Went to the swamp; found myself

Last week, I described what I found out on the land during my tour of Iowa’s 99 counties. That entry, and this whole blog, is about wetlands. But with your indulgence, I’d like to engage in a bit of self-reflection. I’ve learned about more than just wetlands, as it turns out. While slogging about these past three years, I’ve come to understand three truths: the value of being myself, of being in community, and of being connected to place.

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Student artwork, inspired by a lesson on “modular growth” of cattails

To be myself

We scientists (at least, those of my generation) were trained to conduct science in a dispassionate, disciplined way. Our goal is to ask questions and seek answers mechanically, avoiding bias as much as possible. Even the dry, stilted writing we employ when describing our work (“data were collected…” “…these results may reasonably be interpreted to suggest…”) encourage us to pretend to be science-robots.

Although this approach has noble intentions, it is still flawed in two important ways. First, it suggests we might somehow avoid bias (we can’t), thus avoiding the difficult and messy work of actually confronting our bias. Second, it places an artificial barrier between scientists and others (young would-be scientists, or the general public). Why are we are then surprised that science is seen as elitist and out-of-touch?

This 99wetlands project was an acknowledgment that today, society needs scientists to remember to be human beings, and to make a personal connection with non-scientists. We need to share our passion as well as our knowledge, and to engage in important conversations. Time spent driving to the slough or writing a blog entry was also time spent asking what’s really important to me, and why, and how to convey that to my readers. I hope I’ve done that in this blog.

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Tour of Bee Branch project, Dubuque

Living in community

I don’t own a wetland. Every site I profiled belongs to a private landowner, or is public land. It was important that this 99wetlands story include stories about the people who own, love, work in, and enjoy wetlands. I was delighted that in sharing their ecosystems, they shared their stories: what makes this place special, what should my readers know about it, how do you care for this place, what are we learning through this work? Getting to know the wetland meant telling the stories of my fellow wetlanders, and I loved it!

Including my students in my forays was both natural and a delight. These young people bring such energy and enthusiasm. Their questions and observations make me think about my work in new ways. Teaching brings great meaning to my life, and introducing young people to the beauty and the business of the ecosystem is truly a privilege.

And where would a writer be without a reader?? Almost 10,000 viewers from 60 different countries…that’s worth my effort! The blog format encourages readers to post comments and questions, and that’s the best part. I enjoy hearing additional points of view, examples from others’ experience, and the occasional gentle correction when I make a mistake. Much like my media interviews, I hear a comment from time-to-time out in The Real World, about how someone learned something new, or that I shared something that brought a little joy to their day. It means so much to me.

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Landowners invest much thought into wetland construction and management

Connected to a place

I’ve lived in Iowa for over 20 years now; Iowa feels like home. What better way to get the “sense of place” every environmental scientist needs, than to explore? So now, I have a better sense of Iowa geography—river to river, woods to prairies, farms and cities. I know more Iowa history, even pre-history of ancient peoples. I’ve met a few more Iowans—from ranchers to scientists to photographers. My wanderings and adventures make me love the place even more!

This quest was part of the inspiration for a class I’ll be teaching in a few weeks called, “Iowa: A Sense Of Place.” It’s one of those first-year college seminars where we introduce students to the academic life, to many ways of learning and knowing. You better believe I plan to have a good time with the class! Like this blog, I want to tell lots of different kinds of stories. Like this blog, I want it to be interactive. Like this blog, I hope it is life-changing.

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This rustic sign ifts right in, don’t be ofFENded

Some Final Thoughts…

I finish the 99 wetlands in a tumultuous time, indeed. As I write this, our country grapples with racial injustice in a most public way, perhaps more directly than at any time since the 1960s. It suffers from an economic depression not seen since the 1930s. We’re living through the worst pandemic in a century.

I haven’t exactly enjoyed these past six months, to be honest.

One of the things that has proven a comfort at this time, is the joy I feel when I’m in nature. I encourage you, if you can, to go find a pretty spot and just be still. You can find all sorts of studies about the mental-health benefits of spending time alone, contemplating the natural world. You can experience the aesthetic of nature-inspired art. You can reflect on the spiritual writings of ancient mystics and prophets who communed with Nature. Or…you can just go, and have that time away from the stifling oppression of the stresses and demands of everyday life.

Maybe you’ll choose to go to a wetland in Iowa. Maybe you’ll see me there.

I plan to keep exploring the wetlands, but informally and intermittently. I’ll still blog from time-to-time. Maybe I’ll make some videos. I’m told I should write a book, and maybe I will. I’ll keep you updated on whatever crazy shenanigans come next.

