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Tuesday, October 16, 2018

North Branch Seeds Seminar

This version of the post "Giving Rare Seeds a Good Start" was shortened 
and tailored for a North Branch Restoration Project seminar. 

Why plant seeds?

Why not just wait and see what comes up on its own? We’ve tried that many times, and the results have tended to be a temporary “weed patch” that did not become a sustainable ecosystem but just tall goldenrod, briars, and, eventually, buckthorn once again. Planting a diverse mix of (now rare) local ecotypes of grasses and wildflowers can restore the habitats of hundreds of species of plants and animals.  

Why is it important to plant seeds in the right place? 

Many species that we plant are now common and easy to gather in our restored areas. But some of our most important species are still rather rare – and harvesting them from the wild, as we do, diminishes the ecosystem they’re taken from. If we remove too much too often – we do damage. This is especially true of the seeds of some now-rare, formerly dominant conservative species. So we want them in our mixes, but we don’t want to waste them. 

Also, we don’t get as much seed as we need. Wetland plants won’t propagate on dry ground; species of full sun won’t grow in the shade. Our goal is to conserve rare biodiversity; we can’t ethically waste seed where it won’t grow.

Should we plant the same species in bare ground (where brush was cut) … compared to an area that just needs more diversity?

Many of the most important species won’t do well on bare ground, so we save them for “turf” mixes. 

How do I recognize where I should stop broadcasting the prairie seed mix and start doling out savanna seeds?

The first answer is that you’ll want to overlap those mixes a bit – as no one is so smart that they know for sure, and, indeed, the species mix naturally. 

The second answer is that it depends on how far apart and how big the trees are in your savanna. A rule of thumb: if full sun shines on a piece of ground for two thirds of the day or more, plant prairie seeds. But there’s much more on this, below. 

In restoring an oak woodland, should all the invading shade be removed before I plant my first seeds, or should the process be staged? 

Our knowledge of how to restore biodiverse woodlands is even more primitive than with prairies and savannas. Some approaches lead to an understory of briars, poison ivy, and other rank vegetation that seems to head in the opposite direction from quality. If you’re prepared to put in a lot of effort, open the canopy enough for oak reproduction … then plant diverse species for that level of sunlight, and let ecological processes take it from there. But other approaches may also show promise.  

Some Visuals That Might Help

Many restoration principles can be expressed simply, but recognizing how to apply them on the ground in a specific place is the real challenge. Don’t expect to be perfect at it. In fact, just go ahead and assume that you won’t be right all the time and in every detail. But thinking about the principles ought to help. And field exercises help the most. The visuals below were designed to help prepare for field exercises. 

Our seed mixes are called “Prairie,” “Savanna,” and “Woods.” That works well in the prairie and a uniformly shady woods, but in the savanna, probably the mixes should be called something like “Full Sun,” Part Sun,” and "Dappled Shade.” 

SIMPLIFIED DIAGRAM

The graphic above simplifies the decision by considering only the amount of sun. Most open savanna should be seeded with the “Prairie” mix. But immediately under and around and especially to the north of isolated large trees (considering how the sun’s rays slant at our latitude), plant the “Savanna” mix. In the darkest parts of the savanna, blend in some “Woods” mix. 

There is no “maple forest mix” on this map, because the North Branch had little of the maple/basswood or beech/ maple forest (and those fine natural communities are a good deal less threatened than oak communities, so there’s been less research on restoration techniques or conservation goals or priorities). The darkest community we’re considering in this exercise is oak woodland and oak forest, which have much brighter understories than a maple forest. 

Notice, above, that the seed mixes to be planted in a savanna may be mostly the Open (“prairie”) mixes, and a woodland may have open meadows and many areas (depending on the spacing of the trees) for the “Intermediate” mix. In fact it is in these areas that the bur and white oaks reproduce. 

ONE STEP MORE COMPLICATED


This graphic adds wetness to our decision-making. On the North Branch we deal with few areas of “dry” soils or even “dry-mesic” soils, so we’ll focus here on “mesic” and “wet-mesic” soils. 

(“Mesic is just fancy jargon for “average” moisture. That is, it’s half way between dry and wet.)

Thus the graphic suggests where to plant the six different seed mixes that we need here:

WMP: Wet-Mesic Prairie 
WMS: Wet-Mesic Savanna  
WMW: Wet-Mesic Woods  
and
MP: Mesic Prairie  
MS: Mesic Savanna
MW: Mesic Woods  

Note that the very open woodland here has as much "savanna" as woodland seed. 

How do we define the term “Savanna” for seed mix purposes? It’s an area that sometimes has full sun but is shady 40 to 60 percent of the time – whether because one or two big trees puts it in full shadow for part of the day, or because the overall tree canopy has enough holes in it that any given piece of ground gets sun for 40 to 60 percent of the day. 

