Prairie Fen Series – Recognizing a Fen Neighbor

Welcome back to our prairie fen series! The first post took a broad look at what prairie fens are and why they exist. In this post, we will focus on key plants that act as indicator species for a prairie fen community. Using mostly pictures taken from our township’s own fens, we will also dive into the vegetation zones that characterize these unique habitats.

I have been fortunate enough to visit each prairie fen in our township parks. I am always amazed by the diversity of plants I find at each of these sites. I started this series because I had little knowledge of what a prairie fen was, and no idea that I lived among them. Unlike other wetlands, I found that prairie fens blend extremely well into the surrounding environment. Maybe this is why I and so many others were estranged from these fen communities that are my close neighbors here in southern Michigan! A fen could be right under your nose in your local natural area or even your backyard! I hope this post may guide you if you hope to get acquainted with the wondrous prairie fen.

Our prairie fens

We have three prairie fen habitats in three different parks. Each site is unique with its own plant community, land use history, and threats.

We have prairie fen habitat in three of our township parks: Draper Twin Lake Park, Paint Creek Heritage Area – Fen, and Fox Nature Preserve. The plants that have greeted me at these prairie fens ranged from recognizable prairie and wetland species to more specialized flora able to survive in difficult environments. With their unique conditions, prairie fens are biodiversity hotspots for plants, animals, and insects in Michigan.

As the book Exploring the Prairie Fen Wetlands of Michigan states, prairie fens typically support twice the plant species found in bogs. Although both fens and bogs exhibit difficult growing conditions, with pH ranges in the extremes, fens exhibit a wider diversity of vegetation types. My last post gave us an important clue to why this is: fens are fed by groundwater seeps. Not all parts of the fen get equal volumes of calcium-rich water, resulting in different growing conditions and different sets of plant species in each fen zone.

Even the topography of a fen depends on the flow and composition of groundwater. Wetlands are usually associated with depressions in the landscape. However, prairie fens can be found as domes within a wetland, on slopes, and in low-lying areas along lakes and streams. Basically, wherever calcium and magnesium-rich groundwater percolates to the surface in southern Michigan, there could be a prairie fen!

When identifying a prairie fen, do not exclude areas that form a mound or on a slope. Figure from Exploring the Prairie Fen Wetlands of Michigan

Other conditions such as peat accumulation and disturbances, both natural and human-caused, can play a role in fen vegetation types. According to Michigan Natural Features Inventory (MNFI), these zones in a fen may include wooded fen, sedge meadow, marl flat, and inundated flat. As reported by the Michigan DNR, the sedge meadow is typically the largest part of a fen, while the wooded fen is found in slightly elevated uplands around the edges. Historically, naturally-caused fires and those lit by Native Americans would burn into prairie fens and maintain a more open structure. Today, the wooded fen may occupy more of the fen and the sedge meadow less due to fire suppression throughout Michigan.

The four vegetation zones of prairie fens. Note that the prairie fens in our parks are not large enough to have all of the four vegetation zones present. All photos are from our township prairie fens except the marl flat, which was taken in Springfield Township.

Prairie fens can look different from one another depending on hydrology, topography, and fire history, so it may be tricky to determine if a wetland is a prairie fen. Luckily, we can use certain plant species as fen “indicators.” Prairie fens have high pH levels due to the calcium and magnesium carbonates in the groundwater, and some plants are only found in these calcareous conditions. Identifying these specialized “calciphile” plants would bring you to a prairie fen classification without having to identify each plant species in the community. However, the lower the habitat quality, the more difficult it is to determine if a habitat is a prairie fen remnant since cattails and other generalist wetland plants typically increase in abundance after disturbance.

The Michigan State University Extension resource on fen evaluation is helpful for all levels of habitat quality. They recommend surveying in late August and early September when many of the calciphilic species are in bloom. Some of the species listed below are calcium-loving, while others occur both in fens and a variety of other wetland types. Continue scrolling to see prairie fen indicator species found in each of the vegetation zones.

