13. How Much of Ohio Was Prairie Before Europeans Took Over? When Ohio became a state in
1803, at least 2% was open prairie. Some more accurate, recent investigations indicate that about 4%
was actual prairie. As the textbooks say, most of Ohio was originally forest, along with many larger
wooded wetlands, marshes, and bogs. But significant regions of Ohio had large landscape prairies. At
the greatest extent just before settlement, Ohio had about 1700 square miles of prairie (1,088,000 acres)
of prairie. The major prairie areas are shown on the Prairie Regions of Ohio map below.
14. If Ohio Prairies Were Destroyed Before 1900, How Can We Be Sure Where They Were? Good
question. Fortunately we know about our destroyed prairies from several accurate sources. The first is
the written accounts of early settlers. Because the prairies were so different from the Eastern homeland
forest areas from which settlers originated, there are many settler accounts of local Ohio prairies from
the early 19th century. These historic writings tell about local prairies, noting the animals encountered
there, and the hardships (fires, lack of roads, difficult plowing conditions, other harsh wilderness
conditions) that prairie settlers faced.
The second strong line of evidence about the size and location of Ohio’s prairies comes from the first
official land survey records. Before land could be sold in Ohio, it had to be properly surveyed and the
survey results filed in a local courthouse or land office. Because Ohio lands were to be purchased
primarily by new settlers from the East who were looking for cheap but productive farmland, the early
surveyors kept accurate records of the trees and plants they encountered in their surveys. They were
careful to mark the borders of a prairie on their surveys because Easterners originally thought that land
that couldn’t grow trees (as on a prairie) had to be infertile and therefore probably wouldn’t make a good
farm site. Later, it was discovered that the treeless prairies were extremely fertile.
Consequently, the old official land records in all parts of Ohio tell the location and sizes of Ohio’s original
prairies.
Lastly, remnants of these once-great prairies still survive in ditches, along railroad rights-of-way, in old
cemetery corners, and other scattered areas still unshaded by trees. Most Ohio prairie plants were never
able to scatter and grow beyond their prairie origins, so today, when we notice a patch of prairie
coneflower (Ratibida pinnata) or prairie dock (Silphium terebinthinaceum) growing along a rural lane or
an abandoned railroad, we can be pretty sure that these are rare survivors of a prairie that once grew in
profusion near the site. By putting dots on a map wherever these prairie plant remnants are seen, the
resulting map looks just like the prairie maps made from both settlers’ accounts and like maps from
surveyors’ records. Although Ohio’s great prairie landscapes are gone forever, we know for sure where
they once were. It’s an exciting story.
15. So, Where Were Those Great Ohio Prairies? The records indicate that Ohio’s largest prairies were
located in eight major areas (although small prairies existed in all parts of Ohio.) They are shown on the
map below. The specific prairie borders here are only generalizations. The shown prairies
represent only closely-approximate locations and sizes. Numerous original smaller prairies
throughout all regions of the state are not shown here. These weren't Ohio's only prairies–just
the largest.
• The Oak Openings. In northwest Ohio was the famous Oak Openings prairies and savannas. This
region of dry sand ridges and low wet swales was a mixture of dry sand prairies interspersed with flat
wet prairies and dry oak savannas.
• The Wood County Black Swamp Wet Prairie. Also in northwest Ohio, in Wood County, was a curious
large, flat wet prairie surrounded by the great Black Swamp, a giant elm-ash lake plain swamp forest.
The only remnants of this unique prairie now reside in Wood County’s deep ditches that were originally
dug to drain the swamp and prairie.
• The Castalia - Sandusky Bay Prairie. Further to the east, in Erie and Sandusky Counties, was the
Castalia Prairie, a wet fen prairie. Because portions had blocky chunks of tuffa rock, some of the
Castalia Prairie was seldom or ineffectively plowed. Consequently, one of Ohio’s finest, intact prairie
remnants is the 40-60 acre Castalia Prairie on Northwest Road at the Resthaven Wildlife Area near the
village of Castalia. The modern Castalia Prairie remnant retains a number of rare and endangered
plants, moths, and other species. The Castalia Prairie, maintained by the Ohio Division of Wildlife at the
Resthaven Wildlife Area, is a state natural treasure.
• The Firelands Prairie. Nearby, between Bellevue on the southwest, extending northeast to Huron on
Lake Erie, was the great Firelands Prairie. The Firelands Prairie was one of the easternmost large
prairies in all of North America.
• The Sandusky Plains. To the south, in north central Ohio, was a significant region of prairies, known
as the Sandusky Plains. This large area straddles the headwaters of the north-flowing Sandusky and
south-flowing Scioto and Olentangy Rivers.
• The Darby Plains. The sixth great Ohio prairie area was the Darby Plains in the counties west of
Columbus. Prairies and savannas stretched across several counties that are, today, an extremely fertile
agricultural region. Extensive prairie restorations by Columbus Metroparks are returning several areas to
large native prairies. Two state nature preserves, the Bigelow and Smith Cemetery Prairies, and a few
railroad rights of way give a glimpse of the botanical beauty of this great prairie area.