The graphic may seem complicated, but on the ground you can work it out. In relation to trees, are you: a) far from, b) near, and c) under? Recognizing whether you’re in mesic, wet-mesic or wet soils is trickier. You can often tell from the existing vegetation. For example, white oaks suggest “mesic.” Swamp white oaks suggest “wet-mesic” or “wet”. But you can also often judge more simply (especially as you’ve become more familiar with your site) because on the day you’re seeding, the areas you know to be mesic may be light brown; the wet-mesic on that day are dark and damp, and the wet areas have standing water. 

Consider Existing Quality 

When broadcasting seed, consider competition from the species already growing there. It you have bare ground where brush was just cut, plant a simple basic mix. If an area is dense with tall goldenrod and briars, don’t invest too much rare seed there yet. 

On the other hand, the highest-quality seed (“Turf”) prairie mix should be broadcast into thin old-field turf (made up, for example, of bluegrass, daisy, carrot, and early or gray goldenrod). This approach has been proven effective by long experience on the North Branch.

If you’ve thinned trees in a pretty good quality woodland (with some understory plants like Penn sedge, pussytoes, elm-leaved goldenrod, bellwort, etc.), save your more conservative species for there. These might include shooting star, wide-leaved panic grass, and rue anemone. For more detail on “high quality” or “conservative” species see: 
https://woodsandprairie.blogspot.com/2018/07/a-myth-coming-true.html

What’s your experience?

Please keep careful records, and share what you learn.

If you’d like more detail on these questions


Acknowledgements

Thanks to Eileen Sutter for much improving this post for North Branch seminar use. 

Friday, October 12, 2018

Giving Rare Seeds a Good Start

More Than Perhaps You Wanted To Know
But Then, Perhaps Less Than You Need To Know
If You Want To Competently Restore An Ecosystem

(This is a draft – being edited – comments appreciated.)

Rarely Asked Questions 
(and Possible Answers, not pretending to be the last word – in this evolving discipline of the restoration of quality plant communities)

RAQ1: Why is it important to plant seeds in the right place? 

PA: Some people say we wrongly “play God” in deciding which seeds to plant where. And in theory, the most natural method would be to plant all species everywhere – and let God or nature decide which would prevail. But our most important seeds are rare – and harvesting rare genotypes from the wild, as we do, diminishes the place they’re taken from. Take too much too often – and we do damage. This is especially true of the seeds of now-rare, formerly dominant conservative species. 

So, we don’t want to waste them. Also, the seeds of wetland plants won’t propagate on dry ground, and although middle-moisture seeds might survive for a while in somewhat drier and somewhat wetter habitats, they’d be replaced by more fit species in time. The same could be said for species of sun or shade. Thus, if our goal is to conserve rare biodiversity, we can’t ethically waste.

Reassuring note: This account – drawn mostly from experience at Somme Prairie Grove – won’t concern itself with the complexities of less common soils like sand, clay-pans, etc. but will stick with prairies, savannas, and woodlands rising from the typical black soil of the tallgrass region. Also, this post is a “draft” prepared for a North Branch Restoration Project training exercise for stewards and Seeds Workday Leaders. We’ll learn enough through feedback to update these ideas after the exercise?

RAQ 2: Should we plant the same species in bare ground (where brush was cut) … compared to a grazed out old field that just needs more diversity?

PA: This is an important question, worth being aware of, but the answer is complicated. Many of the most important species won’t do well on bare ground, so we save them for “turf” mixes. But detail on this tangled question is relegated to Endnote 1.

RAQ 3: How do I recognize where I should stop broadcasting the prairie seed mix and start doling out savanna seeds?

PA: The first answer is that you’ll want to overlap those mixes a bit – as we’re just not that smart as to know for sure, and, indeed, the species mix naturally. 

The second answer is that it depends on how far apart and how big the trees are in your savanna. A rule of thumb: if full sun shines on a piece of ground for two thirds of the day or more, plant prairie seeds. But there’s much more on this, below. 

RAQ 4, and last: In restoring an oak woodland, should all the invading shade be removed before I plant my first seeds, or should the process be staged? 

PA: Our knowledge of how to restore biodiverse woodlands is even more primitive than with prairies and savannas. Some approaches lead to an understory of briars, poison ivy, and such rank vegetation that seems to head in the opposite direction from quality. With a lot of effort, it seems to work well to open the canopy enough for oak reproduction, plant diverse species for that level of sunlight, and let ecological processes take it from there. But other approaches may also show promise. (More on this in Endnote .) 


Some Visuals That Might Help

Many restoration principles can be expressed simply, but recognizing how to apply them on the ground in a specific place is the real challenge. Don’t expect to be perfect at it. In fact, just go ahead and assume that you won’t be right all the time and in every detail. But thinking about the principles ought to help. And field exercises help the most. The visuals below were designed to help prepare for field exercises. 

GRAPHIC SHOWING WRONG APPROACH

The graphic above seems to say: “Put the Prairie Mix in the prairie and the Savanna Mix in the savanna.” No, sorry, that’s not the way.  