Wooded fen

Larix laricina – Tamarack

Eastern Larch, also known as tamarack, is a conifer that breaks all the rules. It is a deciduous conifer that also prefers to grow in the toughest conditions. Tamarack trees are often indicators of all types of peatlands, no matter the pH, but can grow in other wetland types too. Soon they will be turning bright yellow and will eventually lose their needles. The clusters of needles on short shoots that form firework-like sprays from the branches distinguish tamaracks from other conifers in Michigan.

Toxicodendron vernix – Poison Sumac

Similar to tamarack, poison sumac can be found in both acidic and calcareous wetland soils, mostly in southern lower Michigan. I often find that the leaflets of the compound leaves point upwards to the sky. Poison sumac has light gray bark and is less “twiggy,” or finely branched than many other trees and shrubs after it drops its leaves. The photo above (right) shows the awesome fall colors that they will change into. Poison sumac may also be found scattered throughout the sedge meadow zone. Note that species may overlap in several vegetation zones.

Sedge meadow

Parnassia glauca – Grass-of-Parnassus

Grass-of-Parnassus is not a grass, although the smooth stem does tend to blend in with the surrounding grasses. This flower also has nothing to do with Mount Parnassus in Greece. Grass-of-Parnassus is only found in calcareous conditions, making it an ideal fen indicator species.

Pycnanthemum virginianum – Virginia Mountain Mint

Not sure why the common name has mountain, however, the mint part of the name is very suitable. If you are not sure about the ID of a mint, look for the square stem and rub a few leaves between your fingers. Most mint species have that characteristic aromatic fragrance. Common mountain mint occurs in wet meadows like a prairie fen but is not specific to fens. If you look closely at the flowers they are speckled with purple.

Ohio Goldenrod and Riddell’s Goldenrod

Ohio goldenrod (Solidago ohioensis) is easy to identify by its lower, rosette leaves that get quite large, have one central vein, and are flat. The upper stem leaves do not get as big as the lower leaves. The leaves of Riddell’s goldenrod (Solidago riddellii) fold inward like a paper airplane and taper to a point at the end. They have three veins obvious near the base of the leaf blade. Both species have a flat-topped inflorescence and are calciphiles, meaning they are adapted to calcareous soils.

Marsh Bellflower and Kalm’s lobelia

Marsh Bellflower (Campanula aparinoides) on the left and Kalm’s lobelia (Lobelia kalmii) on the right are both calciphilic species that can easily be overlooked among the larger species in the sedge meadow. It is worth crouching down to see these delicate flowers.

Dasiphora fruticosa – Shrubby Cinquefoil

I see this shrub everywhere in residential landscaping. That being said, it is naturally found in alkaline soils and is an indicator of calcareous conditions. In Michigan, it is mostly found in high-quality wetlands.

Rhamnus alnifoliaAlder-leaved buckthorn

Alder-leaved buckthorn is our only native buckthorn and is generally a calciphile found in high-quality wetlands. Although they are a good indicator of prairie fens, they can be tricky as they look similar to their invasive relative; common buckthorn. I can tell the difference as the leaf tips are more pointed than common buckthorn, and the leaf veins more prominent.

Bog Birch and Sage Willow

These low-lying shrubs are great indicators as they tend to stand out and are easy to identify. Both bog birch (Betula pumila) on the left and sage willow (Salix candida) on the right prefer calcareous soils. Bog birch has small oval-shaped serrated leaves while sage willow has striking white-hoary leaves.

Inundated flat

This vegetation zone can be found on the edges of lakes or streams and is dominated by various sedges and rushes. Sedges and rushes are typical in inundated flats and are super cool, but since they are not easy to identify we won’t discuss them in detail here. The Fox Nature Preserve fen is the only prairie fen in our parks with an inundated flat.

Marl flat

Marl flats have strong groundwater seepage and are therefore highly alkaline. Due to the high pH, only species adapted to extreme conditions can survive and the flats are sparsely vegetated. Our township’s prairie fens do not contain marl flats.

Marl flat landscape was taken at Shiawassee Basin Preserve in Springfield Township.

Cypripedium candidum – White Lady’s Slipper

Marl flats contain the most radical plants from rare orchids to carnivorous species such as sundew and pitcher plants.