Until then…thanks again, and stay squishy!

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End of the Trail…at least, the 99 quest is completed…I hope the fun continues!!

What The Wetlands Say

DSC_0062I’ve now traveled throughout all of Iowa, meeting amazing people and seeing remarkable wetland ecosystems. Across 124 blog posts, I’ve tried to share my excitement with readers about the sights, sounds…and yes, smells…I’ve experienced.

“But Paul,” you say. “Just what is The Big Picture of Iowa’s wetlands…?”

Well, certainly no one can deny that Iowa has more diversity than is immediately obvious. Despite the loss of more than 90% of the State’s wetlands, I still found natural fens, potholes, sloughs, bottomland forests, brushy swamps, wet meadows, and marshes. I observed resident and migratory amphibians, reptiles, birds, mammals and insects. Gorgeous wildflowers, intricate mollusk shells, gnarled driftwood, and the water itself, all have unique beauty.

DSC_0382My interest in history appears in stories about Native American burial mounds, traditional uses of plants, a profile of “Ding” Darling and the modern American wetland conservation movement, “ghost towns” and changing land use, and Superfund and other serious contamination…and how we’ve addressed our legacy. The story I didn’t tell, and the sites I couldn’t show, were the countless missing wetlands. The landscape still has scars and remnants of drained or filled wetlands, often quite obvious in Spring when fields are still wet, or at high flow events in streams and rivers which attempt to reclaim old oxbows or floodplains where the water naturally moved from time to time.

Sometimes a blog entry was less about the site itself, and more about what we do at wetlands—the business of wetland science and management. It’s fascinating to “read” signs of hydrology (water movement or characteristics) when a site is in fact very dry. Identifying plants and animals is a useful tool, and Iowa has knowledgeable and generous naturalists—mostly unpaid, yet quite expert—who help each other to learn the species and about their biology. We all use maps, aerial photographs (including fancy Infrared or decades-old historic shots), soil samples and marker horizons (glitter, anyone??), chemical analyses, and a well-developed series of procedures to accurately identify, delineate and classify wetlands.

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Redheads are handsome, yes…? 😉

I haven’t talked much about how to care for our wetlands, and I’d love to do more with that in the future. Science and my personal observations all confirm that wetlands are never isolated, but are connected to other elements of the landscape. Healthy ecosystems are dynamic and adaptive, always-changing. Although we attempt to isolate or standardize the condition of a wetland, that’s always a bad idea, even if well-intentioned.

This blog is proof that, deep down, I’m a teacher…and in particular a teacher who loves to share stories. Most of my favorite memories are of wetland visits spent with my students. We get wet and muddy. We try to observe the organisms close-up (but hopefully, gently and respectfully). We learn about the conditions of water and air and soil that together, over time and through the work of life itself, make these unique and beautiful places.

bottle_itFor some additional reflection on this quest, I encourage you to listen to an interview I gave with the news director at our local radio stations, KNIA-KRLS. You’ll find answers to questions like why wetlands are important, which of the 99 was my favorite site, recurring themes through the project, and what this all means for my other professional activity.

What was your favorite memory? What would you still like to learn?DSC_0264

Wetland lessons and beauty

DSC_0533Hello again, fellow enthusiasts! Sorry to keep you waiting (my last blog entry was in January…and today is the start of July!!) but all is well, and I intend to finish this journey through Iowa’s 99 counties very soon. Today we visit the Calkins Nature Area in Hardin County. [Actually, these photos are from my visit to the site almost a year ago: August 2019.]

DSC_0527The County Conservation Board has a well-designed nature center just outside the town of Iowa Falls, complete with informative displays and helpful staff. Regular readers of this blog know my fondness for public outreach and education. I especially enjoy effective interpretation, in other words telling a story—putting the observations you make at the site today, in a context of the geology and history of that place.

Outside is a delightful butterfly experience, then the trailhead. As expected, we’re heading downhill to where the water will sit.

Sitting near the river, in a wooded bottomland setting, is a wetland pond with a control structure to impound the water. Really, the walk to the wetland, and the trail leading further along the stream, is just as lovely as the wetland itself. Flowers near water’s edge and along the path, dragonflies swooping around me, and sections of till and rolling hillside made it a scenic walk.

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Lately, I’ve had reason to think more about how to tell the story of the wetlands of Iowa…actually, how to tell the story of Iowa! More about those musings later. For now, I welcome you back to my trek, and ask you to join me as I visit a couple more counties in coming weeks, and then step back and ask what we’ve learned. Please join me, add your thoughts and questions, and stay well, friends.

