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Wednesday, June 14, 2017

The Science and Secrets of Un-named Pond

The pond actually has a name. But this post reveals too much to use it.
There are so many human feet in the Chicago metro area that excessive publicity and visitation risk death by trampling.
If you visit the Somme preserves, please stay on the trails during the growing season.

Somme has ten substantial ephemeral ponds and many more "pools" that hold water briefly. If you're an avid botanist and feel the need to explore them, a less damaging time might be in fall when they're dry (so your feet won't churn up the soil) - and the vegetation is largely dormant. If you're a bison, you can walk in them at any time, but that's another story.

At Un-named Pond there are scores of species of plants that are at least locally rare. We planted most of them, adding complexity that is discussed below.

Un-named Pond has populations of five endangered plant species. One of them is the spectacular American slough grass - or, even more impressively, Beckmannia syzigachne.

Beckmannia syzigachne pops up in Un-named Pond some years by the hundreds - and some years not at all.
Today I found it in 5 areas, for a total of 11 plants. 
We don't know if the population of this annual grass is original, introduced, "restored," or a combination. The first time I was ever in this pond, by chance, was with biologists from the Illinois Natural Areas Inventory in the 1970s. They were looking for Beckmannia, which had been reported for this pond by botanist Marion Cole. None of the INAI botanists had ever seen the plant and had only a vague idea of what it looked like. They didn't find it.

Years later we studied Beckmannia in books and looked for it carefully. We didn't find it then either. But we did find it at another North Branch site - Sauganash Prairie Grove. Acting on the coaching of our mentors, we moved some of the seed from Sauganash to Un-named Pond. We saw no results for years.

Then, one year, we found one plant. It didn't seem to set seed. We seemed to find the same one increasingly big plant for the next three years. Wondering if its genes needed some more diverse alleles, we scattered some Sauganash seeds nearby. The following year, that one big plant was joined by a few little scrawny new ones, where's we'd scattered the seed. The plants seemed to set good seed that year. Then no plants the following year. But over time they started appearing most years, not in the same place, but widely scattered around the pond - in the temporary associations as described below. In 1998, most of them were eaten as the seed was maturing, apparently by deer. Next year interns caged some, and lots of seed matured. The Chicago Botanic Garden Plants of Concern program counted 550 plants in 2008. (The Sauganash population was destroyed during the 1990s, as part of the conservation hiatus called "The Moratorium" - so the Somme population may be all that's left on the North Branch.)

When we started caring for Un-named Pond, it was mostly an expanding stand of dense cat-tails (both "common" and "narrow leaved") with little growing underneath. Bits of richer vegetation survived here and there, so we started swiping cat-tails with herbicide to protect the biodiversity they seemed to be displacing.
Where only cat-tails - and then bare soil - once stood, the pond now is now diverse and complex.
Following our usual practice, we tried to gather and broadcast all species of seed that likely would have lived historically in that bare soil that briefly replaced the cat-tails.

All seed was gathered from spontaneously populations within 15 miles for prairie and 25 miles for woodland/savanna. Since part of this pond is shaded by oaks and part is completely open, we broadcast seed for woods, savanna, and prairie - in mixes called "pond," "sedge meadow," "wet," and "wet-mesic." That's a lot of mixes.

Our experience has been that many species are slow to establish - even though in the long run they may end up thriving. For many years the threatened species Veronica scutellata was a dominant species in one nearby pond - but absent here. In recent years, this plant, marsh speedwell, has been absent from that other pond, but doing very well here in Un-named. These wetland associations are rapidly changing from year to year - as the vegetation recovers from post-cat-tail bare muck.

Many plants, like this rare speedwell, seem to move from place to place -
including moves of substantial distances to place we'd never have thought to sow them.
Ecosytems have their ways. 
Another puzzler is a sedge (see photo below) that botanists also seem to have a hard time with. One famous botanist told us it was Carex laeviconica. We thought we showed the same plants to another, who suggested Carex atherodes. A third botanist felt confident it was Carex vesicaria. In this case, he forwarded a specimen to a national authority far away, who went back and forth and, at last report, was still undecided. Do we have them all - and different ones fruit in different years, depending on conditions?