The most rewarding part of this season was finally being in on the secret of prairie fens. Now that you have been acquainted with some botanical residents of prairie fens, I hope these communities are no longer strangers. To protect imperiled ecosystems I believe we first need to be able to recognize them as fellow neighbors. Only by understanding its parts can we understand the needs of the community as a whole.

Stay tuned for the final post in the series! We will broaden our lens and discuss human-caused threats prairie fens are facing, and what our stewardship team is doing to help.

Prairie Fen Series – Meet our Dynamic Peatland!

Take some time to learn about Southern Michigan’s most underrated ecosystem, the prairie fen! In this three-part series, we will go over what a prairie fen is, how to identify this community by its plant species, and what threats they face. This first post offers a reflection on these globally rare, but locally abundant, biological treasures by comparing them to their more well-known cousin, the bog. We will start the series by looking at the geological events that formed these unique wetlands using photos and stories from Michigan’s largest prairie fen. Stay tuned for two more posts all about our Township’s own prairie fen plant species and its history of being overlooked.

Peatlands: Bogs and Fens

Wetlands have received a lot of hype recently due to their capacity for preserving biodiversity and mitigating climate change. According to the International Peatland Society, the majority of our world’s freshwater wetlands are composed of peatlands. Most peatlands are classified as either fens or bogs. The saturated, anaerobic (no oxygen) soils of these special wetlands do not allow rapid decomposition of plant matter, allowing net accumulation of peat over time. As a result, peatlands are the largest terrestrial storage for carbon, according to the International Union for Conservation of Nature (IUCN).

Although both peatlands are adept at producing incredible biodiversity and carbon storage, they do not receive equal attention. I’ve noticed that even among my science-driven peers, fens are not as well-known as bogs. In undergrad, I was taught more about bogs than fens. Perhaps because bogs are more widely distributed and occur more frequently in Michigan. Or possibly because the highly acidic conditions (low pH) of bogs make them a more singular group, while the fens have several different subtypes. In college, I remember briefly learning that fen wetlands were fed by alkaline (higher pH) calcium and magnesium-rich groundwater, and bogs by rainwater.

Expanding my knowledge of the wondrous prairie fen

In Michigan, the fen group is made up of five natural communities, including prairie fen (check out coastal fen, northern fen, poor fen, and patterned fen if you’d like to learn about the other fens). Prairie fen is appropriately named since it shares many plants found in nearby tallgrass prairies. Prairie fen is found only in the Midwest, thanks to our mighty glaciers.

Map of lower Michigan’s glacier lobes in the most recent glaciation. The Wisconsin glaciation ended around 11,000 years ago. Image is taken from 2015 geomorphic study of the southern Lower Peninsula.

In Michigan, prairie fens primarily occur in the two interlobate regions of the southern Lower Peninsula. We have one interlobate region on the west side of the Lower Peninsula, and other interlobate region called the Jackson Interlobate here in the southeast region. These regions have a complex array of hills and valleys caused by the consolidation and withdrawal of glacier lobes during the Wisconsin glaciation. As noted earlier, all fens are fed by spring water. In the hilly landforms of the Jackson Interlobate, gravity pulls water down through the glacial deposits rich in calcium and magnesium. The alkaline water eventually flows down to the bases of slopes, showing up as spring-fed fens.

A figure displaying fen hydrology from Exploring the Prairie Fen Wetlands of Michigan by MNFI/Michigan State University Extension.

The calcium-rich, alkaline groundwater can be a tough environment for plants. A special set of plants that we call fen “indicator species” tolerate these harsh conditions better than general wetland plants. When we find these plants we know to look closer to see if the surrounding wetland is indeed a prairie fen. Tune into the next blog post in this series to learn more!

Map showing the distribution of prairie fens in Michigan. Circled in red is a cluster of fens that includes those in our township. The northwestern part of Oakland County is where Michigan’s largest prairie fen resides in Springfield Township. Figure from the 2009 Mitchell’s Satyr Habitat Conservation Plan.

My First Fen Visit

No amount of diagrams and reading can prepare someone for what a natural community is like until you are standing in one. I finally had the chance to experience a Michigan fen during the Eastern Massassauga Survey our crew helped with earlier this summer. The survey took place in Michigan’s largest remaining prairie fen in Springfield Township! On the drive there, my unconscious bias predicted the habitat to look similarly isolated and alien as an acidic bog.