Remembering and Anticipating

DSC_0001This blog project will cross the finish line soon: I have only a handful of Iowa’s 99 counties remaining to profile. I’ve been on a bit of hiatus lately, but my intention is to finish posting the remaining profiles in the next two months.

I’m in a contemplative mood! Actually, my visits to wetlands almost always both evoke memories, and invite speculation and planning for the future. Certainly my time at Beaver Valley Wetlands in Blackhawk County in August had me both looking back, and looking ahead.

It began as I walked along a backwater surrounded by trees. Perfect spot for Wood Duck (Aix sponsa) nesting, and sure enough I saw a female with her fledglings paddling through the duckweed. I watched her lead them away from me, and later circling alone, keeping herself between me and the young. Was she glaring at me with annoyance? You read her expression and decide for yourself. Anyway, a wildlife family is a hopeful sign for the future.

A short walk brought me to a well-constructed boardwalk/viewing platform. The air around it was busy with swallows diving, darting, and swooping about. Tough to photograph on the wing, but I did get a shot with a Barn (Hirundo rustica) and Tree (Tachycineta bicolor) swallow perched near each other. Nearby an Eastern Kingbird (Tyrannus tyrannus) surveyed the situation from a lofty perch, and Canada Geese (Branta canadensis) noisily landed on a section of large open water. I took the opportunity to birdwatch a while and eat lunch.swallows

DSC_0056I reflected on the legacy before me. My predecessors loved this place enough to preserve and manage it as a natural area; better still, to provide amenities like this sturdy platform and comfy bench. And I pondered the names of donors or their families and friends carved into this “Tom Carter Memorial Walkway.” I’m truly grateful for people who, like me, love wetlands and work to preserve these amazing places.

I wondered about the future. A few more wetland wanderings for me, some blogging, and…then what? Hopefully, continuing this conversation at the very least. Presenting my own research, or reports on what others are doing to/for our wetlands. Musing about how best to protect, enjoy, learn, and teach about these amazing ecosystems. Hearing your questions and thoughts, too. And, most of all, I wish for a future where we, together, protect these wonderful wetlands…DSC_0061

Noticing the little animals

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This frog has sprouted legs, but needs more time before maturing to adulthood

Most of these blog posts are about Big Things, taking a whole-ecosystem or landscape-level view of wetlands. No surprise, as my PhD work was a big project advised by a big thinker. But, I do enjoy a close look at the little things, and in particular if I have a dip net with me at a wetland, it’s fun to get up close and personal with the animal life. At Christy Pond in Carroll County, I did just that.

You’ll most likely find the animals near plants which provide cover (shade, hiding space). Big “emergent” plants like cattail and bulrushes grow up out of the water, but how about Common Bladderwort (Utricularia macrorhiza)? This species holds pretty yellow flowers up in the air, but is a tangle of stems in the water. Attached to those submersed stems are bag-like traps (bladders) which catch and digest animals. (Admittedly, they will catch only really tiny animals).

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Bladderwort plant with aerial stem bearing flower, and a tangle of bladder-laden aquatic stems

You’ll find plenty of “primitive” or “lower” animals in a wetland pond. Sneer at them if you wish, but their lineage goes waaaaayyy back, and they have been very successful at what they do, for a very long time. For example, few animal movements are as graceful as a leech swimming, it’s like a ribbon undulating in watery flight. Snails adhere (even upside-down) to slippery, slimy surfaces, using a mouth shaped like a paint scraper to graze on surface growths.

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Medicinal leech with a bunch of snail comrades

Amphibian larvae (tadpoles or polliwogs) come in many forms, some hopping about on land in one season; some frogs take years to develop in the pond, becoming in some cases almost as large as your fist!

I should probably have a whole blog just for aquatic insects—so diverse in form and lifestyle and rich in species. Let’s look at this water bug as just one representative. Now, I’ve heard people refer to just about anything as a “bug,” from butterflies to earthworms (seriously!). But technically, a “true bug” is a particular type of insect with sucking mouth parts. Either as a member of the Hemiptera (“half-wing”) or specifically grouped as Heteroptera (“different-wings”), they all wear the mark of their clan on their back: a big X where the wings cross (one folded over the other). The leading portion of the wing (forewing) has a heavy, protective texture (it even looks like a shield!), while the trailing portion (hindwing) is thin and flexible. To my eye, this animal looks like a little, streamlined dinosaur. Fierce and beautiful.