Whatever its legitimate name, the species shown below is an abundant plant some years in a pond somewhat similar to Un-named - and about 300 yards away. In 2012, we'd killed large areas of cat-tail, so - in addition to our other mixes - we gathered a shopping bag full of vesicaria or whatever it is (which happened to have an especially good year in that other pond) and broadcast it widely in Un-named Pond.

A bagful of rare seed. Sown in 2012. How many plants would result?
For two subsequent summers, we saw no vesicaria in Un-named Pond. Then in 2015 we saw one plant. In 2016 it was bigger; 2017 bigger still; but there's still only one.

One big plant of vesicaria (front left) stands annually alone, for now. 

It makes a crop of fat seeds every year. Will the population explode some year when conditions are right?
This is a continuing story - for so many species.
Many ecologists find that research suggests that natural communities are typically diverse. Many of us used to think that an "un-diverse" solid cat-tail marsh was "nature." Now most ecologists believe that such a marsh is a suffering, degraded system.

But how much diversity can a marsh recover from solid cat-tails or some other degraded monoculture? Our stewardship of Un-named Pond is one experiment that may help answer that question. We have offered this pond seed of well over one hundred species (if you count the various sunny-to-shady and wet-mesic-to-deep-water species).
Here - where cat-tail was recently herbicided - Carex crus-corvi competes with Iris, Sium, Alisma, and others.
In some places where seed was not broadcast, Iris is now nearly a monoculture.
We were "less aggressive" or "neglectful" earlier in our stewardship of this pond. At first we controlled the cat-tails and assumed that nature and the seed bank would restore diversity. That didn't happen. Large areas became solid Iris virginica.

Big expanding stands of solid iris or any other "monoculture" or "few culture" probably means
that biodiversity conservation is not succeeding as well as it might. 
Bluejoint grass (Calamagrostis canadensis) is another species that sometimes forms monotypic stands.
At Un-named Pond, some of these "death of diversity" zones seem to expand, slowly, but inexorably. 
I have not heard concerns from resource managers or stewards about iris or bluejoint grass, but I've seen areas where they seem to exclude most other plants. Perhaps such dominances in large, complex, rich communities may represent merely internal-successional phases. Or perhaps areas of monoculture are a natural feature. We worry especially about this kind of thing in the experimental and needing-intensive-care current state of Un-named Pond.

But we aren't doing anything about Iris or Calamagrostis - aside from continuing to find and broadcast diverse seed. (Do you have recommendations?) This year, for the first time, we find blooming bur-reed (Sparganium); it's from seed we brought (or ducks may have brought?) from another nearby pond.

In early years, the prairie white-fringed orchid (Platanthera leucophaea) grew in small numbers in one wet-mesic degraded remnant adjacent to the pond. But over decades of burning and restoration by broadcasting seed of missing conservative species, scores of them began to bloom each year in wetter, former-cat-tail areas. We recorded associated species and found a great many possible lists of associates, as the vegetation structure evolved. In 2016, an impressive 168 of these orchids were found in and around the pond.

At one point super-dense saw-tooth sunflower (Helianthus grosseserratus) wiped out the main patch of orchids (though some moved into the former cat-tails). We surgically scythed the sunflower for a couple of years, and the sunflower gave way to a more diverse community. Orchids never returned, but the endangered eared gerardia (Tomanthera auriculata) has been in that area ever since.

For many years, the slough grass (Beckmannia), an annual, appeared mostly in bare-ish edges where cat-tails had been controlled. Just last year they began appearing in deep-water areas, also where cat-tails had been controlled - but which were now dense with sedges and other deep marsh plants. Are they more sustainable associates for the Beckmannia? Or will it continue to move from place to place? Or will this population snuff out? We await the next acts.

We agonized a bit about buttonbush (Cephalanthus).  An argument could be made that it's natural here. But it may be more typical of woodland ponds - rather than savanna ponds. It could take up quite a bit of space - space that might be needed by many of the other rare species. Natural fires would historically have decided where and how prevalent it would be. But fires of that intensity are not possible here. So we now have to decide, one way or the other. We could decide to let just a few stay, but then one year we could be overwhelmed by thousands of seedlings.