• Adams County (Lexington Plains) Prairies. In the south, near the Ohio River, in hilly Adams County,
there are numerous prairie patches and remnants. The Adams County prairies are noted for their
abundance of rare and uncommon prairie species. This interesting region is actually a northern
extension of the Kentucky bluegrass ecological region south of the Ohio River.
• Mad River Prairie Fens. In southwest Ohio, in the greater Dayton area, were a good number of small
valley-bottom fen prairies. Along local rivers and creeks there were a number of larger local prairie
landscapes.
• Other Ohio Prairies. Other prairies, usually small ones, were scattered across the rest of Ohio. In fact,
prairie openings in the Eastern forest extended all the way to the Atlantic Ocean. Ohio is the eastern
edge of the large landscape prairies of the Midwest, but small prairie areas were found far to the east.
16. How Can We Know What Plants Were On
Original Ohio Prairies? Another good question.
We have discovered where Ohio’s prairies were.
But do we know what they were, what plant
species lived there? Yes, we do, by these means.
Neither the early surveyors nor the settlers were
botanists. Therefore, the early records merely
mention “prairy” or “grasses” or “plains.” The
prairie plants were a mystery to those from the
forested East. The historical records of Ohio’s
early landscapes aren’t much help in determining
what prairie grasses and forbs actually grew in the
state. But other records do give us a pretty
accurate rendering of Ohio’s natural prairie botany.
By the end of the 19th century, and well into the 20th, Ohio colleges and universities had botany
departments with capable professors and students. These individuals made field collections of local
plants and deposited these mounted, dry specimens in college herbaria, repositories of identified,
pressed plants. From these many historical records we can determine almost all of the species of plants
that once grew in Ohio’s local prairies.
For example, in the 1890s a Sandusky High School science teacher, Edwin Lincoln Moseley, frequently
took students on all-day field trips to distant parts of Erie County in the northern part of the state. He and
his students collected hundreds of plant specimens from forests, marshes, and local prairies, noting the
species and locations. E.L. Moseley then compiled this great list of local plants and had it published.
There were still many local patches of unplowed prairie, and Moseley’s lists of plants provides an
unparalleled picture of the field botany of the great Firelands Prairie once prominent in Erie and Huron
Counties. Botanists in other regions of Ohio likewise collected local prairie plant specimens that still
survive in historic herbaria.
Lastly, rare prairie plant survivors are still being discovered in ditches, along railroads, open woodlot
edges, and other isolated spots. Consequently, we have a very accurate listing of what plants lived on
Ohio’s prairies. The discovery of these plants, both as inhabitants of the original prairies (from the
collected plant records) and also as live remnant populations, has been (and continues to be) a great
scientific investigation.
Therefore, we now know both where Ohio’s prairies were, and what plants lived on them.
17. What Kinds of Prairie Existed in Ohio? Another good question. A prairie is not just a prairie. There
are several distinct types of prairie in North America, and Ohio had examples of most of them.
First, the kind of prairie Ohio didn’t have. The great shortgrass prairies of the high plains and regions
next to the Rocky Mountains were absent from Ohio. These great grasslands supported the enormous
herds of bison (“buffalo”) and the Plains Indians. Rainfall is restricted on these prairies, with just enough
(<1 ft, <30 cm) to grow short native grasses. These short grasses are very nutritious and can support
large roaming herds of bison. Ohio, however, has too much rainfall for these dry-region grasses. Our
prairie grasses were much taller. Ohio didn’t have the kinds of prairies found in Montana, Wyoming, and
other Western States. It was too moist for these prairie plants.
Ohio’s prairies were tallgrass prairies, prairies that were dominated by two or three species of tall native
grasses. The most common of these was the king of the prairie, big bluestem grass. Big bluestem in
Ohio grows to 6 - 8 ft or more. Indiangrass is another such grass, followed by switchgrass and prairie
cordgrass.
So, in general, most of Ohio’s prairies were tallgrass prairies with very tall mature grasses. But prairie
ecologists divide the tallgrass prairie into a number of specific kinds, depending on the amount of
moisture in the local soil.
Two areas may have identical amounts of rainfall, but very different kinds of plants will grow in each. The
amount of moisture in soil greatly affects the kinds of plants that will grow on a site. For example, one
site may have been flat and wet with heavy clay soil. Nearby could be a rolling site with a sandy soil.
Both sites get exactly the same rainfall but will have very different prairie plant communities. Prairies are
divided by available soil moisture, in the following categories.
Wet (or Hydric) Prairie. A wet prairie experiences lengthy periods of wet or saturated soil. Wet prairies
are usually on low or flat sites often with heavy clay soils. Wet prairie plants grow well in these harsh
conditions. Wet prairies are often very fertile and always have large amounts of vegetation (biomass).
But they tend to have reduced kinds of plants (reduced biodiversity).
Wet prairies once covered large areas of Ohio, especially on the flat Lake Plain in the northern counties
adjacent to Lake Erie.
Mesic Prairie. Mesic (“MEE- zic") prairie grows on soils that are not excessively dry nor excessively
moist.
