems to be gone from the "sub-pop" that our mentors initially encouraged us to focus on. But on the bright side, the overall Somme populations seems sustainable at least on the scale of decades, and the study, experiments, and stewardship are far from over.

There is no “sure science” here. But there is “enough science” to suggest approaches to our dual objectives of giving a chance to rare species and facilitating restoration of overall ecosystem quality.

In 1994, Jerry Wilhelm included a thoughtful comment under the treatment for downy yellow violet (Viola pubescens). He and Swink had cut the species smooth yellow violet (Viola pennsylvanica) from Plants of the Chicago Region. These two yellow woodland violet species apparently hybridized or otherwise blended with each other sufficiently that it seemed no longer appropriate to consider them separate species. In that context, he wrote:

It will be interesting, as savanna and woodland restoration efforts mature in the coming decades, to see if these two elements will sort themselves more discretely.

Yes, a great many questions may be answered, over the decades, and we can endeavor and hope that restoration and natural areas management will be sufficient to teach us what we need to know for gene, species, and ecosystem survival.

Yellow Dots on the Left

The photo above compares the more common species, prairie sundrops (on the right) and small sundrops, the focus of this post (on the left). You might have to zoom in to see the small. Here also, if you look close, these two sundrops species are growing with such prairie and savanna conservatives as downy phlox (in bloom, above left), alumroot (in deer-protection cage), Short's aster, Leiberg's panic grass, showy goldenrod, Davis' sedge, small skullcap, wood betony, shooting star, and smooth white lettuce. 


Endnotes


Endnote1: Learning about Communities from Seed Mixes


Dividing nature into communities helps us think about and conserve them, but communities are an artificial human construct …
 
Using community names to develop seed mixes may help restore nature, but our experience suggested that the seed mixes (and thus the community names?) have needed revision …
 
Initially we used the communities as defined by the Illinois Natural Areas Inventory. The North Branch Prairie Project restored prairies with seed mixes based on those community definitions and on associates (see Endnote 2) as listed in Swink and Wilhelm.
 
Early restoration attempts convinced us that the “savanna” community had been wrongly defined and helped change the scientific understanding of that community. Similar attempts taught us that the community “woodland” had to be separated from “forest” – which many others have realized and that “split” has now become standard among many scientists and organizations. 
 
These days, every year we gather the seeds of hundreds of species of rare plants, sort them into mixes, and broadcast them into recovering ecosystems of various types. It would be impractical to try always to think individually about each of our 500+ species. We could sow all seed everywhere and “let nature sort it out.” But we are able to gather much of our most important seed in small quantities, and we want to sow it where it will have the best chances. 

Background of the Community Idea

What we now call prairie, savanna, woodland, forest, sedge meadow, fen, bog, and other ecological communities were poorly defined until surprisingly recently. Perhaps they’re still poorly defined. Definitions differ from state to state and from organization to organization. “The science” has no consensus. Why have states played a major role? In his book The Vegetation of Wisconsin, Professor John Curtis took the first crack at it in 1959, defining 34 plant communities – various types of forests, prairies, barrens, fens, bogs, and others. Then the Wisconsin Department of Natural Resources took up the challenge of conserving such plant communities. Illinois followed up with the Illinois Natural Areas Inventory in 1978, identifying 88 types of surviving ecosystems. Not just plant communities now, Illinois included animals in its definitions and such aquatic communities as pond, lake, and six kinds of streams. Most states have since then done something similar. With no scientific consensus and no leadership at the Federal level, states took up the challenge of saving their local biodiversity. Conservationists could not wait, because little-funded ecosystem science wasn’t moving all that fast, and rare, surviving healthy communities were being lost at a troubling rate.

There was a reason that the Midwest had an important role to play in the development of ecosystem thinking. Remnants of millennia-old “natural communities” survive here on rich soil (unlike in Europe or the eastern U.S.), and the communities received special study, in part because they survive and are rare and because the exploitation of these rich resources rapidly brought wealth and universities to the region, while some nature survived. In the late 1970s, when the Illinois Natural Areas Inventory was completed, the high-quality remnants that survived here turned out to comprise only one one-hundredth of 1% of the original.

No high-quality prairies or savannas larger than a few acres were identified in that study. That’s too small for most animal species (and thus possibly also not sustainable for plant, fungi, and other species). That fact inspired some of us to try to invent ways to restore larger high-quality communities. Battered large remnants at Somme, Poplar Creek, Nachusa, Midewin, and many, varied other places have been transformed, often by intense and dedicated efforts.
Learning by Doing

We focus on restoring remnants. That's very different from planting a prairie or forest on a former corn field. Even in degraded remnants (as most are) we hope that our approach will conserve the substantial biota - including plants, animals, fungi, bacteria, and others - that survive especially well in larger and diverse sites. Thus, we don't plow ever and don't herbicide most existing vegetation before we broadcast out seed.