We wondered what to do about buttonbush. We decided to pull it out.
This one got pulled right after posing for this photo.
It's probably here only because it's in the North Branch Restoration Project "Pond Mix." 

Though this post is mostly about plants, we also try also to think about and plan for animals. Un-named Pond is home to blue-spotted salamanders, dragonflies, tiny clams, and so much more. Today I scared up woodcocks three times - in one case a hen with three barely fledged chicks. Recently it's been very hot and dry. Ephemeral ponds now may be life-savers to young woodcocks.

Some of the pond's rare orchids and gerardias (neither in bloom yet, and invisible to most people) are as vulnerable to trampling. I've seen massive trampling here - apparently by people who "loved" the place or at least found it very interesting. We need more and bigger areas like this, so we could relax about our feet and feel more like bison.  

We stewards don't go to Un-named Pond ourselves this time of year, unless we have some management or monitoring that requires us to do so. If you'd like to help, you'd be very welcome. If you have research needs, please contact us.

And if the increasing richness of this pond (and the rest of the Sommes) makes you happy, then you're kindred spirits. In any case, it's a pleasure to be in touch, through this blog. Feel free to leave a comment.

Note:
A more "general public" post on Un-named Pond - that partly overlaps with this one - was also published today at: http://vestalgrove.blogspot.com/2017/06/the-drama-of-un-named-pond.html

7 comments:

  1. The monoculture issue is one typical of restoration. I collected a few seed heads of Carex buxbaumii from a nearby railroad track years ago and grew them into plugs. I planted these plugs in a wet area in my back yard. The Carex buxbaumii in my yard are nothing like the plants I've seen in natural areas. The plants in my yard are so dense and vigorous that they excludes almost all other species.

    The best solution I know is to transplant a plant from a nearby natural area with all the natural herbivores and parasites so the natural relationships are at least partially restored. This is what will allow diversity to begin to develop.

    Of course if your goal is to produce seed for restoration, like I am doing with the Carex buxbaumii, then you do not want to do the above because it will greatly reduce the amount of seed that is produced.

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  2. Enjoyed reading about this. The message here seems to be that restoration is possible, but takes advanced planning to have a viable seed source in preparation for herbiciding the cattails. You didn't mention the timing. When would you recommend doing the treatment and how long would you wait until you broadcast seed? Also, are there any new unnamed ponds in the works? Finally, what are your thoughts about managing these wet slough areas with prescribed burns? Been tried?

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    1. When we start removing invasives in some kind of habitat, we often wait a year or two to learn what comes from the seed bank. But, especially in most upland prairie and woodland habitats, it's very little. In this case, after a few years, we seeded each section as cat-tails were controlled in the autumn or early winter after the control.

      In cases where the cat-tail have left a deep layer of slowly rotting cat-tail, any seed bank may be lost, way underneath. It seems to me like a good idea to test removing the cat-tail rot down to the original wetland soil level. But this is not something I have tried.

      Yes, certainly, we burn these areas in the rare seasons when they're dry enough.

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  3. Thanks Stephen for another good post. It is great to read about other practitioner experiences. Typically, in wetland settings, we have our hands full just to control reed canary grass, purple loosestrife and exotic cattails. Having a lot of bluejoint grass and blue flag iris is usually considered a good thing. However, there have been cases where I use marsh betony to break up rhizomatous sedge dominance (could work for bluejoint grass too) and rope dodder to weaken sunflower dominance. Sensitive fern is another species that can suppress dominant sedges.

    David

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    1. Thanks, David Cordray. In "Un-named Pond" too we've had a long battle with reed canary, purple loosestrife, giant reed, and saw-tooth sunflower. I too have had positive experiences with dodder and betony promoting diversity. Do you find that broadcasting fern spores is effective? Or do you plant plugs? Keep letting us know more detail of your successes!

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    2. Stephen, To date, I have not found any ferns that have come from broadcasting spores. Maybe more time? However, planting plugs works well. Dodder and betony come in well from seed. While I typically use marsh betony for wet areas, I am amazed how wet an area wood betony will grow in. Wood betony is such a cool plant. I am working on a blog post about wood betony for the near future. Thanks again for your blog. David

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  4. What is your recommendation for controlling cattails in sensitive natural areas?

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