Battelle Darby Metro Park
Battelle Darby Metro Park lies on one of Ohio’s two main rock bases: limestone. Western and northern Ohio is primarily composed of weak, easy to erode limestone, while southeastern Ohio is underlaid by difficult to erode sandstone. Due to limestone’s fairly weak resistance to
erosion, much of western and northern Ohio has been eroded into a flat plain, while southeastern Ohio has retained many sandstone hills interspersed with valleys eroded from weaker shale where it was unprotected by sandstone. Originally, Ohio’s rock strata was composed of a layer of sandstone, which capped layers of shale, and then limestone beneath it.
During the formation of the Appalachian mountains, these layers were forced into a low arch, pushing up in the north and western parts of the state, and pushing down in the southeast. The higher elevation western and northern parts of the state were subject to more erosion, exposing the old limestone layers which were then formed (along with the future valleys of the southeast part of the state) into a flat plane by the ancient Teays River system. The river system flowed for 200 million years, grinding down valleys into the sandstone and flattening the limestone, until advancing glaciers from the north stopped it less than a million years ago.
As these glaciers advanced and retreated many times, they quickly moved across the flat limestone of most of the state, but were drastically slowed by the sandstone hills in the southeast. This led to the exposed limestone portions of the state being glaciated, while the sandstone regions were left unglaciated, protected by their steep hills. When the glaciers retreated from glaciated areas, they left behind a substrate called
glacial till. Glacial till is composed of a mixture of clay, silt, sand , and boulders, and it picks up substrates from the areas it travels over. Due to this, glaciated areas received a nutrient rich substrate high in lime and clay, that is very slow to soak up water, leaving pools of water on the surface after rain. In unglaciated areas however, the sandstone becomes a low nutrient acidic, loose substrate that absorbs water quickly. This water flows into underground springs and then into the nearby valleys.
Due to these large differences in substrate, Ohio’s substrate-specific plants fall into three main groups: limey/thin substrate, high lime-high clay substrate, and acidic, sandy substrate. Some species in the thin, limey substrate are Blue Ash, Chinquapin Oak, Hop Hornbeam, Fragrant Sumac, and Hackberry. While most common in thin substrates such as the islands of Lake Erie, Blue Ash is also found often in much of western Ohio. This species is easily differentiated from other trees by the “boxy” outgrowths on their twigs. Next up is the Chinquapin Oak, which
is similar to the Chestnut Oak, except it is found in limey soils instead of acidic ones. Both species are very similar, aside from the differing soil requirements and the sharper leaf margins of the Chinquapin Oak. Third, we have Fragrant Sumac. This species is in the genus Rhus which is closely related to Poison Ivy. While it doesn’t look much like other sumacs (trifoliolate as opposed to pinnate leaves), Fragrant Sumac can occasionally be mistaken for Poison Ivy. The most obvious difference between the two is that Fragrant Sumac forms a bush, while Poison Ivy is mainly a groundcover or vining plant. The fruits of Fragrant Sumac are also red, while the fruits of Poison Ivy are white. Limey soils are also home to Hackberry, an elm-like tree that is usually distinguishable from elms by the discoloration of its leaves due to various plant ailments. Finally, there is Hop Hornbeam. Hop Hornbeam is a small tree found in the understory of limey substrate forests, and is identifiable by its elm-like leaves combined with scaly, flaky bark. While not pictured, some plants characteristic of the high lime, high clay substrates of western
Ohio are: Shagbark Hickory, Red Oak, White Oak, Sugar Maple, and Beech. Also not pictured are several plants found in sandy, acidic sites (see Deep Woods page): Chestnut Oak, Mountain Laurel, Sourwood, Huckleberry-Blueberry, and Eastern Hemlock.
Several species characteristic of acidic, sandy substrates have different underlying reasons for their limited distributions in Ohio. For example, Yellow/Sweet Buckeye and Eastern Hemlock. Within Ohio, the Yellow Buckeye’s native range is entirely within the unglaciated southeast, and doesn’t even extend into the northern range of the unglaciated region. This is possibly due to a mix of repopulation and climate issues, with the plant struggling to establish in high lime, high clay soils, and climate preventing its spread into the northern portions of the unglaciated region. Meanwhile, Eastern Hemlock is found both in unglaciated southeast Ohio and the formerly glaciated northeast Ohio. The reason for this stark contrast in substrate across its distribution is much clearer than that of the severely limited distribution of the Yellow Buckeye: Eastern Hemlock trees are only found in cool, moist valleys. In the southeast of the state, these are eroded valleys between sandstone hills, and in the glaciated northeast, they are river valleys between glaically-deposited gravel hills. There is even a known population locality in the western portion of Ohio, where Eastern Hemlock trees are nestled into a river-carved gorge that a member of Daniel Boone’s party leaped across while fleeing from Native Americans, at least according to the local folklore (Louderback). While there’s no way to know today whether this famous leap really occurred, it’s possible the drooping branches he grabbed onto, which prevented him from falling into the rushing water below, were those of an Eastern Hemlock. Finally, there is the range of Rhododendron. Rhododendrons have a very limited range in Ohio, which is solely in a few spots of the unglaciated region. Their range is initially confusing, until compared with the river-carved valleys of the ancient Teays system. It is thought that Rhododendrons (primarily an Appalachian plant) utilized the river to spread into ancient Ohio. Once glaciers invaded and smoothed out the Teays system in the glaciated regions of Ohio, the Rhododendrons were left stranded, unable to spread any further.
