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Monday, October 14, 2024

Fox Squirrel - a missing piece in savannas and oak woodlands?

The big, burly fox squirrel is said to be declining, while the little gray squirrel increases. One possible reason is that the big guy needs richer food sources. We've wondered if the fox would increase and the gray decrease as Somme's habitats improve. So far that isn't happening. 

The gray squirrel is oritinally a creature of forest; the fox squirrel's classic habitats are oak savannas and open woodlands. 


Fox squirrel - tough but vulnerable 

We see fox squirrels at Somme from time to time - never more than one or two. This year, I can’t remember seeing a fox squirrel all summer. On October 7, while monitoring birds, I saw two. As for gray squirrels, though I didn’t count, I’m sure I saw at least thirty. 

What's going on? Perhaps there are clues in Wikipedia and other easily accessible literature:

Fox squirrels are most abundant in open forest stands with little understory vegetation [apparently referring to shrubs]. The size and spacing of trees is among the important features of fox squirrel habitat. Fox squirrels are often observed foraging on the ground several hundred meters from the nearest trees.

 What do they mean by “little understory”?

Optimum tree canopy closure for fox squirrels is from 20% to 60%. Optimum conditions of understory closure occur when the shrub-crown closure is 30% or less.

So far so good. Somme has a great deal of low-shrub, open woodland habitat. Red-headed woodpeckers also like such a habitat, and now breeding pairs are widespread and regular at Somme (at least five pairs this year). Is there something else missing for fox squirrels?

Fox squirrels in Ohio are said to prefer hickory nuts, acorns, and black walnuts ... and to be absent where two of these nut-producing trees are missing.

In Michigan, fox squirrels feed on a variety of foods throughout the year. Spring foods are mainly tree buds and flowers, insects, bird eggs, and seeds of red maple, silver maple, and elms. Summer foods include a variety of berries, plum and cherry pits, fruits of basswood, fruits of box elder, black oak acorns, hickory nuts, seeds of sugar and black maple, grains, insects, and unripe corn. Autumn foods consist mainly of acorns, hickory nuts, beechnuts, walnuts, butternuts, and hazelnuts. Caches of acorns and hickory nuts are heavily used in winter.

We have good quantities of most of the above, including maples and elms, although we're working to reduce the former and the later die of Dutch elm disease. 

Juveniles usually disperse in September or October, so perhaps the occasional fox squirrels we see at Somme are dispersing from successful breeding habitat elsewhere. But where? And what do those places have that Somme does not?

One mixed-message fact about fox squirrels is that they do well in some suburban neighborhoods. Human preferred landscapes often have the scattered trees and open understory that the fox squirrels need. Gray squirrels have adapted to the urban too of course.

In a U. of I. study initiated in 1997 by Wendy Jackson and Joel Brown, citizen-science reports have indicated that: 
Fox squirrels were more likely to be observed in the western and especially southwestern suburbs. There were 27 zip codes where only gray squirrels were recorded, compared to only two zip codes where only fox squirrels were recorded (60104 in the village of Bellwood and 60402 in the village of Berwyn). There were 85 zip codes for which both fox and gray squirrels were recorded.

One significant finding of that study was that fox squirrel abundance was associated with high populations of domestic cats. The smaller gray squirrel is more susceptible to predation.

Our study provides support for the idea that fox and gray squirrel coexistence is facilitated by a trade-off between managing the cost of predation and foraging efficiency, gray squirrels out-competing fox squirrels in areas of high food and low predator (or pet) density.

Decreasing numbers of fox sq
uirrels have made them a species of concern in the states of New York, North Carolina, South Carolina, and Alabama. 

But this is Illinois. Since they're widespread in lots of suburban zip codes, should our conservation thinking just ignore fox squirrels? But many bird species (for example the red-headed woodpecker and the barn owl) were long considered common inhabitants of yards and farms … but later became conservation priorities when those habitats stopped working for them. Too much pesticide? Changing tastes in landscaping? In contrast to urban landscapes, survival in nature seems more secure for both the species and the ecosystem. And is it possible that the oak communities would benefit in various ways from the return of this classic species?

Ecosystems are difficult to study. The first ecological study of Somme Woods was in conducted in 1908. Then, after a long pause, dedicated researchers at the Sommes have made strides in the study of plant communities, rare plants, woodland breeding birds, seed banks, and much more. Creative approaches (both pure science and applied) are much needed to help with management questions that need answers now. 

It's interesting to consider the status of fox squirrels of southeastern United States as described in this NatureServe report:

The greatest threat to fox squirrel populations is in the southeastern U.S., where distribution and abundance have been reduced by loss of mature forest habitat. The widely spaced trees typical of mature longleaf pine-turkey oak forest upon which populations in the southeastern U.S. depend favor the squirrel's large size, running proficiency, and tendency to escape along the ground. The very open, parklike forest stands resulting from frequent fires produce better crops of pine cones and mast. However, the longleaf pine ecosystem, which once comprised some 70 million hectares across the southeastern Coastal Plain, is today represented by only about 2% of its original range. Survival of the fox squirrel in the Southeast is intimately tied to the fortunes of this declining ecosystem. 

Only 2%? That's low, but Illinois' surviving high-quality savannas comprise less than 1/100th of 1% of the original, and the more common degraded ones are losing health and sustainability fast. 
It would be tempting to hypothesize that fox squirrels might facilitate the restoration of our badly challenged oak woodland and savanna communities. What added information would we need? 

They're relatively easy to study. Fox and gray squirrels - like humans - are unusual among mammals in being out and active in the daytime, much easier for citizen-scientists to observe than coyotes, foxes, deer, weasels, raccoons, and, for that matter, flying squirrels, which too are nocturnal. Can anyone help us understand whether more of their foxy handsomeness would be a good addition to the growing biodiversity of Somme's savannas and woodlands?

References
Study comparing gray and fox squirrels in the Chicago area:


Acknowledgements
The opening photo is from our friend Michael Jeffords in Outdoor Illinois Journal.
Photo of fox squirrel eating a flower is from Welcome Wildlife. 
Final photo is from Wikipedia, a good service that deserves our support.
Proofing and edits by Eriko Kojima. 

Thursday, October 3, 2024

Hypothesis: Good Restoration for Plants will in time mean Good Restoration for Birds.

When restoration began in Somme Woods, the ground under the trees was bare. This preserve supported few birds, butterflies, snakes, or animals of any kind. 

Our hypothesis from the beginning was that restoring health and natural diversity to the plant community would also be good for the whole ecosystem, including its animals. 

But that was a hypothesis. Little such experiment has been done. Less has been tested scientifically. 

We spend most of our time as stewards working to bring back the herbs (herbaceous plants: grasses and "forbs") ("forbs" is a technical name for wildflowers). In a few mere decades we could show that basic restoration techniques could, at least for the foreseeable future, conserve large numbers of rare or uncommon plant species and gene pools that would otherwise have been lost. Most of plant diversity, even in woodlands, is among the grasses, sedges, and forbs.

This post was inspired by the impressive abundance of migrating birds feeding down in the herbs on September 24, 2024. A brief study on one day proves little. But it encouraged me to hypothesize yet more.