Some species will establish when we broadcast seed into the bare ground areas that often result where we cut brush. But most of the higher-quality, high-conservative species will not. Yet they will establish if their seed is sown into good-quality communities – when we learn to choose the right ones. We study the landscape and existing species to help decide which of our many seed mixes would be appropriate for a given spot.

Our first high-quality results came from broadcasting seed into "old field" vegetation, typically a mix of some quality species with typically larger amounts of poverty oats, blue grass, Queen Anne's lace, timothy, early goldenrod, etc. We found that high conservatives (typically rare or non-existent in corn field restorations) did well from the beginning, including such species as prairie clovers, dropseed grass, prairie gentian, shooting star, little bluestem, and many others.

That work was all done long ago, and now we work to expand such "easy success" areas, where often such aggressive species as tall goldenrod, poison ivy, gray dogwood, and others comprise a barrier to the establishment of most of the conservative species that are the rightful goal of biodiversity plant restoration (and on which most diverse animal species in turn depend).

Thus has emerged a new generation of "Lo-pro" seed mixes.

Our Newest Generation of Seed Mixes

Nearly all of the species we planted at Somme have established, apparently sustainably, in the degraded but remnant prairies, savannas, woodlands, and wetlands here. 

Over the decades we found that our planting mixes function better if more targeted. After long evolutions, the seed mix lists are now divided according to four factors:
  • Wetness
  • Shade
  • State of quality or recovery
  • “Lo-pro” or not.

So, for example, we might have mixes with names like “Wet-Mesic Prairie Lo-pro,” “Rough and Ready,” or “Mesic Closed Savanna,” and “Mesic Woodland Lo-pro.” To decide which seeds go where, we look hard at what’s now there:  

Wetness categories: Do existing plants and other factors encourage us to believe that an area needing seeds is:

  • Dry
  • Dry-mesic
  • Mesic
  • Wet-mesic or
  • Wet?

Shade: For years we used one category and one seed mix to cover a range of from 5% canopy to 80%. That was too much. It didn't work efficiently. So now the range use for our seed mixes is articulated like this:

  • Forest
  • Woodland
  • Closed Savanna
  • Mid Savanna
  • Open Savanna
  • Prairie

State of quality or recovery categories: Which of the mix types below will lead to the best results in which areas to be planted?

  • Rough and Ready (a few species that can compete with bad weeds or on especially poor soil)
  • Regular (a full list, but with smaller amounts of conservative species)
  • Turf (mixes that focus on conservatives, to be planted in an existing turf of higher quality vegetation) 
Lo-pro or not: Lo-pro mixes are for places where existing vegetation has a “low profile” – that is existing plants are short and often sparse. Typically bare ground is visible between plants.

The “Lo-pro” mixes have emerged during the last few years as our best means of restoring the most important and most difficult species to our prairie, savanna, and woodland restoration areas. The forerunner of these mixes was adopted by the North Branch Restoration Project (and called “turf mix”) to stop wasting especially rare, conservative prairie seed in recent brush-cut areas.

At the strikingly high-quality woodland remnant at Army Lake, many of us noticed that the grasses and forbs (wildflowers) included the same species as were prospering in our woodland restoration areas. But the plants were much shorter, more diverse, and joined by others with which we’ve had little success. Some plants do best (or recover only) in areas with so much conservative competition that all plants are shorter than most other existing “remnants” or restorations.

The lo-pro areas we identify are varied. In some cases, allopathic species like pussytoes seem to have created the needed space. In other places, it's less obvious; perhaps the soil was damaged somehow? But increasingly we create artificial, therapeutic lo-pro areas by mowing with scythes or string-trimmers. This approach seems to hold promise for recovery of health and biodiversity.

We will continue to report on what we learn.

Endnote 2: Associates and Changing Niches


This year we chose to record the associated species of what may be our two most significant sub-pops. We considered "associates" to be all plants growing within 1/4 meter (10 inches) of each of the small sundrops. 


The first, sub-pop Q, is currently the largest, 107 plants, and has been around since first restored and then monitored beginning in 2009. Fifteen years may be a brief span ecologically, but it sure beats the many sub-pops that seem to have faded out altogether. These 107 plants grow in a wet swale, partly shaded in the mornings by oaks to the east. 


In the tables below, C = Coefficient of Conservatism and W = [wetness]

Note: the "Wetness Index" should probably be called the "Dryness Index" as higher numbers indicate drier habitats.