Probably the seed mixes shouldn’t be called “Prairie,” “Savanna,” and “Woods.” 
Probably they should be called something like “Full Sun,” Part Sun,” and "Dappled Shade.” 
For more on this unfortunate terminology, see Endnote 3.

LESS WRONG, BUT STILL WEAK
This graphic gets us closer to reality. Most open savanna should be seeded with the “Prairie” mix. But immediately under and around and especially to the north of isolated large trees (considering how the sun’s rays slant at our latitude), plant the “Intermediate” mix. In the darkest parts of the savanna, blend in some “Woods” mix. 

There is no “maple forest mix” on this map, because the North Branch had little of the maple/basswood or maple/beech forest (and those fine natural communities are a good deal less threatened than oak communities, so there’s been less research as to restoration techniques or conservation goals or priorities). The restoration we’re considering in this exercise is for oak woodland and oak forest, which have much brighter understories than a maple forest. 

Notice, above, that the seed mixes to be planted in a savanna may be mostly the Open (“prairie”) mixes, and a woodland may have open meadows and many areas (depending on the spacing of the trees) for the “Intermediate” mix. In fact it is in these areas that the bur and white oaks reproduce. 

BEST GRAPHIC, FOR NOW

This final graphic is “as good as we’ll get” in this post – and perhaps a “good enough” approach for this simple site. It adds wetnessto shadein our decision-making. On the North Branch we deal with few areas of “dry” soils or even “dry-mesic” soils, so we’ll focus here on “mesic” and “wet-mesic” soils. 

(Note on the ugly word “mesic.” It’s just fancy jargon for “medium” moisture. That is, it’s half way between dry and wet. I apologize for it. But it’s so widely used in conservation, that we may be stuck with it. See Endnote 3, in the unlikely event that you want to think more about jargon considerations.)

Thus we’ll decide where to plant the six different seed mixes that we need here:

MP: Mesic Prairie  
MI: Mesic Intermediate
MW: Mesic Woods  
and
WMP: Wet-Mesic Prairie 
WMI: Wet-Mesic Intermediate  
WMW: Wet-Mesic Woods  

How do we define our shadiness term “Intermediate” here? It’s an area that sometimes has full sun but is shady 40 to 60 percent of the time – whether because one big tree puts it in full shadow for part of the day, or because the overall tree canopy has enough holes in it that any given piece of ground gets sun for 40 to 60 percent of the day. 

The graphic may seem complicated, but on the ground it’s not so bad. You’ll find it quickly becomes second nature to check where you are in relation to trees: a) far from, b) near, and c) under. Recognizing whether you’re in mesic or wet-mesic or wet soils is trickier. You can often tell from the existing vegetation. (See Endnote 4.) For example, white oaks indicate “mesic” and swamp white oaks indicate “wet-mesic” or “wet”. But you can also often tell (especially as you’ve become more familiar with your site) because on the day you’re seeding, the mesic areas will be light brown and the wet-mesic will be dark and damp. 

Also, a person who’s studying this insanely closely may notice that the “LESS WRONG” graphic treats some areas differently from the “BEST FOR NOW” graphic, as to whether an area deserves “Prairie,” “Intermediate,” or “Woods” seed.  

One Last Point 
(Oh! Please, no! Not more!)

Well, just a hint of one last consideration. When broadcasting seed, consider competition from the species already growing there – unless it’s bare ground where brush was just cut.  If an area is dense with tall goldenrod and briars, don’t invest too much rare seed there yet. 

The highest-quality seed mixes should be broadcast into thin old-field turf (made up, for example, of bluegrass, daisy, carrot, and early or gray goldenrod). This approach has been proven by long experience on the North Branch, Poplar Creek, Spring Creek, Flint Creek, and Orland preserves. More on this in Endnote 1. 

What’s your experience?

If you do this work, please keep careful records and share what you learn.

Endnotes
Endnote 1

Inter-seeding deserves more than an endnote, but this most-important and best way to plant diverse conservative seedat least deserves a quick summary here. 

For mesic prairie area, especially receptive is a diverse turf of “old field” species like Canada bluegrass, poverty oats, timothy, wild carrot, and ox-eye daisy. Even if you don’t know these species, you can probably recognize this kind of area as one where you can see through the plants down to soil all summer long. If the shade is too dark, prairie seedlings will die.  

In sandy soil at Nachusa, the stewards recommend planting all the species with the first seeding, and that seems to work there. At Fermilab, Dr. Betz recommended starting out with “first wave” species like big bluestem, Indian grass, and prairie dock – adding conservatives later. Most people today don’t recommend that approach.

At Somme we have mostly used two sets of mixes, one for bare ground where brush was recently cleared (although we often sow no seeds the first year to give us time to spray out invasive seedlings and re-sprouts). Sometimes in such situations we sow non-aggressive grasses that first year, to hold the soil and allow us still to spray broad-leaf herbicides). 