I could not have been more naïve. In stark contrast, the landscape was alive and coherent. As I stood unstably on sedge mounds, I could hear what sounded like the thirsty noise of draining a bath. Only in the plants parted could I see where the peculiar sounds were coming from. Calcareous spring water, cold from being locked in the dark earth, ran in rivulets beneath us as we walked. There were also areas where streams flowed on top and through the vegetation. Water and earth weaved in and out of each other; I quickly realized that fens are interlaced with the rest of our sculpted landscape.

This picture depicts the seamless progression from prairie fen to oak forest.

Unlike bogs, which similarly occur in depressions caused by melted glacier ice, prairie fens are not isolated pockets of water. These fens are often part of larger wetland complexes, often occurring on the edges of lakes or along streams. Prairie fen’s plant communities often also morph into surrounding environments like oak barrens and openings, even sharing the same historical need for fire disturbance.

Leaving Springfield’s fen, I rejoiced in the never-ending surprises that come with being a student of the natural world. I had no idea a peatland could feel so energetic. I had been under the impression that all peatlands were as dead as their layers of preserved organic matter.

The next post in this series will dive deeper into the dynamic life that these fens sustain using flora and fauna snapshots from our prairie fen along the paint creek trail. In the meantime, you can check out a previous blog about the Unique Wetland Communities Along the Paint Creek Trail to get some background on the work we do there.

What the Turtles Taught Me

During my first month working in Oakland Township Parks, I was rewarded by the sighting of three Blanding’s turtles! These creatures seemed assured in my presence; their heads stuck out of their shell gallantly with a smile. I inched closer to get a better look. 

Two of the Blanding’s Turtles (Emydoidea blandingii) I saw during my first month at the parks. The left turtle was at Bear Creek Nature Park and the right at Watershed Ridge Park.

To my astonishment, they didn’t startle as I moved toward them. It was like their mind was elsewhere, and I left with envy at their mellow state. I admit I rarely experience a blank, light consciousness. In modern times, information is infinite and often a click away. There is so much to process at all times, that it is too easy to get lost in the constant happenings. In the presence of the smiley turtle, I saw the possibility of a different existence.

Turtles are the oldest living reptiles, even older than dinosaurs. Not only are turtles evolutionarily archaic, but they also have lifespans similar to humans: In 2016, a recaptured Blanding’s Turtle near Ann Arbor was believed to be 83 years old! Standing a short distance from them, their detached calm radiated onto me. This species, like so many others, is under threat and is currently listed as a species of special concern in Michigan. They take 14 to 20 years before reaching sexual maturity and have large home ranges (both wetland and upland). Yet, on my early visits to the parks, there they were. Obviously, humans are not turtles. They don’t have to pay rent and taxes or check their email. But that doesn’t mean they can’t teach us how to live on Earth. They have, in fact, been around the sun longer.

Snapping turtle (Chelydra serpentina) laying eggs last week at Gallagher Creek Park.

Lucky for us, Michigan is in the center of the Blanding’s range. According to the Michigan Natural Features Inventory, Oakland County has the highest occurrence of Blanding’s turtles in all of Michigan.  Keep an eye out for a domed shell and bright yellow neck that is characteristic of a Blanding’s turtle. You can report a rare species observation here https://mnfi.anr.msu.edu/species/report on Michigan Natural Features Inventory’s website.

Because we are in late spring, you are most likely to see female Blanding’s and Snapping turtles. They may be crossing roads, trying to find areas to nest. If you are fortunate enough to witness a Blanding’s turtle laying eggs on your property, you could build even build a nest protector to ensure hatchling success! See https://www.nohlc.org/install-a-turtle-protector.html for instructions. These would need to be checked daily so hatchlings do not get trapped. If you see a turtle on the side of the road and it’s safe, move them to the side of the road they are facing. After you’re done, maybe stand a short distance away and stay in their company. Who knows, you may just learn something.

Sharing those moments with the turtles, I now understand their influence. Without language or expression, I could feel their sureness. I picked the invasive garlic mustard near them and worried that my conservation efforts were never going to be enough. Seeing these turtles whose lineages have remained mostly unchanged, I am reminded to take a moment outside myself. It’s a constant inner battle to exist with the same assurance as those turtles.