This year I'd been noticing large numbers of warblers flitting among the uncommon asters, goldenrods, and grasses that now grace increasingly large areas of the Somme woodland fall understory. This seemed new. When the brush is first cut, there follow seasons of bare ground and then aggressive "weedy" forb species. In the past these "weed patches" had attracted migrating sparrows, to eat seeds, but not warblers.

Few people perhaps would notice these little insect-eating migrants. Even when I found time to study them with binoculars, they were largely obscured by vegetation, or moving so fast, flitting from flower to flower and stem to stem that I failed to identify most of them. But in a few minutes I counted twenty migrating warblers of five species, and they carried a message.  

The most abundant was the Nashville warbler with eleven individuals. Like many warblers, they're mostly coming from Canada and heading for Central America or the Caribbean or the Amazon to spend the winter.

Nashville Warbler
Second most common were the black-throated green warblers (4 individuals identified) and the western palm warblers (3 individuals) - two species which typically spend their migration hunting time in very different habitats.  
Black-throated Green Warbler
In the past I mostly remember seeing the black-throated green high in mature trees. But on this warm and pretty day, hungry for insect fuel to power their long flights, they seemed to be going where the food was. I saw none feeding up in the trees. They hovered in front of flowers or jumped from stem to stem. 

Western palm warblers spend their summers in open bogs and their migration in prairies, fields, and dunes. Here they were in the herb understory of the woods, where I also saw one yellow-rumped warbler.

The other migrating warbler I saw today was an ovenbird. These handsome stripey-breasted characters hunt mostly on the ground in mature forest under thick shrubs. Or herbs? I've wondered if they might even return to nest here, as the habitat improves.  
Ovenbird
The wildflowers and grasses these birds flitted among included elm-leaved goldenrod, Short's aster, wood reed, silky rye, and woodland thistle. I saw these birds mostly in areas of improving diversity and quality.

Summer nesting birds had responded more quickly. In summers, the birds we see feeding in the herbs include the indigo bunting, yellowthroat, blue-gray gnatcatcher, hummingbird, and bluebird. Actually the bluebird perches on a low tree branch and watches like a hawk, until it sees a tasty bug and plunges down into the herbs to catch it. Once I was surprised to see a pair of scarlet tanagers foraging from flower to grass to flower, feeding on insects, leaving their expected high-in-the-trees habitat behind. This is not a common site, but then neither is an oak woods with abundant summer flora. 

Also impressive in the breeding season are the flycatchers and woodpeckers. Dramatically more common than before restoration, the flycatchers we see (and hear) most often the great crested, the eastern pewee, and from time to time the kingbird, a flycatcher that nests across Waukegan Road in the savannas of Somme Prairie Grove, but finds food in the open areas of this woodland too. Flycatchers hunt from the trees, but the flying insects they feed on may mostly get their substance eating herbs. That's probably why there were few of them when this preserve was just trees.

Woodpeckers are actually close relatives of flycatchers, and they're a major Somme success story. It's easy to see the link in red-headed woodpeckers, which also often sally out from a perch to catch flying insects. They also eat the acorns and boring beetles that feed on wood. Long described as one of the fastest-declining birds on the continent, the red-headed was absent from the Sommes before restoration but now are represented by five or more breeding pairs every year. 
Red-headed woodpecker feeding young
The flicker is a woodpecker that mostly feeds on the ground. Eating insects living there, it was absent from Somme Woods when restoration started but now may be the most common summer woodpecker. 

The pileated woodpecker also feeds on the ground a surprising amount of the time. Often they tear apart rotting logs for the delicious treasures within. But they like room to fly and have come back to Somme only recently.
Pileated woodpecker

No habitat works for every bird. But restoring plant communities at Somme seems to work well for many species of conservation concern - including migrating fall warblers. More study of varying approaches to restoring habitats would help conservation prioritizing.  

***

If you might like to help Somme's fall seed gathering or winter brush cutting with bonfires, check the schedule here

For other Somme Woods bird posts, see
and 
and

A confirming report from National Audubon Society is at:

Acknowledgements

Mourning warbler photo from A-Z Animals
Red-headed woodpecker photo from Birds and Blooms
Pileated woodpecker photo from American Bird Conservancy
Other photo credits: All About Birds (Cornel Lab or Ornithology)

Thursday, September 5, 2024

Savanna Blazing Star - and How Science Works (sort of)

Unlike other blazing stars here, this one's flower heads are on stalks.


For 35 years the rare Savanna Blazing Star (Liatris scariosa) and its noble animal and plant associates have given us a wild ride at Somme Prairie Grove. We learned along the way. For starters, let’s take a peek into some of the bad-mannered backstory. 

 

Henry Alan Gleason, an Illinois farm boy, briefly became the cutting edge of ecology - before he was banished by academics who couldn’t tolerate new ideas. As compellingly presented by Jack White, Gleason made a great start. He produced “the first quantitative descriptions of vegetation of any kind recorded by any ecologist anywhere in the world.” So far so good. But he also questioned some principles that back then were considered sacrosanct – for example, that “succession” was always good … and fire always bad. 

 

In five articles published from 1917 to 1939, Gleason battled establishment science – and lost. Today most ecologists would largely agree with Gleason, but at the time, as White put it, “His colleagues shunned him. Not a single ecology text quoted and used Gleason’s ideas for thirty years.” Gleason quit ecology, got hired as a taxonomist at the New York Botanic Garden, and put his mind to assembling the monumental New Britton and Brown Illustrated Flora of Northeastern United States and Adjacent Canada (1952).

 

His book deserves credit for the rehabilitation of the savanna blazing star. Just so you know, two warring books long provided authoritative catalogues and descriptions of the plant species of northeastern North America – Gleason’s book and Fernald’s. (See Endnote “What is a species?”) The traditionalist nature of botany is apparent in the very names of these two standard books. The first, by Merritt Lyndon Fernald, was entitled Gray’s Manual of Botany (1848). But Gray didn’t write it. Asa Gray (of Harvard) did write the first version, but it was later revised by others until, more than one hundred years later, the 1950 version which the title page admitted was “largely rewritten and expanded by” Fernald. The second book was initially written (1896) by Nathaniel Lord Britton and Addison Brown of the N.Y. Botanical Garden; its text was “entirely rewritten” by Gleason, but it’s still called The New Britton and Brown Illustrated Flora of Northeastern United States and Adjacent Canada (1952). 

 

I knew none of this, but I’d been inspired to contribute to conservation, and as this mission clearly needed help, I was eager to learn as much as I could. I bought a copy of Gleason’s flora – three-big-volumes – because I wanted the pictures. Gray is 1632 pages of mostly technical language, with no illustrations of most species. Gleason gives us 1732 bigger pages, with plenty of important technical language too, but also lots of pictures. 

 

As I worked to protect Nature Preserves, I learned to distinguish more and more wildflowers, grasses, and trees. I’d been finding one plant that puzzled me; in Gleason’s book it seemed to be New England blazing star (Liatris novae-angliae), a species not in Swink and Wilhelm’s highly-respected Plants of the Chicago Region (1979).