The second major mix is for higher-quality established turf. In an “old field” of daisies, bluegrass, poverty oats, and even smooth brome, we get good results from broadcasting the very “highest conservatives” including prairie clover, dropseed, Leiberg’s panic grass, shooting star, the phloxes, and everything good. Over the years, they out-complete and replace the weeds. (However, if the bluegrass or brome is so dense that it heavily shades the ground by summer, it is necessary to burn it for a year or a few before planting.)

In bare-ground woodlands, we hold back on such species as hepatica, betony, shooting star, and rue anemone until there’s a turf to hold them. We have less experience with woodlands.

In rank areas of tall goldenrod, sawtooth sunflower, Canada thistle, etc. we suspect there’s an appropriate mix to break promote diversity, but we’ve done little careful research on alternatives. In such areas, leadplant, dropseed, prairie dock, and Culver’s root (among many others) succeed well.  

Endnote 2

Fallen tree leaves act differently from the previous year’s old-field vegetation. We have found that few seedlings of most species can make it up through dense woodland leaf litter. So we try to plant such areas only after the leaves have been burned off. In some years, wind blows leaves into piles and leaves some areas bare, so we then seed those bare areas. 

Diverse woodland understories seem readily established in burned areas if sufficient seed can be broadcast. Mesic species that do especially well for us (and seem especially compatible with other conservatives) in the early years include elm-leaved goldenrod, golden Alexanders, nodding fescue, starry campion, and wide-leaved panic grass. Prime wet-mesic species include zigzag goldenrod, great blue lobelia, Virginia rye, and many sedges. Indeed, sedge species seem to foster diversity in woods from dry to wet. Since our seed teams can’t always identify all the sedges, we ask that they just gather what they find and label the bag with the habitat (wet prairie, dry open woods, etc.).  

Endnote 3

Conservation needs public support. Jargon alienates people. 

I tried to get the annoying word “mesic” out of this summary. Why not just speak English and say “medium”?! But in this case, that leads to the seed mix called “Medium Intermediate” – which is ridiculous. 

If anyone thinks it’s worth the challenge of trying to clarify terminology, I suggest possible alternate names:
For wetness: Wet, Wettish, Medium moist, Dryish, Dry.
For canopy cover: Full Sun, Half Sun, Dappled Shade, Deep Shade (or Full Shade).
Or perhaps: Full Sun, Part Sun, Light Shade, Full Shade.

(Note: Deep Shade or Full Shade would apply to maple forest. On the North Branch, we don’t have such a mix.)

It’s good for all stewards to know what “mesic” and “wet-mesic” means, so  you can read the technical literature. But we also need language to use with the general public and new volunteers.

Endnote 4

Since the quality species you’re seeding are likely not already present, you often you have to judge the wetness of an area by the weeds or invaders. 

Indicator plants for seeding mesic prairie:
Ox-eye daisy
Wild carrot
Canada bluegrass
Early goldenrod

Indicator plants for seeding wet-mesic prairie:
New England aster
Sneezeweed
Sawtooth sunflower (but don’t plant if it’s too dense)
Redtop

Indicator plants for seeding wet prairie:
Swamp milkweed
Sneezeweed
Blue vervain

In Intermediateareas, there’s rarely any vegetation beside brush. Check the Intermediate seed mix lists to find possible indicator species, if any are present. 

In woodlands, often the spring ephemeral species survive.
Indicator plants for seeding mesic woods:
Prairie trillium
Cut-leaved toothwort

Indicator plants for seeding wet-mesic woods:
Swamp buttercup
Fringed loosestrife
Mad-dog skullcap

Indicator plants for seeding wet woods:
Cardinal flower


Swamp buttercup

Wednesday, September 12, 2018

Forests Need Children


by Sol Hinami-Mayorga

The best adventures don’t happen in a pre-planned path. No self-respecting explorer of the past, present or future nor my 7 year-old daughter gets excited by looking at a mulched trail, graced by “stay on the path” and “don’t cut the flowers” signs. Adventure is fueled by hearing about other people's thrills, imagining them as your own and then advancing in a pathless direction. Imagination has always been fueled by the search of adventures.

For a city child, who might not have much access to the outdoors, adventures can happen in even the most dilapidated forests.

This dilapidated urban forest is raising its caretakers; they are people
who would not have had much exposure to nature otherwise. 
There is no coincidence that Theodore Roosevelt’s biggest source of pride was his preservation efforts. As a child he played outdoors. He loved nature and exploration so much that he and his cousins built the “Roosevelt Museum of Natural History” at home when they were 7 years old. Naturally, when he grew in age and power, he protected what had given him so much pleasure. He did it not just to preserve beauty; his goal was:

"to make the forest produce the largest amount of whatever crop or service will be most useful, and keep on producing it for generation after generation of men and trees." 

