Our class field trip to Cedar Bog proved to be packed with rare and unique plants and environments. Cedar Bog, unlike its name suggests, is actually a fen, meaning that water leaves by flushing; in contrast, water primarily leaves a bog through evaporation. Cedar Bog is especially interesting, because giant limestone deposits are found deep below its surface. Some of this limestone dissolves into the groundwater, which then bubbles up to the surface. As a result, Cedar Bog is home to some special plant species that thrive in its mineral-rich waters.
While hiking through Cedar Bog, I identified two plant species that are invasive to Ohio:
Common privet is native to Europe and Asia, and it is considered an invasive species in Ohio. It can be recognized by its opposite ovular leaves and dark purple fruits. Part of the reason it poses such a threat to local flora is because it is resistant to a wide range of conditions. Privet tends to forms dense thickets that reduce the amount of soil and sun area that native plants have access to. The severity of its threat to native populations is evidenced by its tolerance of the alkaline conditions of Cedar Bog and its ability to thrive here over other native species (Invasive Plant Atlas).
Amur honeysuckle is another invasive plant that is threatening local biodiversity. Native to Asia, it can be identified by its opposite branching pattern, white flowers, and red berry-like fruits. Much like privet, Amur honeysuckle reduces space for native plants to grow, and its fruits persist long into the winter. Many birds like to feed on these fruits, which the plant can start producing at just 3 years old (Invasive Plant Atlas).
Yet another interesting discovery I made at Cedar Bog involved some very rare plants with high coefficients of conservation (CC). Here are a few that I documented:
The CC value of these plants indicate that they are all very rare, and therefore must be conserved. It was quite astonishing to see so many rare plants on this field trip, and I certainly understand now why Cedar Bog is such a valuable and unique area.
“Amur Honeysuckle.” Invasive Plant Atlas. https://www.invasiveplantatlas.org/subject.html?sub=3040
“European privet.” Invasive Plant Atlas. https://www.invasiveplantatlas.org/subject.html?sub=3036
Batelle Darby Metro Park and Geobotany
Ohio’s geology can be broadly divided into two sections. In the west, limestone dominates underneath the soil. Limestone is quite weak, and as a result, erosion has left western Ohio largely flat. Alternatively, in the east, the more durable sandstone dominates, alongside pockets of weak shale. As a result, eastern Ohio displays many hills and caverns. Originally, sedimentary rock in Ohio was layered with limestone at the bottom, shale in the middle, and sandstone at the top. The same forces that created the Appalachian Mountains further east split these rock strata into an arch. The peak of the arch was located around western Ohio, while its toe was located in the east. The erosion of this arch can be largely attributed to the Teays River and its tributaries, only coming to a stop upon the advance of glaciers during the Ice Age. When these glaciers arrived, their progress was slowed greatly by the steep sandstone cliffs in eastern Ohio, but they had no trouble moving through the more delicate limestone plains of western Ohio. Thus, the deposition of glacial till – a mixture of sand, silt, clay, and boulders – also differed between the two regions. Glacial till in the west contains much more lime and clay than that in the east due to erosion of limestone.
As a consequence of these conditions that shaped Ohio’s geological landscape, plants growing in each region have different preferences in substrate. In western Ohio, soil is limey and dense with clay, with poor drainage and low oxygen content. In eastern Ohio, soil is acidic and has little nutrients, but moisture and aeration are better. On our trip to Batelle Darby Metro Park and Cedar Bog, I observed a few plant species that are adapted to the limey conditions of western soil:
Some other plants that are limited to limey substrates are hawthorn (Crateagus mollis), sedge (Carex eburnea), flat-stemmed spike-rush (Eleocharis compressa), snow trillium (Trillium nivale), and herb Robert (Geranium robertianum). On the other hand, some plants that are limited to the sandstone hills of eastern Ohio are chestnut oak (Quercus montana), scrub pine (Pinus virginiana), hemlock (Tsuga canadensis), greenbrier (Smilax glauca), and pink ladies’ slipper (Trillium erectum). For some species, distribution varies in a more complex way. Hemlock is distributed in unglaciated eastern Ohio and farther north, indicating that temperature and moisture is more important to its survival than substrate. Sweet buckeye does not extend its distribution outside of the glacial boundary, possibly due to limitations in temperature tolerance. Rhododendron is distributed south of the glacial boundary, and it is theorized that this is the result of migration down the preglacial Teays River.
Forsyth, Jane L. 1971. “Linking Geography and Botany… a New Approach.” The Explorer (13): 1-7.