 

Swink and Wilhelm weren’t alone. It turned out that none of the Illinois plant books recognized the species I thought I was seeing. As my work grew in effectiveness and reputation, I increasingly had the ear of those great botanists Floyd Swink and Gerould Wilhelm. Though very busy people, they sometimes helped me with difficult plants. But in the case of what turned out to be Liatris scariosa, both experts encouraged me to forget it. Swink told me that there were already too many species, and we ought not to be burdening the flora with more divisions. He was being what botanists call “a lumper.” Wilhelm said that the Liatris genus was full of messy hybrids, and looking deeper into this one wasn’t worth the time. Neither Swink nor Wilhelm wanted to hear about Gleason. They said they preferred Fernald.  

 

Yet, for some reason, this beautiful plant rankled my peace. I kept finding different ways to ask them about it. After all, Gleason’s book had those pictures. And a breakthrough emerged as part of my efforts to get scientists and conservationists to pay attention to the tallgrass savanna (see endnote Savanna. It was a nearly lost ecosystem – nearly gone on the ground and equally gone from the mind. It was not among the habitats discussed in the 1979 Plants of the Chicago Region. The Illinois Natural Areas Inventory had looked for it but found only two questionable acres of Grade B and no Grade A at all. I’d been claiming that we had the wrong search image, that we could learn to recognize remnants, and we could bring the savanna back. 

 

Wilhelm, bless his heart, finally listened when I told him that I was finding these plants only in savanna remnants – and indeed remnants that were fast being lost to brush and shade. He generously said, “Well, okay. It will be a lot of work. But if you can bring me examples, preserved on herbarium sheets, from a number of populations, with lists of associated species, I’ll study it and make a determination.” 

When the dust cleared, we had a formal scientific paper authored by Marlin Bowles, Wilhelm, and me. Liatris scariosa var. Nieuwlandii was now the “Savanna Blazing Star” and officially placed on the Illinois Endangered and Threatened Species list. (See more details in Endnote: Swink, Fernald, and Gleason.)

 

Okay, recognizing the plant’s existence was a good step. But what about its conservation? The populations I found were in open woods, rapidly becoming darker in the absence of fire. If some people still wanted to argue about the proper naming of this thing, we don’t much care. Any name is fine. What was really needed was to save it and the rest of its vanishing habitats and associated species of plants and animals in tallgrass savannas and open woodlands. 

 

Before long, a few sites where it occurred got better management. Others were lost to brush. We also wanted to learn more about it through restoration, and we put its seeds into the North Branch Restoration Project seed mixes. Somewhere in our records is preserved our first mention of planting its seed. In the wild, blazing stars take at least a few years to get robust enough to flower. We first recorded flowering plants at Somme Prairie Grove in 1992. There were six. We found nine in 1995. In 1998 there were six again, but then numbers started to rise. Fourteen in 2000. Eighty in 2006. One hundred eighty-nine in 2010.

 

Heedless of where we planted them, this species has seeds that blow in the wind, and plants spread on their own. The 2016 map showed sub-populations of five or more plants in eleven places. These sub-pop numbers varied widely from year to year. At one point we realized that the savanna blazing star is truly happy only in the first year following a burn. This is a highly fire-adapted plant. The graph below shows the burn/no-burn alternation for a sub-pop that benefitted from fire preceding the 2004 growing season and every second year thereafter through 2019.

Numbers of flowering plants of savanna blazing star in Sub-pop B from 2004 to 2019

Another discovery came only recently. Although we recorded 624 savanna blazing star plants in 2023 and new populations continued to show up where none had been planted, we wondered why some formerly thriving sub-pops had gradually faded out and were now gone. In some cases the plants emerged where the savanna seed mix had been planted in spots where enough brush had been cut to allow a fully vigorous growth of the taller prairie grasses. Here the savanna blazing star couldn’t compete once the grasses had fully taken hold. It seems only able to compete where semi-shade (or other factors?) limit the vigor of those grasses. But then in some of the shadier areas, woodland sunflower had taken over, and our Liatris friend also couldn’t compete with it. This was a Goldilocks plant, as are so many. They can compete successfully with all other plant species, but only in particular circumstances. 

 

Another surprise came from one area where we provided this plant with temporary artificial care. Back when we had first noticed some sub-pops fading out, apparently because of competition from temporary aggressive species, we wanted to be sure we’d have an ongoing seed source for a while. Thus we chose one of the fastest growing sub-pops and annually scythed down the aggressive plants, starting this approach at least by 2006 and continuing to this day. This experience led to a whole new restoration approach for most highest-quality, now expanded to many areas (to be discussed in a upcoming post on the concept of “lo-pro”). 

 

The area being discussed here, called Sub-pop M, from which we seemed to learn quite a bit, had no trees overhead or to the south but did have trees shading it for part of the day on both the east and west. Warm-season grasses including big bluestem, dropseed, and Indian grass are scattered throughout but mostly sparse and young. We expect them to increase. 

For now it’s sufficient to know that this small area, artificially maintained at first for assured savanna blazing star seed production, settled down into something good we hadn’t seen elsewhere. So we began scything aggressive species in a variety of habitats nearby. And bit by bit, our blazing stars began showing up in those semi-shaded, scythed areas. For many years all savanna blazing stars in this part of the preserve were only in that one little scythed area, 40 feet by 15 feet (or 12 meters by 5 meters) . In 2024 that long-scythed area had 87 blooming savanna blazing stars, and in the surrounding areas, scythed just the last few years and where none had been prior to scything, we counted 23 blooming plants. 

 

But that was just a part of the discovery. In the long-scythed area, many other high-quality plants were joining them. We were on to something. Following scything, and with increasing competition from quality species, the formerly aggressive species seemed to be fading back towards a play-well-with-others status. Little scything was needed in this area in 2024. We’ll publish more posts on this approach when we can. 

 

The photo below is not a classic “beautiful image” with  vast swaths of color or precious close-ups. But it has the beauty of health, diversity, and increasing success.

With aggressive species scythed selectively for nearly two decades, the ground here is dense with savanna blazing star, prairie obedient plant, big bluestem, cream gentian, gray goldenrod, wood betony, sweet black-eyed Susan, tall coreopsis, rattlesnake master, Penn sedge, dropseed grass, wide-leaved panic grass, azure aster, Short’s aster, and so many others. Ten feet away is unscythed dense tall goldenrod and woodland sunflower, with bare ground beneath. 

 

The deepest pleasures of this work come from the actions - some wise and mistaken - that end up producing trial-and-error-with-occasional-success learning and can lead to the recovery of healthy and happy biodiversity. 


Endnotes

 

Endnote: How to distinguish savanna blazing star from rough blazing star, for sure.


Usually in the Chicago area the savanna blazing star is easily separated from all others by the stalks that hold its flower heads away from the main stem. Rough blazing star normally does not have those stalks. 

Savanna blazing star, showing flower heads on long stalks.