 I say – in an urban forest made accessible to children for playing, climbing, picking and digging a bit – that crop is called: people who love nature with all their senses. That crop is called healthy children whose minds and spirits thrive. Let’s call those spaces “play forests”.
Today's kids need wide-eyed memories of exhaustion, elation and fear,
mud under the nails and itchy scabs. 
Growing up in Mexico, my family would take my cousins, my siblings and me to a nearby beach, sit under a palapa and not look for us until sunset. We talked to fishermen, built dams, connected the ocean to an estuary, caught little stingrays. At night we played with fire and searched for turtles. We didn’t need to know the name or the reason the ocean glowed blue at night; it only mattered that it was beautiful, surreal and all around us. One afternoon I found a coconut that had sprouted and planted it. I did it on a whim, and up to this day, when I’m back at that beach, I look to my palm tree. She might not remember me, but I surely remember her. I was 7 years old then.

Now I live in Chicago and am raising my children in a beautiful, organized, and clean first world. But I can’t help notice that restrictions in natural spaces hamper the community’s ability to grow their next crop of lovers and protectors of nature. There’s an expectation that we should interact with nature only by walking around it or by restoring native plant species. Thus, a playable buckthorn mess turns into a crabby grandmother's living room, where the good tea set is never used, and the furniture is wrapped in plastic. Over-regulation of play in natural spaces takes away the adventure and risk by reducing the woods to a programmed activity with a clear start and a set end. Adults may not mind it because adult play may be mostly conversations rather than physical creation. Children do the opposite.

Today’s kids need autonomous and risky play in nature to grow up to be the best engineers, storytellers, policy makers, presidents, or whatever these bodies and minds will do in their futures. They need wide-eyed memories of exhaustion, elation and fear, mud under the nails and itchy scabs. They will remember cupfuls of flower-petal soup, cold toads stretching hind legs between the hands that hold them, and that half bunny in the woods that brought up so many questions. If they engage in climbing, building, finding and hiding miracles and treasures under logs – if they share the myths and the stains – then they will know with all their bodies what it means to love life outdoors, and they will imprint on their local surroundings.

When we truly enter a forest, the forest finds a way to get inside us too.
After all, this slow process is how nature has always raised its caretakers: By planting its spores in every person who plays in it. When we truly enter a forest, the forest finds a way to get inside us too.

We read about Norwegian children growing in their Forest Kindergartens or the Welsh children in their Adventure Playgrounds. But the movement to engage children and Nature is already happening in the U.S.

In the City of Chicago there is one wise Nature Center that hosts a play forest within a conservation forest. North Park Village Nature Center cares for a 58-acre forest. Twelve of those acres are still overrun with gnarly invasive buckthorn. But instead of cutting them down and planting something else, the directors of the Center encourage nature-loving kids to turn fallen tree limbs into huts, tree branches into swings, and flowers into potions. After 6 years, this successful program is yielding its first crops. “Walking Stick Woods” now boasts Chicago’s first year-round outdoor preschool, a surreal public art gallery, and a summer camp loved both by children and parents. One mother who visited often became the steward of the woods and another became a Master Naturalist. This forest's crop is the raising of its caretakers; they are all urban people who would not have had much exposure to nature otherwise. They come here because this whimsical forest welcomes them for who they are.

Of course, not all nature should be subject to the whims of kids. We need protected nature preserves too. But we need more forests, prairies and woodlands inside our children. We need something to preserve and someone to preserve it. Something to be loved and someone to love it. We need Nature and its wild children.

Sol Hinami-Mayorga lives in Chicago with her husband and two children. She is the founder and co-director of Fraternal Forest, a social enterprise devoted to helping nature educators and children meet in the woods. Photos show children in the Fraternal Forest Wilderness and Adventure School. See: http://www.fraternalforest.org

Thanks for proofing and edits by Eriko Kojima and Kathleen Garness. 

Tuesday, August 28, 2018

Are Woodland Sunflowers Thugs?

I still don’t know if the woodland sunflowers are a savior or a threat. I can loftily say “They’re clearly part of a long-term complex process.” But that doesn’t help with the life-or-death decisions we have to make as stewards. 

In restoring savannas and oak woodlands, our goal is recovery for the full diversity of nature. But what is that? Nobody knows, because wooded tallgrass ecosystems degrade rapidly in the absence of fire, and they degraded for more than a hundred years, prior to our recent adventures in biodiversity restoration (See Endnote 1). 

Thus, for savannas and woodlands, we’re starting at a low level of quality – and a low level of knowing what to aim for (which we wish we could base on healthy “reference ecosystems” – if they existed). 

Woodland sunflowers seem to be taking over large parts of our savanna and woodland restorations. Is this good for biodiversity conservation – or a threat?

At Somme, quality indicators have been rising for decades. Those graphs seemed to validate our strategies (see Endnote 2), but there were worrisome trends. In the oak woodlands, for fifteen years an increasing infestation by the “malignant” tall goldenrod (Solidago altissima) worried us. We hoped this thug would eventually be out-competed by conservatives. Indeed that seemed to be happening, and the weedy goldenrod is largely gone. But as diverse conservatives increased, so did woodland sunflower, which sometimes seemed even more thuggish. 

