Geobotany & Battelle Darby
Battelle Darby Metro Park
Geobotany of Ohio:
Before we begin I want to make sure we are very clear about what geobotany means. Jane L. Forsyth wrote an article titled, “Linking Geology and Botany… a new approach.” In her article she defined geobotany as the study of the relationship of plant species and plant communities with their associated substrate. Let’s dive deeper into what geobotany looks like in ohio.
Ohio can be split into two very distinctive parts. First we are going to talk about the western part of Ohio and then we will move on to the eastern part of Ohio. The western part of Ohio is underlain by limestone. So you may be wondering, what is limestone? Lime stone is a rock type that is relatively nonresistant and its humid climate. This means that erosion of the rocks first began millions of years ago. This part of Ohio has been worn down to a comparatively flat landscape. Ok, now let’s talk about the east part. Eastern Ohio is underlain predominantly by sandstone. Sandstone is a relatively resistant rock which is underlain by shale to the west. Erosion of the sandstone is accomplished mainly by solution of the natural cement holding the grains together by water seeping down through the rock. The process of dissolving the cement goes on very slowly giving the rock its resistant character. Shale is much less resistant, being worn down to low plains everywhere except where it is capped by the sandstone. As you may have guessed eastern Ohio has succeeded only in carving out deep valleys. Because of these deep valleys the landscape of the eastern part of Ohio is steep-sided sandstone hills.
The reason for the contrast and the different kinds of rocks present in Eastern in Western Ohio is actually relatively simple to understand. The horizontal sequence of sedimentary strata in Ohio is a thick series of limestone layers overlain by shales which were in turn overlain by sandstones. This horizontal sequence was gently tilted into the form of a low arc before erosion began. This arc is a part of a product of those pressures which began millions of years ago which created the original Appalachian mountains to the east. Erosion has cut deepest where the arched highest is in the west. As you may have guessed limestone is found throughout Western Ohio and it is very nonresistant. The arch is lowest in the east and that is why much more sandstone is remaining. We want to understand why this erosion occurred though. Have you ever heard of the Teays (pronounced “Taze”) river? Until now I hadn’t heard of it either! This river was present for a very very long time, 200 million years. Erosion was happening for so long until something appeared, the glaciers of the Ice Age (Good movie by the way you should watch it).
When these Pleistocene glaciers invaded Ohio they were slowed down by the steep sided sandstone hills of eastern Ohio. So this means that the glacial boundary there is no farther south than the latitude of Canton, Ohio. In contrast, the broad limestone plains of western Ohio have nothing to hinder the advance of the ice. It extended as far south as northern Kentucky! I will include a picture of a map of Ohio where you can see the glacial boundary.
Deposits by the glacier was of two kinds. There was an unsorted mixture of sand, silt, and clay and then boulders called till accumulated directly by the melting of the ice in the sand and gravel materials deposited by the glacial meltwater. and western Ohio the glacial till is rich in Like and clay while the till of eastern Ohio contains very little lime and clay, although near the margins of the area of Sampson Hills Hotel is higher in both lime and Clay than it is elsewhere in eastern Ohio.
On the plains of western Ohio the most common substrate is limy, clayey till which provides a relatively impermeable soil. The pH is limy and not as acidic as compared to the east. In the eastern Ohio the sandstone bedrock is very permeable where it is exposed; it produces a very acidic low nutrient substrate which is essentially dry on the tops of the hills. Locally, the sandstone crops out at the lower elevation. Although it is acid it provides a supply of moisture which is continuously available and cool. The water has percolated down through the permeable sandstone and emerged deep in the valleys without it being sun warmed.
So far you have done a lot of reading, but this part is interesting bear with me! Let’s apply this information we have learned to real life examples!
5 species of trees/shrubs that have a distribution generally limited to limestone or limey substrates:
- Eastern Redbud (Cercis canadensis)
- Red-Cedar (Juniperus virginiana)
- Hop Hornbeam (Ostrya virginiana)
- Hackberry (Celtis occidentalis)
- Blue Ash (Fraxinus quadrangulata)
5 species of trees/shrubs that have a distribution generally limited to high-lime, clay-rich substrates developed in the thick glacial till of western Ohio:
- Sugar Maple (Acer saccharum)
- Beech (Fagus grandifolia)
- Shagbark Hickory (Carya Ovata)
- White Ash (Quercus alba)
- Hawthorn (Crataegus mollis)
5 species of trees/shrubs that have a distribution generally limited to sandstone hill of eastern Ohio:
- Chestnut Oak (Quercus montana)
- Sourwood (Oxydendrum arboreum)
- Mountain Laurel (Kalmia latifolia)
- Huckleberry-blueberry (Vaccinium ssp.)
- Hemlock (Tsuga canadensis)
Distribution of picky substrate trees: The Sweet Buckeye, the Hemlock, and Rhododendron
When comparing the Sweet Buckeye (Aesculus flava) and the Hemlock (Tsuga canadensis) it is noticed that they are present in the southeastern part of Ohio. The reasons for restrictions in distribution of the sweet buckeye are not known, but may have something to do with the problem of repopulation, by these plants, of the clayey, high-lime glacial till in the short time since the ice left Ohio. It is unclear why the sweet buckeye does not extend as far north as the glacial boundary in eastern Ohio. It is theorized that this is because of the climate controlling the distribution. Similarly, the eastern hemlock occurs in the sandstone ridges and valleys of the unglaciated regions of Eastern Ohio. In the reading it is noted that the Hemlock does occur in the northern parts of the unglaciated land. It prefers cool, moist, and deep cut valleys which contain some till. Even though the till is thicker in the north of the glacial boundary which is less acidic, the cool moist north-facing valleys provide adequate substrate for the hemlock.