But an especially good feature that may be more consistent is the character of the bracts at the base of the flower heads (technically, "phyllaries"). Savanna blazing stars have bracts that look like plain, tiny green leaves. In the rough blazing star (the only one likely to be confused with the savanna) those bracts look like the bases of iceberg lettuce leaves: they're puckered or curled with whitish or translucent parts.   

The green, leafy bracts of the savanna blazing star.


The bracts of the rough blazing star are puckered and crisped. 

Other features that may catch the eye from a distance include flower heads that are typically larger and more deeply purple in the savanna blazing star. This species also starts blooming later in the season.


According to Wilhelm and Rericha, the rough starts to bloom on July 22 while the savanna waits until August 26.


It you might get a kick out of the technical language that distinguishes these two species in Wilhelm and Rericha' key, here it is:


Rough blazing star: Middle phyllaries bullate, glabrous abaxially; distal phyllaries with broad, uneven, irregularly lacerate, eciliate scarious margins; heads all sessile or on peduncles shorter than the involucres.  


Savanna blazing star: Middle phyllaries non-bullate, glabrous, hirsutulous or cinereous abaxially; distal phyllaries uniformly narrow with entire, slightly erose or ciliate scarious margins; heads sessile to very often on peduncles as long as or longer than the involucres.


On the other hand, I can usually tell which is which with a quick glance from many feet or meters away. You need the technical language only to be sure, when learning the gestalt, or in the case of individuals that have quirky mixes of characteristics. In those cases you can, like most botanists, ignore them. 


Endnote: What is a species?  

 

The word “species” had been defined as “a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding.” But we now know that many species, especially under stressful conditions, breed across species lines quite shamelessly.

 

“Endangered Species” is a status that brings funding and legal protections – determined by legislatures and votes. But what is and is not a species is determined by scientists. At one time, people would turn to Gleason’s or Fernald’s book to determine what was and was not a species. But we learn more, it gets complicated, and our expertise changes. For fuller definitions and problems on “species”, see the discussion in Wikipedia.

 

Biodiversity conservation focuses at three levels: the gene, the species, and the ecosystem. Species are the easiest of the three to study, but the least important. If a species survives but most of its genetic alleles are lost, then most of that species is also lost, although few would know or understand. Most species and most of their genetics are conserved only in living, changing ecosystems

 

As Lynn Margulis, Merlin Sheldrake, and others have pointed out, we can make it harder to understand ecosystems when we retreat too far into specializations. Science needs better ecosystem science that deals with wholes. At one point Sheldrake was asked whether universities should recognize his specialty, fungi, with full scale departments, on a par with botany and zoology. His response was basicly, God, no! Not more divisions!” It's time to recognize that “studying and saving healthy  ecosystems” and overall “biodiversity conservation” are vastly more important than just “saving endangered species,” as valuable and important as that is. As important and underfunded as specialists are, wholistic generalists are supported even less. Conservation needs both. 

 

When Illinois botanists accepted the savanna blazing star as a species, they also found some populations in the western part of the state. 

At some point Liatris scariosa was removed from the Illinois Endangered and Threatened list, perhaps because of additional populations found, or because conservationists have successfully made its populations more secure; the Endangered Species Board doesn't tell us.  


Endnote: Swink, Fernald, and Gleason 

 

It's a huge amount of work to wrestle with hundreds of species and figure out which ones deserve to be recognized as "good" species and which do not. To his credit, Fernald seems to discuss this plant under L. ligulistylis (his Liatris "no.12") as follows: 

The anomalous X L. Nieuwlandii... considered by Gaiser, from cytological evidence, a hybrid of n. 12 with a second but unidentified species (although occurring almost wholly outside the range of the western inferred parent, i.e. from Mich. and Wisc. so. into OI., Ind., Ill, and Mo., and flowering one to two months later) ... needs further consideration.


In their good wrestling with this "element" in Swink and Wilhelm's 1979 Plants of the Chicago Region, they included the following observation under “Liatris aspera ROUGH BLAZING STAR”:

 “There is a very interesting element which occurs in Cook County, and probably elsewhere in our area, that probably represents a hybrid between L. aspera and some other species; some of these have been named L. X nieuwlandii and L. X sphaeroidea. Some have been referred to L. ligulistylis, although Fernald restricts that species to an area to the north and west of us. Furthermore, Gleason gives the commonest habitat as damp low places for L. ligulistylis, whereas our plants seem invariably to be found in dry clay areas with a former history of cultivation or other disturbance.” 

 

But that's not the only clue found in Gleason. It was his description and drawing of Liatris novae-angliae that had teased me into wondering if that was the plant I was finding in the rare savanna remnants. Swink didn't mention L, novae-angliae, despite the fact that Illinois is within its range according to Gleason, who expressed that range in abbreviations as follows: “s. Me. to n. Mich, s. to Pa, W. Va, Mo. and Ark.” Thus, if you draw a line (for the western boundary of this plant’s range) from northern Michigan to Missouri, Illinois is well within it.   


I was not the first Illinoian to notice. In 1846, S.B. Mead, a country doctor, published a list of plants and habitats mostly from west central Illinois, and he identified Liatris scariosa as a species of the barrens, a name sometimes used back then for the savanna. Mead was a sufficiently accomplished botanist that a number of species now have the specific name "meadii" - in his honor. When I referenced that list and this plant in support of the idea that the savanna was as real as prairies and forests and equally worthy of conservation, some rebutted by questioning whether the plants Mead referred to as scariosa were the same as the ones I was finding. I looked for confirming herbarium specimens but failed to find any. Then by extraordinary luck I was invited to give a talk at the Royal Botanic Garden at Kew near London. There, in one of the world's great herbariums, I found Liatris specimens collected by Mead. On the sheet to which he had fastened his specimen of rough blazing star, Liatris aspera, he wrote the word "prairies". On his specimen of Liatris scariosa, which sure looked like the ones I was was finding, he wrote the word "barrens." A photocopy of that herbarium sheet now is part of the Morton Arboretum herbarium. 

 

Thus, in the 1994 edition of Plants of the Chicago Region Swink and Wilhelm bring us up to date on this species:

 

Liatris scariosa (l.) Willd. var nieuwlandii Lunell SAVANNA BLAZING STAR … According to Bowles, Wilhelm, & Packard (1988), who discuss its taxonomy, distribution, and ecology, this species is prevailingly a plant of savannas on the Tinley and Valparaiso morainic systems in the Chicago region, growing only on the Morely-Markham-Ashkum silt loam soil catena. … Single Cook and Will county sites containing this species have been managed by prescribed burns. All other Illinois populations are very small and appear vulnerable even to minimal disturbances. Quercus macrocarpa is the characteristic overstory tree ... Forty-one herbaceous species have been recorded withing one meter of Savanna Blazing Star, the more frequent and characteristic being … Arenaria lateriflora, … Lathyrus venosus, Polygala senega, … Taenidia intergerrima, Thaspium trifoliatum.” 