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Water bug, ventral (belly) surface…sorry, I didn’t get a photo of the X-back.

If you visit this park, bring a snack. The wetland is on the lower part of the property, but near the street is the old farmstead. It’s a nice shady spot to rest, and you can even explore an old farm outbuilding. All in all, I’d call this an excellent spot to experience rural Iowa and its wetland life. Enjoy!!

Input on WOTUS rule…?

DSC_0195Americans are encouraged to provide feedback and guidance on a proposed change in how the Nation defines, and therefore protects, our wetlands. The comment period ends on Tax Day (April 15). I hope you’ll have your say!

At issue is how to define “Waters of the United States” (WOTUS) which are the lakes, rivers, wetlands, and similar water bodies to be regulated by the Clean Water Act (CWA). President Trump ordered Federal agencies to look at the issue, and propose a new rule to define and regulate WOTUS. The proposed rule and related information, including how to comment on the proposed change, and the written public comments already received, may be found on-line at those links. Readers of this blog might very well wish to input on specifics of the proposal, or simply express support for a particular point of view regarding the issue. (All public input is solicited).

A consortium of nine different aquatic-related societies issued a statement in December about this proposed change. None other than Iowa State University Professor and past President of the Society of Wetland Scientists, Arnold van der Valk, is quoted in the statement:

“It will result in the loss of many of the nation’s wetlands. This decision is shortsighted and counterproductive. It will significantly reduce the multitude of ecosystem services that these wetlands currently provide us at no cost. As a result the taxpayers will have to pay to build elaborate and expensive infrastructure to replace these free ecosystem services, such as flood reduction
and cleaning up polluted water.”

…and he is 100% correct. This rule will result in the Nation losing many wetlands, and all the services they render.

I also recommend a New York Times article on the issue:

Regular readers of this blog have heard my thoughts on why wetlands should be protected, i.e. the various important work they do. New visitors (welcome!!) or those wishing a review might consider clicking on the “tags” in the sidebar for categories of “ecosystem services,” listed under Hydrology, Pollution, and so forth.

“But Paul,” you say. “How would a rewording of the definition of ‘Waters of the United States’ affect wetlands?” Because most of the wetlands in the USA will be protected (or not) through the Section 404 provision of the Clean Water Act. If wetlands are WOTUS, then the US Army Corps of Engineers must regulate their physical structure (“dredge and fill”) and the EPA must regulate their water quality. But if wetlands are not WOTUS, then…individual States may choose to protect them, or not.

DSC_0235Supposedly this new rule will “…increase predictability and consistency…” of wetlands regulations, and that certainly sounds appealing. But actually, since 1986 the Federal government has had a Rule about WOTUS that was, more or less, consistent and effective. In 1987, the Corps of Engineers published a Manual for determining what is/is not (i.e., delineating) a wetland based on that Rule. Although an Obama-era rule tweaked it slightly, the 1987 Manual, and the Rule it’s based on, has worked just fine. That’s over 30 years of practice—and this new Rule proposes to stick to it, with an important difference: adjacency.

The new Rule would require a wetland (as defined by the 1987 Manual) to be physically adjacent (“abut”), and connected to, a surface water body relating to other WOTUS (“jurisdictional waters”). In other words, a wetland must have a surface flow (in or out) connecting to a stream, river, lake, or other waterway already considered a WOTUS. That surface water flow or connection must exist in a “typical year,” not just a year with high water (i.e., flooding conditions).

I admire the honesty of frank statements in the Federal Register regarding what this rule is designed to do: eliminate protection for all wetlands not linked by a surface water flow to other WOTUS. Here are specific quotations:

(the proposed rule) would exclude isolated wetlands with only physically remote hydrologic connections to jurisdictional waters. Under the proposed definition, ecological connections alone would not provide a basis for including physically isolated wetlands within the phrase “The Waters of the United States.”

(the proposed definition) of “adjacent wetlands” and the categorical treatment of jurisdiction over wetlands adjacent to tributaries as proposed in informed by, though not dictated by, science.

Wetlands separated from other “waters of the United States” by upland or by dikes, barriers, or similar structures would not be adjacent and would not be jurisdictional wetlands under the proposed rule…

That last one is interesting. Several statements in the proposed Rule seem to suggest that even a wetland physically adjacent to a stream or lake will not be regulated, as long as you put up a barrier (like an earthen dam or berm) between the wetland and the adjacent WOTUS. You could even put in a pipe or culvert (because the wetland is so very wet…) and yet it’s no longer, legally, a wetland.