Other stewards have noticed the same. In Wisconsin, Tom Brock felt the need to control rampaging woodland sunflowers. His excellent website documenting savanna restoration lists woodland sunflower among “Native species that have been invasive”. He has experimented with herbiciding it. 

Will woodland sunflowers ultimately "play well with others" in restoration (as, for now, in the foreground, above)? Or will they blot out most other vegetation (as in the background, above, when we looked close)? 

In Vestal, we don’t herbicide, pull, or otherwise control woodland sunflowers. We nervously appreciate them for apparently controlling the tall goldenrod pest and a part of the natural ecosystem. But if, at this stage, they were to malignantly suppress most other vegetation – they’d wipe out decades of work, including the habitats for hundreds of rare animal species. 

Diverse conservatives, laboriously restored. Might woodland sunflower wipe them out? Apparently, no one knows.
Conservative woodland species in the photo above include robin plantain (white with yellow center, right), stargrass (six yellow petals, right), bastard toadflax (five pointy white petals, top), grove sandwort (five rounded white petals, center), shooting star (wide leaves and purplish stems, top left and right), cream vetchling (wide leaflets and tendrils, top half), blue-stemmed goldenrod (pale pointed leaves at top), and the commoner wild geranium (pretty pink petals). 

Even though warned in 2014 by Tom Brock, we’ve continued to mostly ignore the sunflowers. Before this year, I couldn’t even name them. Four similar species can be sorted out by experts, allegedly. But on multiple occasions we’ve asked experts, respected professional botanists. Their answers at first didn’t seem to agree with each other; then after a few more searching questions, we seemed to hear a lot of hedging of bets. 

We’ve tended to refer to the four species of “woodland sunflowers” collectively – without giving them species names. The four, as they appear in books, are: 

Helianthus decapetalus – pale sunflower or thin-leaved sunflower 
Helianthus divaricatus – rough sunflower or woodland sunflower
Helianthus hirsutus – oblong sunflower or hispid sunflower or stiff-haired sunflower
Helianthus strumosus – pale-leaved sunflower or woodland sunflower

Perhaps one of the reasons that the common names are inconsistent from source to source is that common-name-users give up on these four. Indeed, John and Jane Balaban, the botany-heroes who first mastered the sedges for the North Branch Restoration Project, threw in the towel on those four. As John recently wrote, “ I found great difficulty in keying them out … Things just didn't seem to add up.”   

Swink and Wilhelm quote the great Henry Alan Gleason who wrote: “H. strumosus apparently passes into H. decapetalus in one direction and H. hirsutus in the other.” Apparently, no clear line divides these “species”. So, do we care? 

Thomas Antonio and Susanne Masi wrestle briefly with this question in The Sunflower Family in the Upper Midwest. They point out that: 

“Members of this confusing group are found in similar habitats and frequently hybridize, making their identification even more difficult … Experienced botanists frequently have great difficulty with this group. Pale-leaved Sunflower is considered the most variable of the perennial Sunflowers, and hybridizes with a large number of species. It has even been termed a “wastebasket” species, because difficult Sunflower specimens are placed under this name when they fit no place else (Heiser et al. 1969).” 

Antonio and Masi also spice up the discussion with this tidbit:

Researchers have found that Helianthus decapetalus is the only Sunflower species in which two different chromosome numbers are present: 34 in general for those growing in the western parts of its range and 17 in the eastern part. An exception to this east-west distribution is found in the Appalachian region where both types of H. decapetalus have been identified (Rogers et al. 1982). Although these plants cannot interbreed, and should therefore be technically considered different species, they are visually or morphologically indistinguishable from one another in the wild (Heiser et al. 1969). For this reason, botanists continue to classify them as the same species. 

Oh God! Oh Darwin! Please help us! In practice, botanical keys define species. On hard-to-identify groups, experts may say: “It depends on your species concept” or “It depends on which key you use.” Every book seems to have a different key – even different editions of the same book: For example, the Helianthus key in Swink and Wilhelm (1979) was changed for Swink and Wilhelm (1994) and again for Wilhelm and Rericha (2017). They keep trying.

But do the differences among these species impact the ecosystem? Do the different "species" behave differently? What is the ecosystem role of the various woodland sunflowers? Motivated by their progressive take-over at Somme Prairie Grove, we realized that for biodiversity conservation, it’s a life-and-death matter whether one species is compatible with (or fosters) sustainable biodiversity in a given situation and the other species is a malignancy that wipes it out. 

As we plan, we check early records for clues. Surprisingly, H.S. Pepoon’s 1927 Flora of the Chicago Region doesn’t quite list woods as habitats for the “woodland sunflowers”:

Helianthus decapetalus – thickets throughout, common
Helianthus divaricatus – common in thickets and brushlands
Helianthus hirsutus – dry soil … rare
Helianthus strumosus – banks of streams and moist borders of swamps, common

These days, as Pepoon’s notes might suggest, after four decades of brush cutting and controlled burns, we see sunflower clumps most impressively on edges. Some clumps are six feet tall, have abundant wide leaves, and little else growing underneath. Others are three feet tall, less dense, often with fewer or narrower leaves, and more diversity in between and under them. Are these different species, or the same species behaving differently? 
Each sunflower clump starts with a single seed, and then spreads densely,
especially if the adjacent vegetation is of low quality. 