 

I wasn't asked to comment on that draft, which I don't at all intend to quibble with. Swink and Wilhelm's noble 921-page book would never have been finished if the authors stopped to check with everyone on everything. But in retrospect I might suggest that “disturbance” was less the threat to the surviving populations than lack of fire. Indeed, much savanna and woodland biodiversity had to date been saved from the deadly dark only by various disturbances; cutting some trees down or some amount of grazing had allowed some species to survive. I might have added that I had also found this plant under white oaks (not just bur). And perhaps it's worth pointing out that there was something special about five of the forty-one ‘prairie’ and ‘woodland’ species that I’d found growing within one meter of the savanna blazing star. Those species are among the ones that seem to be indicators for the black-soil savanna ecosystem, which was only beginning to be recognized by ecologists as a distinctive community type which has some characteristic species.  


Those five, with their common names, are: 

Arenaria (or Moehringia) lateriflora - grove sandwort

Lathyrus venosus - veiny pea

Polygala senega (or Senega officinalis) - Seneca snakeroot

Taenidia intergerrima - yellow pimpernel

Thaspium trifoliatum - meadow parsnip. 


So how well is the species status of Liatris scariosa now established? Internet searches seem to indicate that it's documented well for many states and regions. 

On the national level, the U.S. Forest Service has a good report indicating that this species, which they describe as relatively uncommon everywhere, includes three varieties:
Liatris scariosa var. Nieuwlandii. "Savanna blazing star." Midwest United States.
Liatris scariosa var. novae angliae. "New England blazing star." Northeastern United States. 
Liatris scariosa var. scariosa. "Devil's bite" Southeastern United States.

Though often very helpful, the U.S. Department of Agriculture, Natural Resources Conservation Service's entry for this species in its PLANTS Database leads with
 a photo that does not seem to have the characteristics by which we identify the savanna blazing star. It maps all three varieties but shows Nieuwlandii - which it calls Nieuwland's blazing star - reaching all the way from Missouri and Illinois into New York and Connecticut. The maps in the PLANTS Database show all three varieties in Pennsylvania and New Jersey. Are all three really there? Interbreeding or not interbreeding? Or is there just not clear information from those states? 

Endnote: What is a Savanna?

 

This is a more difficult question than you might think - especially if the answer is to be interesting enough to read.

 

This blog has posts called What is a Grade A Prairie? and What is a Grade A Woodland? The answers to those questions seemed basically straightforward.

 

But the word savanna has an especially troubled history. It was little used in the Midwest before John Curtis’ seminal book, The Vegetation of Wisconsin, in which he pointed out that the savanna had been the most common vegetation type in the southern half of the state but by then was largely gone. He used the pioneer term Oak Openings for that major savanna type.

 

The Illinois Natural Areas Inventory, which followed Curtis extensively, defined the “Savanna,” and “Sand Savanna,” and "Barrens" as the principal types. In efforts to explain all this to the public, it has been awkward to explain that the term “Savanna” does not include the “Sand Savanna.” I kind of wish it had been called the Black-soil Savanna or the Tallgrass Savanna or such. Trying to clarify, others have renamed this community “Fine Textured Soil Savanna “ and other names perfectly hopeless to become part of common speech.

 

An additional confusion came from the Illinois Natural Areas Inventory's attempt to solve the “missing piece” problem. They understandably decided to use the word savanna for the ecologically wide gradient between the treeless prairie and the dense forest, so their savanna has a tree canopy of up to 80%. That turned out to be too wide, so subsequent work defined an additional community type, the oak woodland. 

 

There was a basic challenge in reaching the definitions and resulting ecological descriptions that are needed to guide conservation action. No high-quality examples of tallgrass savanna survived. Thus there was little point in being as detailed as was done for the prairie and forest, where there were high-quality models to learn from. The only real way now to understand the tallgrass savanna and oak woodland would be to see if good management could restore high quality.

 

An additional challenge arising in the context of this post is that we named the savanna blazing star in the context of the Illinois Natural Areas Inventory definition of the savanna, as it was back then, that is up to 80% canopy. It could be that, as we continue to learn, we’ll find that the savanna blazing star should have been called the woodland blazing star. Or it could be that this species will thrive in both savannas and woodlands.

 

As for what a savanna is, if you’ve been patiently waiting for an attempt:


The tallgrass or black-soil savanna is a community with substantial amounts of both trees and tall grasses, best defined by its dominant and characteristic species – especially those that most depend on it. The principal trees in northeastern Illinois are bur oaks in drier areas and swamp white oaks in wetter areas. In other parts of Illinois, other oak species may predominate. The typical graminoids are the “prairie grasses” plus many sedges, wood reed (Cinna), and rye (especially Elymus virginicus, riparius, and Canadense). 

 

Perhaps more significant for recognizing quality are the less dominant but more characteristic species. Among the plants these include veiny pea, purple milkweed, cream gentian, bearded wheatgrass, and Maryland snakeroot. Among the birds, characteristic species include the ruby-throated hummingbird, black-billed cuckoo, eastern kingbird, orchard oriole, sparrow hawk, and Cooper’s hawk. Many amphibians, reptiles, invertebrates, and fungi also deserve to be on this list. To be sure about all this we need enough large high-quality sites and experts to study them. The animals will likely play a major role in helping the best sites to recover; without them we’re not looking at a real and sustainable ecological community.


"Barrens" and "glades" are related communities which support some of the same species. In early writings, these terms along with prairie and savanna were often used interchangeably. As they are defined today, barrens occur on very poor soils, which limits what plants can grow there. Glades and dolomite prairies occur where shallow soil, often just a few inches of it, lies on bedrock. 


References


The extensive references to how this new Illinois species was verified are summarized in:


Bowles, M.L., G. Wilhelm, and S. Packard. 1988. The Illinois Status of Liatris scariosa (L.) Willd. var nieuwlandii Lunell. A New Threatened Species for Illinois. Erigenia. Illinois Native Plant Society. Number 10. Pages 1- 26.


Acknowledgements


Hundreds of smart, dedicated people did the work on which this report is based.


Eriko Kojima caught an atrocious number of typos and made helpful editorial suggestions. 

Sunday, August 4, 2024

A Plea to help the Kirtland's Snake

by Floyd Catchpole

Floyd is a long-term conservationist who recently retired from Will FPD.

Kirtland’s Snake threatened by Will County Forest Preserve

In October 2022, the Forest Preserve District of Will County (FPDWC), Illinois learned they had a previously unknown population of Kirtland’s Snake in Plum Valley preserve.  Kirtland’s Snake is a globally imperiled (G2) snake that is listed as threatened or endangered in all five states where it still occurs.  However, instead of rushing to protect and improve the habitat for the Kirtland’s Snake, the FPDWC submitted an incidental take permit (no. 276) from the Illinois Department of Natural Resources so they can build a 10-foot-wide asphalt trail with three -foot-wide mowed shoulders through the Kirtland’s habitat.  The Illinois Department of Natural Resources is taking comments on this application until September 2.  