DSC_0119I encourage you to read the proposed Rule yourself, and/or those analyses linked above. And then, please consider weighing in with a comment on the proposed Rule. As you might expect, I plan to do so. This is a time we need to speak up. Our Government needs to know that we value wetlands (whether they do, or not). We must remind our public servants that whether a wetland is physically adjacent to a stream or not, it nevertheless DOES affect the hydrology of that stream. The wetland absorbs water that otherwise (even if by groundwater, rather than a surface connection) would contribute to downstream flooding. The wetland improves the water quality of the downstream WOTUS. So-called “isolated wetlands” simply aren’t isolated, and they do important work…but only if we allow them to exist!!

And beyond reacting to this specific government action, I hope we can think about the long-term future of our wetlands. Personally, I would like our Nation and its government to provide effective and uniform legal protection for all of our aquatic resources, including wetlands. I certainly believe in making that task as straightforward as possible for everyone  involved: landowners, regulators, and environmental professionals. How do we serve our citizens best? Protecting wetlands is surely part of that…so how do we get it done??

The Nitrate Commons

P1140132Over the past three weeks, we’ve visited a cluster of three northwest Iowa counties: first Calhoun (Twin Lakes WMA), then Buena Vista (Storm Lake Marsh), and last week it was Sac County (Kiowa Marsh). The center of that cluster is about 90 miles (145 kilometers) due northwest of the state’s capitol (and largest city), Des Moines. It might be more useful, however, to measure the river miles—how far water flows downstream from those counties. And therein lies the tale of a serious nitrogen pollution problem, recent legal action, and a glaring example of our collective environmental commons.

This concept of The Environmental Commons was explained by Garrett Hardin in a classic 1968 paper in the journal Science entitled The Tragedy Of The Commons. That article is about human population growth, but the premise of the Commons itself works for any shared resource. In the article, Hardin presents a parable of a shared grazing space (a village green), called The Commons, and presents the choice faced by any user of a commons (e.g., sheep herder):

…The rational herdsman concludes that the only sensible course for him to pursue is to add another animal to his herd. And another; and another… But this is the conclusion reached by each and every rational herdsman sharing a commons. Therein is the tragedy. Each man is locked into a system that compels him to increase his herd without limit–in a world that is limited. Ruin is the destination toward which all men rush, each pursuing his own best interest in a society that believes in the freedom of the commons.

The tragedy, of course, is that everyone acts rationally, until the Commons (shared resource) is “ruined” (depleted). Every user of the Commons only takes a little bit, and never intends to cause harm. And yet overall, harm is the result. This certainly has happened with overgrazing on shared public lands in the United States, a giant “village green” if you will.  However The Commons can be ANY shared resource, such as harvesting  from ocean fisheries. Little  by little, through innocuous individual actions, populations crash, and a shared resource (commons) is ruined.

dsc_0810Now, let’s think about water pollution. A common form of nitrogen (nitrate, NO3) is found in Iowa’s waters: rivers, lakes, groundwater. Its presence is normal and natural. Adding just a little bit from a pipe or through runoff over the land surface is to be expected, and not a problem. Organisms in ecosystems, such as found in an Iowa stream, can and will use/process/transform the nitrate. In fact, nitrogen is a fertilizer: it helps plants grow. This is not inherently a problem.

However—at some point, the individual contributions add up, and we collectively add so much nitrate that our water bodies become degraded. This affects the stream or lake ecology (they become “impaired” in the regulatory sense), and the nitrate flowing downstream joins the Mississippi River, where it eventually reaches the Gulf of Mexico. Down in the Gulf, it contributes to hypoxia, the infamous Dead Zone.

The nitrate problem isn’t just ecological, however. Some water suppliers draw from surface water bodies, or shallow groundwater connected to surface waters. Their customers will then drink the high-nitrate water. For example, the Des Moines Water Works supplies domestic (drinking) water to half a million residents in central Iowa. The Water Works draws from the Racoon River whose large drainage area (watershed) lies to the north and west. Nitrates within the watershed are carried to the river flowing downstream and then affect the water quality, raising levels of nitrates above the legal limit (10 parts per million of nitrate-N). Nitrate levels exceeding the limit happens several times a year, and forces the Water Works to use an expensive nitrate-removal process.

As a result of this added operating expense, the Des Moines Water Works then sued three public drainage districts located in upstream counties. Those are the counties featured in the last three weeks on this blog.

Note that nitrates are added to water in many ways: effluent from wastewater (such as septic systems or a city wastewater treatment plant), animal waste, runoff from farm fields or golf courses, and the very lawns at our residence—literally, our own back yard. They can all add nitrates, and they are all implicated in our common nitrate challenge.