Like the turtle, my existence spans past space and time, and yet as humans, we are caught in our own self-made troubles. These long-lived, traveling species are not equipped to cross a busy road. Neither are they able to protect their nests from the increasing urban predator populations. Therefore, this species’ life history is at odds with the increasing urbanization and fragmentation caused by us. Their very presence should be a lesson to see that there is a vastly complex world that should not be ignored. As long as we continue to have turtles as neighbors, we can be reminded that life is bigger than ourselves.

Meet Camryn: My Journey to Stewardship

We’re excited to welcome our 2022 seasonal stewardship crew! Camryn Brent, Cassie Stitzman, and Emma Campbell joined us in the last few weeks and will be out in the parks doing much-needed ecological restoration work until the end of the summer. Since starting they’ve been busy completing training, pulling garlic mustard, and getting ready for the season. Camryn Brent shares her introduction in this post, so keep reading to learn about the unique background and skills she brings to our team. Look for posts from Cassie and Emma soon. Drop a comment to help us welcome them to Oakland Township!

-Ben

When people ask me how I became interested in conservation work I usually give a simple shrug and say I always felt drawn to animals. My oldest core memory was driving with my mom down Woodard to the Detroit Zoo, strapped in a car seat. My siblings were older, so when they were away at school my mom would take me to the zoo whenever she could. About twice a week, whenever my mom wasn’t running errands, we would steal away to our favorite place. 

Oddly, I don’t remember actually being at the zoo that well. Instead, I vividly remember feeling uncertain looking out the window at the urban landscape. I didn’t understand the contrast from the animals in the zoo to the cement roads and store fronts. A lot of my childhood I spent in my head playing out a life in the animated world of Disney’s Lion King. I felt safer in my head then staring out an alien landscape, devoid of my beloved African animals. 

Young me staring wistfully out of the car window as the world flew by

As I grew older, I began to piece together an understanding that people and animals often didn’t coexist because of the ways of human civilization. I still loved animals, but my ingenuous wonder at the natural world was pushed down. In high school I remained environmentally driven, which led me to enroll in the Fisheries and Wildlife major at Michigan State University. My first year away, my 18-year-old self broke down and I considered dropping out.

After that horrible first year I knew I couldn’t spend a summer at home or else I would never go back. I enrolled in two semesters of summer classes at Kellogg Biological Station (KBS). There I began to rebuild myself into the conservationist I am today. Surrounded by a community of ecologists, with most of class time spent in natural areas, I became acquainted with organisms I had originally relegated to background noise. Plants, insects, birds, and even mushrooms became new friends. Through the iNaturalist app, I could call them by a name. 

Spending time with a patch of Wild Lupine while attending KBS

When autumn rolled around, I realized I felt clear headed for the first time in my life. I felt a connection to the land and all the living things that inhabited it alongside me. Most importantly, I realized that people can be stewards to the land. That people could curate biodiversity around them, not just destroy it. I have been riding on a sense of wonder and hope ever since that summer. It’s now been a year since I graduated from undergrad and three years since my time at KBS. 

I am currently back living at home with my parents and my fourteen-pound cat, Billy. I view metro Detroit a lot differently then when I grew up. I enjoy learning about the land pre-European arrival, and also about the bustling city my great grandparents immigrated to. I like to listen to the history of both the people and land, and try to foster a healthier future with both in mind. I’ve come a long way from the little girl without a sense of place, yet I’ve retained my curiosity and awe towards nature. I now know I will always find community as long as there are natural spaces to explore.

Current me on a prescribed burn at Paint Creek Heritage Area -Wet Prairie along the Paint Creek Trail

Since I’ve begun working at Oakland Township, I have been able to appreciate the natural areas stewardship program’s ability to create a common wealth of folks, old and young, ready to learn and take action. With my past seasonal experiences, I realized that restoration and management efforts suffer without the backbone of the public volunteers and nearby residents. For this reason, I am grateful for the opportunity to work with a township that engages its residents in long-term safeguarding of its natural areas.

Hope to see you on the trails!