Kirtland's Snake
Internet photo courtesy of A-Z Animals

Known as one of the harder snakes to find, it wasn’t until the second (and final) year of looking that the Illinois Natural History Survey found three Kirtland Snakes along the alignment for the proposed trail.  The draft conservation plan (Plan) submitted by the FPDWC indicates that it expects to take (aka kill) three Kirtland’s Snakes, or the entire newly found population.  Of course, there may well be more than three Kirtland’s at Plum Valley, but whatever the number they will likely all die.  NatureServe states that “Restoration potential depends upon the degree of habitat alteration. Permanent alterations such as pavement prevent restoration.” The FPDWC plans to pave the existing gravel chip trail and the entirety of the planned trail.  Please email DNR.ITACoordinator@Illinois.gov with your comments.

A 10-foot-wide trail (paved or gravel) creates the risk that bicycles may run over Kirtland’s Snakes, or that people will collect the attractive snakes as they warm themselves on the trail.  Additionally, changes in water levels associated with the creation of the trail that may harm crayfish populations and thus Kirtland’s Snakes. 

What could be done to protect the Kirtland’s Snake? Leave the portion of the existing trail that is close to the Kirtland’s population with a gravel surface.  Connect the new alignment to the existing trail far away from the Kirtland’s Snake population.  Reroute the new alignment far away from Kirtland’s Snake habitat.  Conduct multiyear surveys for Kirtland’s Snake throughout all of Plum Valley Preserve prior to construction to determine if the Kirtland’s Snake occurs on more of the preserve.  Allocate significant conservation dollars to enhancing habitat at Plum Valley Preserve. Please submit your comments by email to DNR.ITACoordinator@Illinois.gov

What is the Plan proposing to protect the Kirtland’s Snake?  The FPDWC has agreed to post information about the presence of snakes (without mentioning Kirtland’s to reduce collection pressures) in the trailhead kiosk.  The FPDWC will minimize the width of the construction zone as much as possible while maintaining safety. The FPDWC and contractors will look for Kirtland’s Snake on construction days and contact IDNR for their safe removal. The FPDWC will search for Kirtland’s Snake two and five years after completion of construction. The FPDWC will perform normal soil erosion and sedimentation measures.  And FPDWC will spend $20,000 to improve Kirtland habitat at Plum Valley. Please email DNR.ITACoordinator@Illinois.gov with your comments.

Additional shortfalls in the Plan

Kirtland Snake mortality from vehicles, (NatureServe) including bicycles and mowers are well documented (PARC pgs 16-20) and the proposed trail alignment goes through the habitat where the Kirtland’s Snakes occur.  Kirtland’s snakes are known to bask on roads year-round when conditions are right and rare and attractive snakes like the Kirtland’s may be collected for the pet trade when seen warming on the black asphalt trail. 

The Plan is required to indicate that the proposed taking will not reduce the likelihood of the survival of Kirtland’s Snake in Illinois.  But it simply states that there are other populations of Kirtland’s Snake in the state, so this project will not reduce the likelihood of the survival of the species. The Illinois Natural History Survey (INHS) website states that Kirtland’s Snake is now known from only four of Illinois’ 102 counties; hardly a reassuring fact.  By the FPDWC’s logic, populations could be picked off one at a time until there was only one location left in the state.  Please email DNR.ITACoordinator@Illinois.gov with your comments.

This snake is harmless, gentle, valuable to the ecosystem, and gone from much of its former range (gray in the map above). Current known occurrences are in red. 
Map courtesy of ResearchGate.

The conservation plan is required to describe alternative actions that would not harm the Kirtland’s Snake (IDNR), but the FPDWC interpreted this to mean that they only had to say they considered and rejected undescribed alternative routes in a field meeting with their Contractors and ComEd (whose property the trail might cross in one spot).  The undescribed routes were rejected to avoid: high quality floral assemblages; high-quality trees; wetlands; forested areas and crossing the creek where it is wider with an associated wetland.  

The lack of described alternatives means none of the above statements can be verified or considered.  No description is provided of “high-quality” wetlands and trees to allow consideration of whether they are of such extraordinary quality that a globally imperiled and state-listed snake population should be sacrificed for them.  The statement that creek impacts are reduced by the chosen alternative is completely unsupported, unless we are to accept the implied higher cost of a wider bridge as reason to sacrifice this population.  There is no description of alternative creek crossings, so no judgement can be made.  

The Plan is required to describe a “no action” alternative, but merely states that it rejects the no action alternative, since it would not connect the trails.

The Plan states that snakes, turtles, and salamanders generally abandon areas of construction.  NatureServe states that “Disturbance of the soil when Kirtland’s snakes are underground may cause injury or mortality of individuals.” And Kirtland’s Snakes are known to spend a lot of time underground in crayfish burrows, so changes in water levels, soil compression and siltation from asphalt trail construction may kill snakes and reduce or eliminate crayfish and thus the Kirtland’s Snake. 

References

INDR. August 2024. Conservation Plan Template. https://naturalheritage.illinois.gov/speciesconservation/applying-for-an-incidental-take-authorization.html

INHS. Kirtland’s Snake. https://herpetology.inhs.illinois.edu/species-lists/ilspecies/kirtlands-snake/. Illinois Natural History Survey website.

NatureServe website. August 2024. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.105161/Clonophis_kirtlandii

PARC.  Habitat Management Guidelines for Amphibians and Reptiles of the Midwestern United States. Technical Publication HMG-1 2nd edition. 

Plan. July 2024.  Draft Conservation Plan for the Incidental taking of the State Endangered Kirtland’s Snake (Clonophis kirtlandii) and the Smooth Green Snake (Opheodrys vernalis). Forest Preserve District of Will County. https://naturalheritage.illinois.gov/content/dam/soi/en/web/naturalheritage/permits/documents/ita-conservation-plans/conservation-plans/276-cp.pdf

PS from Floyd:

If you are concerned about letting people know about the rare species, know that the location of the preserve where the Kirtland's occurs has been posted in the FPDWC's public announcement.

The USF&WS has announced that they will consider Kirtland's Snake for listing as a federally endangered species. https://biologicaldiversity.org/w/news/press-releases/midwests-imperiled-kirtlands-snake-gets-second-chance-at-endangered-species-act-protection-2024-07-01/

Saturday, July 20, 2024

Wet-Mesic Prairie: increasingly Doomed? or time for a Rebirth?

By Stephen Packard, Christos Economou, and Eriko Kojima

Wet-mesic prairie may have been one of Illinois’ commonest ecosystems. But high-quality remnants, now even rarer than for mesic prairie, seem close to gone. 

 

We’ve often wondered, are wetter prairies inherently less diverse, as some have claimed? It’s certainly a possibility. The Somme Team for decades has tried to visit and learn from all black-soil prairie types: wet, wet-mesic, mesic, dry mesic, and dry. But the high-quality prairies we found all seemed to be mesic or drier. Most of the wetter grassland areas we look at seem to be dominated by a small handful of clonal species. On the other hand, we do sometimes find small wetter spots in mesic prairies with diversity that rivals mesic prairie. (See Endnote 1.)

 

All natural areas are subject to degradation. But wet-mesic prairies face special, subtly invisible destructive forces. The bulldozer and plow are quick and dramatic. But in time the wetter prairies are destroyed also by the drainage ditch, the dam, sedimentation, and the "boom and bust" hydrology that comes from paving the watershed. When we recently asked a respected ecologist about the highest-quality wet-mesic sites in Wisconsin, he gave a site name and a glowing report but seemed to be speaking in the subjunctive. When we asked how it was doing now, his face darkened. He said it had been badly degraded by flooding.