The Water Works lawsuit was dismissed, and that isn’t surprising. Too large an area of watershed, with too many sources of nitrates, are contributing to the river’s water pollution—it would be quite difficult to assess damages against a few particular entities. The watershed, and its ability to safely process nitrates, is a shared resource–a commons. We all own it, we all are effected by it, and we all contribute to a common nitrate problem.

dsc_0168What then shall we do?? I believe there are three parts to this challenge:

First, we should have an honest conversation. It’s long past time pretending that no problem exists, or that it will solve itself. When I arrived in Iowa in 1998 and learned of ongoing legal battles about nitrates in water, I never dreamed we’d be fighting about it all these years later. We need to acknowledge the multitude of evidence, consult with the people who have worked hard on this problem, and commit to finding solutions.

Second, we must strategize about the possible solutions. Knowing how nitrates get into the water, and what acceptable levels (water quality standards) should be, we can talk about ways to account for the sources and how to reduce the inputs.

Third, we must implement well-planned measures to get the job done. This is where economic and political reality comes in—what strategies will be widely supported, and workable? What is cost-effective and achievable in a timely manner? We should think about buffer strips and cover crops, and better wastewater treatment, and bioreactors, and many other great ideas.

Oh…and wetlands. As discussed many times on this blog, wetlands “clean the water,” including removing nitrates. Preserving and protecting our existing wetlands, and building or restoring others, will surely help us save our Nitrate Commons. Let’s get to work!

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“Pond,” “Lake,” or “Wetland…?” Whatever.

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Pretty houses and cottages along North Twin Lake. A State Park with pavilion and restrooms is nearby, but no camping is available.

The Twin Lakes (North and South) of Calhoun County are a good example of the old question, “what’s in a name?” As a Limnologist–someone who studies water bodies on the continents: ponds, lakes, rivers, streams…and of course, wetlands!—I am sometimes asked how to differentiate between these systems. People want to know for example, when does a pond have sufficient surface area, or depth (or both?) to properly be called a lake?

For better or worse, there IS NO “official” distinction between these terms. (Really!) Suggestions involving the photic zone depth, or stratification, or minimum area…they are all attempts to be helpful, but are nevertheless always arbitrary. Here, someone decided that (likely in consideration of surface area), the Twin Lakes are each truly “lakes,” and of course the name reflects that. According to the Iowa DNR, North Twin Lake is deeper (ranging in parts to 12 feet/3.7 meters), while South Twin Lake is mostly between four and five feet (1.2-1.5 m) deep. South Lake is about a third larger in surface area, however (600 vs 453 acres/243 vs 183 hectares). In this part of the world, those are large enough to be considered lakes, and who am I to say otherwise?

DSC_0350Whatever name or category we choose, these are certainly shallow, productive systems (i.e., lots of algae or pondweed growing). That productivity will support a food chain and provide habitat for fish. But too much productivity makes murky water which is less appealing for swimming/boating/other recreation. A common question asked of any limnologist is “how do we reduce the algae/weeds in our pond/lake?” Of course, the answer is “stop fertilizing the pond/lake.” If you don’t want so much plant growth, don’t put silts/sediments, or growth-enhancing chemicals such as nitrogen or phosphorus into the water. Those chemicals increase the productivity of the green photosynthetic organisms—that’s why we consider them “fertilizer.” A nutrient and erosion control strategy is exactly the prescription for Twin Lakes proposed by experts from Iowa State University.

“But Paul,” you say. “Where do wetlands enter in?” Regular readers know that defining, delineating, and characterizing ecosystems are part-and-parcel of the wetland business, more so than other ecosystems. So, we are simply expanding our questions and checklists for “how to define a wetland” to use in ponds/lakes. Fair enough.

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Water flows from lands upslope (left) down to South Twin Lake (right)

More importantly, wetlands lie between the land and water. Ecologically, wetlands have characteristics intermediate between terrestrial and aquatic systems. Hydrologically, wetlands often catch runoff, located in a spot where they physically intercept water flowing overland towards a water body (like a lake!). Near the south shore of South Twin Lake, down-slope from farm fields and US highway 20, lies a classic “cattail marsh.” This wetland contains a large area of cattail (Typha) plants, with muskrats (Ondatra zibethicus) and a few willow (Salix) trees. The wetland surely catches runoff heading toward the lake, removing silts and nutrients. Wetlands really do “clean the water,” so visitors to the lakes and lakeshore residents benefit from the work done by the wetlands.