Last year, botanist Will Overbeck suggested a way out of our frustrating species confusion. We had been taking distinctively different plants and trying to key them down, to see which was which. These sunflower plants start with one seed – but then spread mostly by runners. Clumps ten or twenty feet across are often “all the same plant.” The whole clump started from the same seed. Since these species are internally variable, one six-foot tall clump with purple stems and large leaves may be the same species as a nearby clump three-feet tall with green stems and small leaves – just as two people may be different heights and different complexions. 

So, especially if a large proportion of plants are hybrid mongrels, Will suggested we first figure out which clear species were present and then recognize the rest as blends of those. Okay, Will, we decided to buckle down and do that, as best we could. 

We found it helped for us first to put the woodland sunflowers into two groups based on their leaf stems. In two species – strumosus and decapetalus, the leaves gradually get narrower as they approach the stem (technically, a “decurrent” leaf). 
 
To distinguish among the three species above, we first check out the bases of the leaves. The four leaves on the left narrow gradually, just above the stem. The two on the right have "flat bottoms" – without that narrowing. 

Once we’ve determined whether a clump has a blunt leaf base, then we step back and look at a few more characteristics to assess whether that plant is a clear species, or a messy hybrid. 

In the case or our decurrent friends, it’s fairly simple:

The leaves of Helianthus strumosus are more than three times as long as wide. 
If the plant is pure strumosus, it will also have a smooth lower stem and short green bracts beneath the flower.

The leaves of Helianthus decapetalus typically have longer stems, are wider, and often have bigger teeth.
If the plant is pure decapetalus, it will also have long, unruly, narrow-pointed bracts underneath the flower. 

We had a harder time telling the difference between hirsutus and divericatus. In the end, we had to admit that we could find no pure divaricatus at Somme. Perhaps we have some of it in the hybrids, or perhaps we have just the other three species. 

The main clue to hirsutus is its coarse hairs on the lower stems (in contrast to the two species above, which have smooth lower stems). 


Helianthus hirsutus has roughness and coarse hairs everywhere.
Photo by Jan Thomas Johansson.


When you're checking out the leaves, hirsutus has the blunt (non-decurrent) base.
The two main veins meet the midrib less than 1 mm from the stem.
(Compare with the two decurrent species, above, where those veins end farther up the leaf).
So that's the cast of characters. Now, we can start to answer our nervous earlier questions. Our first Somme Prairie Grove species list did not include any woodland sunflowers. But they were (and are) common in dense patches adjacent to the preserve along Dundee Road, in the occasionally mowed strip just outside the buckthorn death zone. We didn’t plant it. Our strategy in prairie, savanna, and woodland had been to hold back on the most aggressive species until later in the process. Woodland sunflower does not turn up in our initial (1985) Vestal Grove transect sample. It appears in the second Vestal Grove sample (1987) and has been increasing since then. 

Overwhelmingly the most common form in the shady Vestal Grove is that “wastebasket species” – strumosus – with perhaps a little decapetalus (or decapetalistic hybrids) here and there. Very gradually, with us little noticing, like the proverbial frog in the heating kettle, it took over. Now we woke frogs recognize great masses of woodland sunflower, fairly dense in perhaps half of Vestal Grove. This year, when we started looking harder outside the grove, hirsutus and hybrids seemed more common, out in that brighter light. 

We're currently analyzing a 32-year vegetation dataset for the Grove and will soon have a better sense of whether this species is eliminating others - or perhaps contributing to a more stable and conservative diversity.

Outside the Grove, it's scarier. Often there is little or nothing under the hirsutus and strumosus-hirsutus hybrids. We have little data on that. It's time to study.

We found little pure decapetalus, which fit with Wilhelm and Rericha’s characterization of this species as “uncommon” (while they rate hirsutus and strumosus as “frequent” and “common”).

But we expanded our searches across the street, and there we unexpectedly found decapetalus to be the species springing up most frequently, as part of the recent rapid recovery of Somme Woods East.  

That long-suffering, buckthorn-choked original woodland (in contrast, Vestal Grove and Somme Woods West seem originally to have been savanna rather than woodland) retained some of its spring flora, but little else, we had thought. The recovering summer and fall flora has mostly sprouted from the seed we diligently hunted, gathered, and broadcast. But this year our survey found full-grown (apparently young) little clumps of woodland sunflower, mostly scattered, tens or hundreds of yards apart. These “clumps” were typically just a few stems, unlike the hundreds per clump in and around Vestal Grove. We had not seeded these new clumps. Where did they come from? “Seed bank” seems unlikely for sunflower-type seeds. Might they be the remains of huge old clumps where the roots have survived on the basis of what little light they could gather, with gradually diminishing strength, until we came along? Are they precious summer flora remnants?