 

On our home turf, the Somme Team in recent years has been looking a bit harder at some wet-mesic prairie areas that have been long “under restoration” by us. But really, we had more or less abandoned them except for burning as a part of the whole, though often they were too wet and the fires largely skipped them. In any case, early on, the mesic areas had motivated us to focus on them as they recovered and improved so much faster ... and then the mesic savannas captured our attention.  


But we've been increasingly troubled by the plight of our wetter areas. They had fewer species and less diversity. Did the dense “thuggish” species merely indicate poor ecological health, or were they hindering recovery? 


The dense shrubs and aggressive species could well be temporary, as in early stages of the restoration of degraded mesic prairies – eventually replaced by a diversity of rarer species of high conservation concern. Interested younger leaders helped our team to decide that our orphan wetter prairie patches deserved better help. So we got started.

Planting plugs of high-quality wetland species: how successful a solution might that be?
Christos (right) has advocated for more of it at Somme.
We think; we hypothesize; we test; and we revise approaches.

We considered changes in seed mixes. We started burning more often. We put more effort into controlling shrubs and “thugs”, monitoring results, and studying for clues.

 

We also wondered if there might be key missing elements of wetland diversity that might help recovery. We pored over species and associates lists, hoping for insights. The list below, from Wilhelm & Rericha (W&R) consists of twenty-three “characteristic species of wet to wet-mesic prairies” on “fine-textured soils” (as distinguished from lists of sand or gravel prairie species). 


The "C" column gives coefficients of conservatismThe "W" column gives wetness coefficients which range from -5 to +5. The lower the number, the wetter the habitat. 


Characteristic Species of Wet and Wet-mesic Black Soil Prairies of the Chicago Region

                

Scientific Name

C

W

Common Name

Asclepias incarnata

3

-2

swamp milkweed

Asclepias sullivantii

8

0

prairie milkweed

Calamagrostis canadensis

6

-2

blue joint grass

Carex buxbaumii

10

-2

dark-scaled sedge

Carex stricta

5

-2

common tussock sedge

Carex tetanica

7

-1

common stiff sedge

Eleocharis elliptica

10

-2

golden-seeded spikerush

Helenium autumnale

5

-1

sneezeweed

Helianthus grosseserratus

4

0

sawtooth sunflower

Hierochloe hirta

10

-2

sweet grass

Lilium michiganense

8

-1

Michigan lily

Lythrum alatum

7

-2

winged loosestrife

Oligoneuron riddellii

8

-2

Riddell’s goldenrod

Onoclea sensibilis

5

-2

sensitive fern

Phlox glaberrima var. interior

9

-2

marsh phlox

Platanthera leucophaea

10

-1

eastern prairie fringed orchid

Pycnanthemum virginianum

5

-1

common mountain mint

Silphium terebinthinaceum

5

0

prairie dock

Sorghastrum nutans

5

1

Indian grass

Spartina pectinata

4

-1

prairie cordgrass

Thelypteris palustris

7

-2

marsh shield fern

Veronicastrum virginicum

8

0

Culvers root

Zizia aurea

5

0

golden alexanders

 

Brief species lists had earlier been published by the Illinois Natural Areas Inventory (INAI). They treated the two wetter prairie types separately: 

 

Wet-mesic Prairie

Dominant plants:  Andropogon gerardi, Calamagrostis canadensis, Panicum virgatum, Sorghastrum nutans, Spartina pectinata.

Characteristic plants:  Lysimachia quadriflora, Oenothera pilosella, Phlox glaberrima, Senecio paupercaulus, Veronicastrum virginicum, Zizia aurea. 

 

Wet Prairie

Dominant plants:  Calamagrostis canadensis, Carex spp., Spartina pectinata.

Characteristic plants:  Cacalia tuberosa, Eupatorium perfoliatum, Iris virginica var. shrevei, Lythrum alatum, Sium suave. 

 

Two of the INAI's “dominant” wet-mesic species and three of the “characteristic” wet species don’t appear on the longer "characteristic" W&R list. All these lists are incomplete.

 

For Wisconsin, John Curtis lists 62 wet-mesic prairie species. Most of the Wisconsin prairies are in southern Wisconsin - closer to northeastern Illinois than are the central and southern Illinois prairies - so the Curtis list may be as useful for our Somme work as the Illinois statewide lists. 

 

Curtis found big bluestem to be a major component of wet-mesic prairie (in 40% of his quadrats). Other species that were frequent in his quadrat sampling, and that we had tended to think of as more mesic species, include little bluestem (29%), sky-blue aster (43%), bastard toadflax (30%), downy phlox (22%), and prairie dock (31%). Early on we had not put these species in our wet-mesic prairie restoration seed mixes. 

 

Why are we so interested in these lists and coefficients? They’re tools that helps us think: about goals, work priorities, monitoring, and evaluation. We want our ecosystem restoration efforts to be informed by as many facts and as much expertise as we can find. 

 

For restoration, over the decades, we’ve sought out and harvested seeds of as much of the full roster of mesic prairie, savanna, and woodland plants as we could find. Restoring high quality is not an initiative that plays out fast, but we seem to be on the road toward high-quality restoration of these mesic areas. 

 

We just haven’t given that level of attention to the wet-mesic. Perhaps now it’s time?

 

Two case studies are worth consideration. In both cases our failures are instructive.

 

Case study 1. The Pothole Peninsula

 

This area of about one-quarter acre has received special attention because for a time it harbored the world’s densest concentration of prairie white-fringed orchids (Platanthera leucophaea). It is bordered on three sides by a one-acre, u-shaped ephemeral pond and on the fourth side by prairie-like very open savanna. Its hydrology had long ago been disrupted by both a road that substantially blocks its original drainage and a small ditch that somewhat increases it. 

In the pond we successfully controlled the near monoculture of cat-tails. But disappointingly, so far as diversity is concerned, large parts of the pond are now near monocultures of iris, bluejoint grass, or bur-reed. The slightly visible open water areas (above) are where iris was recently set back by scything.

This pond had been heavily dominated by cat-tails with smaller amounts of purple loosestrife and reed canary grass. It was originally noted for two rare species – American slough grass (Beckmannia syzigachne) and Wolf’s spike rush (Eleocharis wolfii). Most seeded species "did not take." Tom Vanderpoel recommended planting some of the difficult-to-establish but most important species by plug instead of seed. That work has recently begun. 

The drier but still wet-mesic peninsula seemed for a while to respond well to our stewardship. When we began, it had a few species that suggested some surviving quality including sweet grass, smooth phlox, yellow star grass, and dark-scaled sedge. But most of the vegetation of the wet-mesic middle of the “peninsula” consisted of alien species that reflected decades of grazing. 