Over the coming weeks, we’ll visit another couple wetlands designed and managed to protect or improve water quality. Let’s think about the challenge of water quality of the specific lake or stream near those wetlands; also keep in mind that the challenge of water quality in Iowa, in particular a form of nitrogen in our waters, is bigger than any particular water body. We have to think bigger, and face some contentious issues. As always, I’ll do my best to explain it all in a straightforward manner…and I’ll have pretty pictures, too! I hope you join me for the journey.

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Willows, cattails, and Muskrat. Yup, that’s an Iowa wetland…

Construction Materials from the Marsh

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Open water among the ice cover attracted a Bald Eagle, doing a bit of fishing.

Are you interested in how people use plants for food, fuel, medicine, or other purposes? The study of plant use and associated human history and culture is called Ethnobotany, and it’s a topic of interest to me and my students. A previous 99wetlands post featured a few wetland plants eaten by people. And on a recent visit to Otter Creek Marsh Wildlife Management Area in Tama County, I thought again about plant use by humans…and by wildlife, too. In this post, let’s talk about wetland plants as a construction material.

In particular, marshes have a lot of grass-like (graminoid) plants growing up out of the water (i.e., emergent vegetation): examples at a place like Otter Creek often include Cattails (Typha), River bulrush (Bolboschoenus fluviatilis), Softstem Bulrush (Schoenoplectus tabernaemontani), true grasses, and so on.

Think about the challenges those plants face when growing here. Obviously, freezing in winter destroys tissues, so a die-back of everything above the mud is unavoidable. During the growing season, stems must be able to “go with the flow,” bending with the moving water, even including powerful wave action during windy conditions. Yet the photosynthetic stems and leaves must remain upright, out of the water, maximizing sunlight capture. In certain species, those aboveground parts connect to horizontal stems that are spreading through the mud, as well as to the roots. Those tissues in the anoxic (oxygen-free) mud have metabolism of course, and so must have oxygen delivered to them. So the emergent stems and leaves must access oxygen in the air up above, and deliver it down to the belowground tissues.

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Frosty Cattail in cross-section; spongy tissue has deteriorated

The leaf structure of Cattail shows solutions to these challenges. Even in winter, the leaves are remarkably sturdy, sticking up out of the ice (and they will persist through the next growing season). The leaves are more-or-less a cylinder down below, presenting less resistance to water movement; yet higher up, they spread out flat to act as efficient “solar panels.” In cross-section the leaf looks a bit like an airplane wing: hollow (saves on materials, and less resistance to wind/water forces) but reinforced with thin internal walls as supports; a spongy material fills in the voids. Even better, that internal structure forms a “snorkel,” allowing air (and oxygen) from from above to diffuse down to the plant parts in the mud.

That system allows cattails to grow, but the story doesn’t end there: those plant tissues prove useful to animals, as well. I saw several Muskrat (Ondatra zibethicus) mounds in the marsh, made of graminoids and Smartweeds (Polygonum) and other plants piled up, incorporating a little mud as a binding agent. The plant tissues are flexible and durable and even somewhat waterproof. They compress a bit, but not too much—great for mounding up. One mound was taller than I am, and formed an igloo-shape. It got me to wondering what it was like inside where the animals were overwintering. For example, does the mounded plant materials keep the muskrats warm??

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A large muskrat mound out in the marsh

To help answer that question, and thereby better understand the characteristics of the plant as a building material, I set up a little experiment back at the lab. I compared the temperature in the center of paper cups suspended above a heat source (60W incandescent light bulb). One cup was filled with dried, packed graminoid tissues; one cup contained fiberglass insulation (the material used to insulate the walls and attic of a house), and the Control cup remained empty (well, I suppose it contained air!). I monitored the temperature in each cup using both electronic and glass thermometers, observing the temperature change every couple minutes until it stabilized (about 30 minutes).

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Caution: Mad Scientist at work!

I expected a difference in “r-value,” with the fiberglass-filled cup  changing temperature most slowly, the plant cup a bit more quickly, and the empty cup changing temperature most rapidly. I assumed that since each cup was right above an identical (very hot!!) bulb, they would all reach the same elevated temperature soon enough. But…that’s not what happened, actually.

Instead, the temperature changed at about the same rate in each cup—maybe the insulation layer was too thin or the heat-transfer surface too narrow to be important in blocking the temperature change? However, the materials made a BIG difference in the final temperature achieved: the control cup increased temperature by 15 degrees Celsius (59 degrees Fahrenheit), the fiberglass changed 25 C/77 F, and the plant material really heated up—increasing by 32 C/90 F!! It’s been a while since I studied physics, but I suspect this is due to the different thermal mass of the materials. Plant tissues can absorb and store more heat energy than can fiberglass; and air itself has little heat-storage capacity. So, the plant material heats up.