Cedar Bog (That Isn’t A Bog)
Cedar Bog is in a unique position in Ohio. A glaciated portion of the state that was (somewhat) spared from the bulldozing glaciers that helped flatten large portions of western Ohio. As the glaciers moved south, they hit Bellefontaine, Ohio’s highest point. The hills in this area were hard to push through, causing the glaciers to move around instead, leaving hills called end moraines that mark the edge of the glacier’s extent. These gravelly hills create a high point for rainwater to flow down from, eventually ending up in the Miami River or an underground aquifer. Normally, the aquifer is capped by clay substrates in low areas (such as the Miami) which prevents it from joining the river system. However, in a few spots, there are holes in the clay layer, which are filled with porous gravel instead. In these low, close to the water table spots, the underground aquifer flows straight from the limestone bedrock to the surface. As the underground limestone dissolves into the aquifer, and that water runs to the surface, it becomes alkaline and forms a fen. The poor, gravelly substrate of a fen generally prevents woody plants from growing there, and fens are filled with many low-lying, specialized plants instead. As these plants die and build up, they can form a substrate for woody plants, such as Northern White Pine, to grow on instead. Nearby, Cedar Bog (fen) flows into a swamp forest, which is fed by the aquifer-cooled water of the fen, and creates an environment perfect for many water loving plant species, such as tuliptrees, to grow.
Many species we saw in the fen have a high Coefficient of Conservatism, which is a measure of how similar an area is to pre-European settlement by the plants that are found there. Plants that are generally only found in highly conserved areas receive a higher score in the system (~7-10) while plants that are found even in highly disturbed environments receive a low score (~0-3). Unsurprisingly, since Cedar Bog is well managed as a preserve, we were able to find a lot of plants with high CC scores. While we found many plants with high CC scores, here are a select few.
One example is Ohio Goldenrod. Before this field trip, I had no idea that Ohio had it’s own goldenrod species (named, not endemic), and I also learned that Ohio Goldenrod is characteristic of highly conserved areas, with a CC of 9. We also saw Swamp Lousewort. Swamp Lousewort is an inconspicuous, hemiparasitic plant with a CC of 8. The final two high CC plants I chose to feature are Grass of Parnassus and Kalm’s Brome. These
are fairly small flowering plants that are about as easy to miss as Swamp Lousewort if you’re not paying attention. Kalm’s Brome has a CC of 8, and Grass of Parnassus has a CC of 10! Just goes to show the value of paying attention to and learning about the landscape around you. Walking through a habitat you’re informed about is a lot more interesting and fun than one you know nothing about, or assume is “normal” or boring.
Individual Assignment:
This time around, my individual assignment was to document two plants
with animal interactions. This was a pretty easy assignment for me, since plants are interacting with just about everything, especially insects! The first plant animal interaction I saw was pointed out by Dr. Klips at Battelle Darby. It was a Hoptree bush! Hoptree is a shrub or small tree with trifoliolate leaves, and can often be mistaken for Poison Ivy (minus the fact that it’s a shrub, not a vine). Combined with its shrub-status, Hoptree’s trifoliolate leaves with smooth margins distinguish it from Poison Ivy and Smooth Sumac. While we didn’t see any catterpillars on the bush, Hoptree is a host of the Swallowtail Butterfly! Interestingly, Hoptree’s name comes from its fruits former use as a alternative to hops in brewing (Johnson). The other plant with an animal interaction I chose to feature was a Pasture Thistle. This is a common plant, not restricted to fens or wetlands, although this one was in a wetland at Cedar Bog. It is easily identified by its large, mostly-spherical receptacles, and its spiky leaves. At the time of taking the photo, the Pasture Thistle was being pollinated by a… bumblebee? leaf-cutting bee? digger bee? butterfly??? Much to my dismay, my bee identification skills are severely lacking. If not for the fact that we were in Cedar Bog, I would have grabbed a specimen for later identification. Later, I learned that Pasture Thistle has a specialist pollinator species, which is a type of mining bee (Illinois Wildflowers). Had I known this at the time, it would have made a potential identification even more interesting!
Extra Photos (Scenic Landscapes and Rare Roses):
Louderback – https://www.jefflouderback.com/spring-at-clifton-gorge-darnells-historic-leap-etched-in-history/
Johnson – https://www.wildflower.org/plants/result.php?id_plant=PTTR
Illinois Wildflowers – https://www.illinoiswildflowers.info/prairie/plantx/ps_thistlex.htm