 

We broadcast seed of many missing species and cut brush and burned as often as we could. The area developed large populations of white-fringed orchids, small sundrops, and eared false foxglove. Because the orchid was a federal endangered species, we were nervous about the possibility that a radically changed "restored" species composition could drive out the orchid. This was probably a mistake, but it was our cautious thought. A better approach probably would have been to seed aggressively with conservative and fuel species so as to restore a sustainable, diverse turf. 

 

As it turned out, the burning reduced many alien and weedy species. Then aggressive natives including sawtooth sunflower and sneezeweed became so dense as to crowd out quality species from most of the area. When we controlled the new “thugs” – creeping thistle began to thrive, and today the area seems to hover between recovery and chaos. We focus elsewhere for a few years; the thugs come massively back;  we lop and scythe again. This area, unlike most of the site, is not improving in quality and sustainability. We believe it needs seed of missing species, especially grasses and other fuel species, and we have to try harder to get it burned regularly.  


With insufficient fire, the wet-mesic peninsula has decreased in quality. Recurring large patches of brush and aggressive forbs ("wildflowers") have shaded out its former old-field/remnant complexity. 

 

Case study 2. Northwest Prairie 

Original, remnant, degraded wet and wet-mesic prairie cover about two acres of northwestern Somme Prairie Grove (and were originally part of what is now Somme Prairie, on the other side of the railroad tracks). The original water flow from these two acres into the North Branch of the Chicago River was blocked by the railroad embankment and increased by ditching along (and a culvert under) the tracks. 

 

The remnant vegetation of these two acres when we started as stewards included all but three of the thirty-two characteristic or dominant wetter prairie species listed by W&R and INAI, but with the conservatives mostly in small numbers, mixed with aliens and brush. 


Compared to the preserve’s other grasslands, it’s been neglected. Though we’ve cut out most of the invading trees, large areas today are badly shaded by shrubs, river grape, sandbar willow, and aggressive forbs.


Most of Northwest Prairie looked like this, until recently - heavily shaded by native aggressive forbs and shrubs.

 

The biggest disappointment here had been the persistent poor quality of even the better areas. If high-quality vegetation had increased in some of these areas, we’d probably have been motivated to work more here.  

 

We probably made a mistake by withholding seed of major fuel species including big bluestem and Indian grass. Our working hypothesis in the early days was that these aggressive tall grasses were semi-thugs and that the smaller conservatives would restore best without them … and then the tall grasses would increase fast enough without help. That approach seemed to work well in mesic areas.

 

But Northwest Prairie rarely burned well, and lack of sufficient fuel was a likely part of the reason. In time we focused on insufficient burning as a likely major problem; in recent years we’ve added this area to those that are “burned annually” if possible, giving more chance that these wetter areas will actually burn on the day chosen. 


We’ve also increased our small brush control, begun scything herbaceous thugs in some areas, and increased seeding with a mix that does not omit the fuel species.


With increased burning and shrub control in recent years, original conservatives like prairie loosestrife (yellow), Culver's root (white), and smooth phlox (pink) increasingly thrive.

 

After decades of heavy brush and "thugs" just two years of better management in some areas has revealed resurgent quality. But, though lessened, the dominant vegetation remains thugs and brush.


Ox-eye daisy and black-eyed Susan add color to this railroad-side wet-mesic prairie. But large numbers of these "weedy" species show us areas most needing seed of quality conservatives.  


Ecologists who visit Somme Prairie Grove often express admiration for the restoration progress of some of our mesic and dry-mesic areas. They express no such enthusiasm for our wetter ones. With these new approaches and renewed determination to work harder, we're cautiously optimistic. We’ll report on how it goes after a few more years of effort, trial, and study.  

 

 

 Endnotes


Endnote 1. How rich were wet-mesic prairies? And what difference does it make?


Biodiversity conservation focuses on ecosystem types more than species, for a good reason. Although as shorthand we typically define ecosystem types by their plants, those plants are more important as indicators than for themselves. Plant species survive in interdependent networks of fungi, pollinators, herbivores, predators, both symbiotic and pathological bacteria, and countless more - literally countless - as science does not (yet?) have the ability to count them. Large parts of the smaller biota of ecosystems are poorly understood, unstudied, not even named. So we save them in named ecosystems.


Some of the species and relationships of wet-mesic prairies are absent or genetically different in mesic prairies and entirely distinct from those in dry prairies. Many such species survive only in high-quality remnants. If all our conservation is done in mesic and drier prairies, we lose much. A prejudice about wetter prairies being less diverse may be ill-founded.   


The INAI reported: "Wet-mesic prairie is much more diverse than wet prairie and nearly as diverse as mesic prairie."

 

As Prairie Botanist Dan Carter put it in comments on a draft of this post:  "Good wet-mesic prairie has the low stature typical of high-quality mesic prairie except for the flowering stalks of prairie dock and scattered stems (not dense stands) of sawtooth sunflower, sometimes some sparse cordgrass. Comandra abounds, sometimes wood betony (vs. marsh betony in wet prairie)." 


Dan further pointed out that, for remnant restoration, our challenge is to coax these systems away from degraded states where nutrient availability results in structure and composition derived excessively from light competition, where tall, rank species win. 


In contrast, sustainable, intact old-growth sods are structured by 1) competition for nutrients, largely tied up regardless of their amounts and 2) symbiosis, mutualismparasitism, fungal and animal consumers and predators, etc. A healthy conservative sod depends on synergies among all the diverse biota that make it up. Once degraded, to restore that interdependent balance is especially difficult on finer-textured soils where the advantages of aggressive species are less limited by seasonal drought as they are in drier prairie types.

 

Could we say the same about the original diversity of Wet Prairie and Sedge Meadow? The INAI reports: "Wet Prairie: Plant species diversity is lower than in other prairie communities," and "The sedge meadow is remarkably homogeneous in composition and structure," which seems to be a polite way of saying "species poor." Was that always true? Or have these wetter systems just been more quickly and thoroughly degraded by disruption of their hydrologies


Curtis and the INAI represented great steps forward for conservation, but there is now something of a consensus that they underestimated the value and uniqueness of savanna and oak woodland - in part because they had degraded faster than other community types. Might the same be true for wetter prairies? 


References


Conservation Research Institute. Floristic Quality Assessment. A wide variety of studies available for download. 


Curtis, John. The Vegetation of Wisconsin. 1959.


Taft, John and Gerould Wilhelm, Douglas Ladd, and Linda Masters. Floristic Quality Assessment for Vegetation in Illinois. Illinois Natural History Survey.  


White, John. Illinois Natural Areas Inventory – Technical Report. Ill. Dept. of Conservation. 1978.         


Wilhelm, Gerould and Laura Rericha. Flora of the Chicago Region. 2017.


Acknowledgements


This post benefitted from editing and comments by Dan Carter of The Prairie Enthusiasts. 


Cook County Forest Preserves ecologist Anna Braum deserves credit for improved planning and coordination as does fire boss Steve Ochab for increased and improved burning. 


Thanks to Illinois DNR's Melissa Grycan for additional information about high-quality wet-mesic prairies.


Grants from the Scholl Family Foundation and the Illinois Clean Energy Foundation have helped Forest Preserve volunteers and staff make progress in these areas.