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fresh snow reveals tracks of several animals

I wonder what all that means for the muskrats? Being “warm-blooded” animals, I suppose they huddle together down in that mound, sharing body heat. A mass of warm animals in a massive, heat-trapping home makes sense during a cold Iowa winter. They remain active throughout the winter, so their fur must be pretty good insulation, too…no wonder the fur is valuable to humans!

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The Meskwaki Settlement is located in Tama County

So, Muskrats find the plants to be a useful building material…but, so do humans! An interpretative display at the marsh describes traditional use of graminoids by the Meskwaki, a nearby settlement of Native Americans/First Peoples. The plants were woven into mats and incorporated into dwellings known as wickiups. We encountered this ethnobotany in a previous 99wetlands visit, to an interpretative nature center in Linn County. I’d love to learn more about traditional uses of plants (and other aspects of history & culture)…if you like, please leave a comment to recommend a reading or a place to visit, etc.

I think it would be fun to visit this site again, perhaps during a warmer season. Maybe I’ll watch the birds with the scope provided at the interpretative display. Till then, I’ll hunker down in my own cozy family dwelling, with an occasional wander out to the marsh. Please come back and read about my further wetland wanderings.

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A “bird’s-eye” view for bird-watching?

Battle of the Nest Boxes?

2cansI’ve been known to joke that a useful “wetland indicator” is the presence of wood duck nest boxes. These structures are quite ubiquitous! I’d say the only nest structure more common in wetlands than wood duck boxes, is the classic sawed-off blue-plastic barrel (platform nest for geese, etc.). Anyway, wood duck nest boxes are placed (singly, or multiples) on metal poles in the marsh, or on trees in the forested floodplain. And yes, I’ve seen them in use—they really do work.

So, I was not surprised when I saw several Wood Duck nest boxes at a wetland in Grundy County. I was visiting Holland Marsh which seemed a natural choice for a guy from Pella, an employee of Central College (Go Dutch!). What DID surprise me was the variety in styles of the nest boxes and their placement. A duplex of two different steel canisters sat atop a steel pole along a meander in the floodplain of Holland Creek (photo above). Fun facts I recently learned about such “boxes” include that they were originally developed right here in Iowa, at Union Slough—one of my 99wetlands! Also, the canisters are typically emptied Freon containers…something I’ll ponder next time I use my air conditioning.

Nearby, behind a long angled berm, is a constructed marsh. There I found the other common type of wood duck nest box: an actual wooden box! This one had slipped down its mounting pole, so I could examine and photograph it. A typical example of the style, it was tall, with a wire mesh inside provided to allow a bird (fledgling) to climb up and out when ready to leave the nest.  Although presently in disrepair, a box such as this can be reassembled and used again and again. But please consider the importance of keeping a nest box in good condition. Even a box appearing from the outside to be in perfect condition should be inspected and cleaned at the start of breeding season, and carefully monitored while in use. My observations suggest that too many nest structures (all over, not just in wetlands) are installed with good intentions but not subsequently maintained. An argument could be made that it’s counterproductive—a nest structure prone to predator or parasite problems might be an invitation to disaster for bird parents.

Kevin from the County Conservation Board suggested that perhaps the wood box is more popular with the ducks than the canister type—that seems to be the observations of others as well (see link above). In the battle of the boxes, old-school wood is still best! He also mentioned that routine maintenance of nest boxes is on the To Do list; hopefully that box gets on the schedule. As a cooperative of several conservation organizations (Pheasants Forever, Ducks Unlimited and Iowa Natural Heritage Foundation) work at Holland Marsh will have multiple objectives, in addition to promoting wood duck populations. I was delighted to hear, for example, that Blanding’s Turtles have been noted at the site.

I enjoyed walking around this wetland, enjoying its quiet beauty on a winter’s day. Thin, transparent ice showed the pondweeds beneath, and walking the berm provided a bird’s-eye view of the snaking, meandering Holland Creek. Although overcast, the wind was calm and a raptor soared around me, perhaps enjoying an even better bird’s-eye view. It’s fun to think about all the life still out and about, active all winter long. Perhaps I’ll find more of them…or their tracks, scat, and whatnot…in future wetland wanderings. I hope you’ll join me. Thanks for stopping by!Holland_hawk