Will it help us avoid the dreary tall-goldenrod-stage of early restoration? Or is it a threat that we should control before it builds up too much steam? Is decapetalus more or less thuggish than strumosus or hirsutus? What kind of monitoring should we do, to understand it better? At other sites, woodland sunflower may or may not be a concern (see Endnote 3). 

Gerould Wilhelm has written about the "floristic symphony" of fall color – of asters, goldenrods, and with the woodland sunflowers playing first violin. We’re learning much and will write more on these possibly-dangerous beauties soon. 

Endnotes

Endnote 1
White and bur oak woodlands and savannas developed their biodiversity over the ages with regular burns. Their biota benefits from – and requires it. After the takeover by the Euro-Americans, lightning- and Native American-set fires were suppressed by these farmers, who depended little on the animals and plants of nature. 

Some of the first tallgrass woodlands to resume prescribed burns were at Somme and the Morton Arboretum. Many aspects of these two sites have been studied intensively, although you might doubt it, given that we only now recognized what was happening with woodland sunflower. 

Tallgrass or black-soil savannas are somewhat similar to black oak savannas, which developed on sand deposits. Being less fertile, these areas degraded less rapidly. Also, sand areas – being less valuable “wastelands” – in some cases were regularly burned by kids, hunters, or others, without much repression effort by authorities. So we have some ecologically high-quality ones, for example in scattered areas of Calumet, Illinois Beach, and Pembroke Township. 

Endnote 2
Our basic strategy has been to plant as diverse as possible richness of seeds, especially those of conservative species. The plant community can be expected to go through many evolutions on the way to high-quality sustainability. But if a large component of the species can be restored early on, then they will be able to move and adapt to new niches as they develop. 

Endnote 3
Comments from other sites.

On Aug. 11, John Balaban wrote about his experience at Harms Woods in Glenview, IL:

I found great difficulty in keying them out using Swink & Wilhelm. Things just didn't seem to add up. I recollect that I often ended up at Hel hireven for plants that looked different. I haven't tried keying them in the new flora, but I had it in my mind to give it a try this year. I can't remember any places in Harms where the sunflowers seem aggressive, but I haven't had that question on my mind as I walk around. I will try to look for it next time I'm out. Harms is still full of Solidago altissima (tall goldenrod), so maybe we aren't at the sunflower invasion stage yet.

On August 12, John wrote:

I had a short walk at Harms with Jonathan today. We looked for Helianthus and found a few but not many and did not seem to be aggressive.

On August 12, steward Larry Hodak checked out Linne Woods (in Morton Grove, IL). He wrote: 

This is a relatively high quality woods, and there are three distinct patches of sunflowers. I don't feel they're marching to take over as I don't think they've expanded much over the years, but there is definitely less diversity in at least one of the clones. The best I can key the species out is H. strumosus.  There is also a patch along the railroad that I think is H. divaricatus (not 100% sure on either). I tried both keys but appressed hairs on the internodes stymied me).”

Tom Brock wrote me after seeing woodland sunflower photos in this blog in 2015. He was trying to be helpful, as I still had not focused on this species. He restores savanna at Pleasant Valley Conservancy in Black Earth, Wisconsin.

Cutting did not work for us. If anything, we got better growth. Also, hand pulling was unsuccessful, because it was impossible to get all the underground material.

I spent some time trying to figure out how “our” Helianthus grows. The rhizomes are fairly short. Once a new shoot is formed, the parent rhizome dies, but the new shoot sends out more than one new rhizome. Because of the short rhizomes, the stem density of the patch is very high. There must be almost no light reaching the soil.

Curtis and Cottam did a study in the 1940s or 50s on a perennial sunflower. They had evidence of allelopathy and also autotoxicity. Thus, the center of a clone often dies but the periphery continues to spread. We have confirmed this with marked clones.

Our best herbicide control has been with use of 20% Garlon 4 in bark oil. A single “spritz” at the center of the shoot is enough to kill that stem. (See the attached photo. The red dye shows where the plant was sprayed.) I was successful in eradicating small clones (6-12 ft diameter) using this procedure. Had to return several times after the initial treatment to treat the late-growing stems. Must continue to return the following years to get the few new stems that keep on coming up. 

This procedure is much too time-consuming for larger clones, so we just treat several rows on the circumference to keep the clone from spreading. (Even that is time-consuming.)

In 2009 we did a survey at Pleasant Valley Conservancy in August, during the flowering stage. We found about 75 clones, some small, others quite large. Most of the large clones were confined to mostly open savannas in areas with sandy soil. Unfortunately, since then many of the smaller clones have coalesced into quite large ones.

For more on Tom’s battle with the sunflowers, see http://pvcblog.blogspot.com/2014/06/woodland-sunflower-still-out-of-control.html
http://pvcblog.blogspot.com/2009/08/woodland-sunflower-invasive-native.html 


Acknowledgements

Thanks to Kathy Garness and Eriko Kojima for proofing, as always.