Associates of Small Sundrops at Sub-pop Q


Scientific Name

Common Name

 C

W

Aster novae-angliae

New England aster

4

-3

Carex squarrosa

narrow-leaved cattail sedge

10

-5

Chrysanthemum leucanthemum

ox-eye daisy

0

5

Coreopsis tripteris

tall coreopsis

5

0

Fragaria virginiana

wild strawberry

1

1

Galium triflorum

sweet-scented bedstraw

5

2

Glyceria striata

fowl manna grass

4

-3

Juncus dudleyi

Dudley’s rush

4

0

Liatris spicata

marsh blazing star

6

0

Lycopus americanus

common water horehound

5

-5

Monarda fistulosa

wild bergamot

4

3

Oxypolis rigidior

cowbane

7

-5

Panicum implicatum

old-field panic grass

2

1

Penstemon digitalis

foxglove beard tongue

4

1

Poa pratensis

Kentucky blue grass

0

1

Pycnanthemum tenuifolium

slender mountain mint

7

0

Rhamnus cathartica

common buckthorn

0

3

Rhus radicans

poison ivy

2

-1

Rosa blanda

early wild rose

5

3

Rosa setigera

Illinois rose

7

2

Rudbeckia subtomentosa

sweet black-eyed Susan

9

2

Solidago altissima

tall goldenrod

1

3

Solidago gigantea

late goldenrod

4

-3

Solidago graminifolia

grass-leaved goldenrod

4

-2

Spartina pectinata

prairie cord grass

4

-4

Veronicastrum virginicum

Culver's root

7

0

 

The other sub-pop that seemed to merit this level of study in 2024 was first noticed in 2014 and had many fewer plants, two to five in most years. This year, in our first quick count, we found seven. But, looking back, we had recorded 25 plants here in 2020. The plants here were all small, so X seemed to deserve a second count. Thus, we upped the number to 16 plants. 


Over the years, most substantial populations had been found in wetlands, like sub-pop Q. But sub-pop X was much drier. On the wetlands scale of -5 (deep water) to +5 (driest hilltop), sup-pop Q ranked -0.2 while sub-pop X ranked 2.5. (The Wetlands Index perversely gives higher numbers to the driest plants. It perhaps should be called the "Dryness Index".) This difference is significant enough that of the 55 species found with the sundrops at Q and X, only three were on both lists.  


Another major contrast was that the plants growing with sundrops at sub-pop X were much more conservative. Mean conservativeness at Q was 4.3. At X it was 6.5 - a highly significant difference. The area of sub-pop X was much more advanced is ecosystem recovery and stability. To record its associates, we tiptoed among all those conservatives and placed a flag next to each small sundrops plant that we found. With that level of scrutiny, we found a total of 32 little plants, doubling our previous "more careful" count. 


Associates of Small Sundrops at Sub-pop X

Scientific Name

Common Name

 C

W

Amorpha canescens

lead plant

9

5

Aster ericoides

heath aster

5

4

Bromus kalmii

prairie brome

10

0

Coreopsis tripteris

tall coreopsis

5

0

Cornus racemosa

gray dogwood

1

-2

Desmodium canadense

showy tick trefoil

4

1

Dodecatheon meadia

shooting star

6

3

Eryngium yuccifolium

rattlesnake master

9

-1

Gentiana flavida

yellowish gentian

9

3

Helianthus strumosus

pale-leaved sunflower

5

5

Lespedeza capitata

round-headed bush clover

4

3

Lespedeza violacea

violet bush clover

7

5

Liatris aspera

rough blazing star

6

5

Lobelia spicata

pale spiked lobelia

6

0

Monarda fistulosa

wild bergamot

4

3

Panicum leibergii

prairie panic grass

10

2

Parthenium integrifolium

wild quinine

8

5

Pedicularis canadensis

wood betony

9

2

Petalostemum purpureum

purple prairie clover

9

5

Poa pratensis

Kentucky blue grass

0

1

Polygala senega

Seneca snakeroot

8

3

Pycnanthemum tenuifolium

slender mountain mint

7

0

Silphium integrifolium deamii

Deam’s rosin weed

5

5

Silphium terebinthinaceum

prairie dock

5

3

Solidago juncea

early goldenrod

5

5

Sorghastrum nutans

Indian grass

5

2

Sporobolus heterolepis

prairie dropseed

10

4

Veronicastrum virginicum

Culvers root

7

0

Vicia americana

American vetch

7

5

Viola pedatifida

prairie violet

9

4

Zizia aurea

golden Alexanders

7

-1

 



 

Thus, the cast of characters is huge, and the drama continues to unfold. Stay tuned for more fun in the years ahead.  


References


Swink and Wilhelm Plants of the Chicago Region 1994 Indiana Academy of Science

Wilhelm and Rericha Flora of the Chicago Region 2017 Indiana Academy of Science


Acknowledgements


This post is by Christos Economou, Eriko Kojima, and Stephen Packard.
Thanks to the staffs of the Cook County Forest Preserves and the Chicago Botanic Garden for collaboration and inputs of many kinds. 

The authors of this post have combed the scientific literature and appreciate all the facts and insights found there. On the other hand, most of what we’ve learned of ecosystem recovery processes we've learned by doing and from others dedicated to similar work. The list of people who deserve credit in this light is very long, but we'd like to acknowledge Aldo Leopold, Robert Betz, Ray Schulenburg, Tom Vanderpoel, and Rich Henderson. 
 
Thanks to Katy Chayka for the beautiful close-up photo at the top of this post.