Lastly, the Rhododendron is found south of the glacial boundary since it is used to the Appalachian highlands and when the environment was changed by the glaciers north of the boundary it didn’t persist. This can be explained by the valleys of the Teays river as a means of distribution. The glaciers caused the Teays river drainage to become blocked, but the plants had already migrated.
Battelle Darby (Wetland/Prairie, Limestone plants, and a special assignment)!
We first began our hike by exploring the wetlands of Darby Creek. First, we looked at a sedge that is called the Tall flatsedge it’s scientific name is Cyperus eragrostis. Now you might be wondering what the difference between sedges and grasses are so I am here to help you. The stems of sedges are generally solid and triangular a good way to remember this is by the mnemonic, “sedges have edges”). The stems of grasses on the other hand are hollow and rather round or flat with either swollen nodes or joints along their stem. The grass that we looked at was named Kentucky bluegrass also known as Poa pratensis. Both of these are monocots. .What is a monocot you might ask? A monocot is a grass and grass-like flowering plant that typically contain one embryonic leaf or cotyledon. The leaves on a monocot are generally parallel-veined. Generally, their floral organs are arranged in multiples of three. Just so you know a dicot has 2 cotyledons, broad leaves, and their floral organs are arranged in multiples of 4 or 5.
The tall flatsedge often grows in moist grasslands as you may have guessed! Sometimes it escapes from native areas and invade other biological growth species. It can be kind of problematic because of the fact that it likes to escape and it can infest rice fields and decrease yield. Generally cold temperatures help control the weed’s spread. Did you know that the Cyperus eragrostis is edible and it was used as a papermaking material?! Me neither! (https://candide.com/GB/plants/9483cf0a-e5b6-4b4b-84a6-3005bef60495)
Kentucky bluegrass is a very common grass that is planted in cool and humid parts of the United States. When looking at this plant you may not notice much blue. The name does not refer to the color of the grass stalks rather it is due to the purple-blue flowers that are seen if the grass is allowed to bloom. The Kentucky bluegrass can withstand high traffic areas due to it’s tough blades and deep roots. Next time you’re outside I challenge you to look for some Kentucky bluegrass. (https://www.pennington.com/all-products/grass-seed/resources/all-you-need-to-know-about-kentucky-bluegrass)
Right here we have a beautiful picture of the common hackberry also known as Celtis occidentalis. While reading about the common hackberry Peterson’s field guide let me know the common hackberry has leaves that are alternate, simple, around 2.5 inches long, with unequal bases and a sharp tapering tip. The common hackberry is known for having warty bark and it loves a limey substrate similar to the other three plants we are going to learn about soon.
The blue ash is known for being high off the ground with vigorous twigs often square in cross section. The twigs are hairless and they have long lines leading from leaf scars. The leaves of the blue ash are opposite, pinnately compound, and 8 inches to 12 inches long when fully grown. The inner bark of the blue ash also yields a blue dye!
The fragrant sumac is a low bush or rambling shrub with 3-parted large-toothed leaves that have a pleasant odor when crushed. Their twigs are brown and the bark is relatively smooth. The fruits of the fragrant sumac are small, hairy, red, ball-shaped, clustered, and bloom around May-June. Wild turkeys like the fragrant sumac for its fruit!
Lastly, of the lime lovers we have the eastern redbud. The eastern redbud has alternate, simple, broad, and heart shaped leaves. When this tree blossomed it has a reddish hue. The flowers are sometimes eaten in salads! The eastern redbud is a member of the pea family!
The Lifespan of Plants
Before learning about our last topic from the Battelle Darby trip, I think it is important we do a short review of the lifespan of plants. Annual plants germinate, bloom, set seed and die all in one year. Biennial plants have a life cycle of two years, so they terminate and grow one year, bloom and die the following. Lastly everything that lasts longer than two years is perennial. This means it grows and flowers for many years.
When at Battelle Darby I noticed two different plants that had different life spans. I began with the American Columbo also known as Fraser’s caroliniensis and then looked at the glass mermaid-weed scientifically known as Floerkea proserpinacoides.
Here we have the American columbo. This is a herbaceous plant that is a monocarpic perennial. This plant has a rosette of 3-30 basal leaves for 5-15 years that finally bolts a flowering plant that becomes anywhere from 3-8 feet tall for a single season. It then unfortunately dies, but consider yourself lucky if you get to see the American columbo bloom! (https://www.illinoiswildflowers.info/savanna/plants/am_columbo.html)
What a fun name. The false mermaid and then unfortunately followed by weed. The false mermaid is a herbaceous weed that is an annual. It is native to the finger lake region. The plant spreads by reseeding itself and it has so few seeds it’s chances of surviving are relatively high. Compare this to the amount of acorns that fall off a tree… the chances of survival are relatively small. The delicate foliage is very attractive! (https://www.illinoiswildflowers.info/woodland/plants/fs_mermaid.htm)