Soil moisture is ideally even. Mesic prairie soils are frequently loams, with even amounts of sand, silt,
and clay. Mesic prairies have a large number of plant species.
Dry (or Xeric) Prairie. Xeric ("ZERR - ic") prairie grows in sand or other dry soils, often on hillsides or
other well-drained sites. Because moisture is less available, xeric prairie plants are usually smaller and
more widely spaced than those on hydric and mesic sites. But xeric prairies frequently have rare or
uncommon plant and animal species. The famous sand prairies of the Oak Openings region west of
Toledo are quintessential xeric prairies in Ohio.
Then there are two intermediate prairies, sharing some of the qualities and plants of the two adjacent
prairie types.
Wet-Mesic Prairie. Wet-mesic prairie is intermediate between wet and mesic prairie. A few species of
plant prefer wet-mesic prairies.
Dry-Mesic Prairie. Dry-mesic prairie is less dry than a xeric prairie, but not as moist as a mesic one.
Again, a few species of plants grow particularly well on these prairies.
Prairies, then, can be classified by their soil moisture, in this sequence (wet to dry):
Wet Prairie – soils very wet for lengthy periods. Wet (or Hydric) Prairie – soils very wet.
Wet-Mesic Prairie – soils somewhat wet.
Mesic Prairie – soils neither too wet nor too dry.
Dry-Mesic Prairie – soils somewhat dry.
Dry (or Xeric) Prairie – soils very dry.
But this arrangement, based only on soil moisture, fails to identify a few local prairie types that are
controlled by other local factors.
One important such local prairie is a fen. The word fen comes from Great Britain and Europe where
there are landscapes dominated by plants that grow only in wet areas of alkaline or calcareous soils. A
number of Ohio wet prairies grow in these soils, the most famous, perhaps, is the Castalia Prairie at the
Resthaven Wildlife Area near Castalia, Ohio. Groundwater here rises up through pure limestone and
marl (calcium carbonate), making the soil very alkaline (>7pH). A number of very rare prairie species
require this wet prairie, fen condition. Many local prairies in southwest Ohio are fen prairies.
A few Ohio xeric prairies are so-called “sand barrens,” areas with infertile sand and a reduced number of
prairie plant species. Most prairies, even xeric ones, have very fertile soils. Sand barren prairies tend to
have infertile soils and support reduced numbers (but very interesting) prairie plant species.
Lastly, in steep or hilly parts of Ohio many local prairies are known as “goat prairies.” Goat prairies are
apparently called that because only a goat could remain standing in these often rocky, sloped sites.
Many of the interesting prairies of Adams County in Ohio’s southern region are goat prairies. Goat
prairies may be the only prairies that could survive without frequent fires because they are often on
almost vertical, harsh, cliff-side sites where shading trees have a tough time growing to full size. Of
course, both sand and goat prairies tend to be dry or dry-mesic prairies.
Ohio has a wonderful diversity of prairie types.
18. Is a Savanna a Type of Prairie? Well, yes it is, and no it isn’t. True prairies have few or no trees.
Unshaded, direct sunlight dominates the prairie landscape.
But some prairie areas are curious mixtures of open prairie and scattered forest trees. These are known
as prairie savannas. A savanna is generally defined as a prairie area with scattered trees (usually oaks)
that allow unshaded sunlight to fall between the widely spaced trees. Beneath each tree, however, the
prairie can be quite shaded, creating a varying sequence of shaded to unshaded habitats.
Savannas are dominated by scattered oaks, usually of the following species. The classic savanna oak
(on wet-mesic, mesic, and dry-mesic sites) is the famous bur oak, Quercus macrocarpa. Also on similar
sites can be the great white oak, Quercus alba. Black oaks, Quercus velutina, are common savanna
oaks on dry and dry-mesic soils. On wetter sites the swamp white oak, Quercus bicolor, can sometimes
be found in a savanna setting.
Prairie savannas are important and exceptionally rare environments, some of the rarest in the world. The
Oak Openings region west of Toledo has some of the world’s finest prairie savanna habitats, with a large
number of rare or endangered plants and animals. Prairie savannas should be specially treasured.
Prairie savannas are special places where ecological forces are in centuries-long conflict. As noted at
the beginning, a prairie that is not frequently burned soon becomes overgrown and crowded out by
shrubs and trees. But in a few areas, usually on lighter, drier soils, fires did not occur with annual
frequency. Fires were frequent enough to retard shading by shrubs and brush, but not frequent enough
to stop the growth of scattered oak trees. Oaks (and one or two species of hickories) are well-adapted to
fire. Most young sapling trees are killed by a prairie fire. And so are oak seedlings if the fires occur
almost annually (as they did when Native Americans lived in Ohio).
But if prairie fires in dry and dry-mesic areas are slightly less frequent, with occasional fire-free intervals
of, perhaps, 10-20 years, then seedling oaks can grow tall enough that the flames of a prairie fire can’t
kill all of the limbs. Oak trees, especially those that grow in savannas, have thick, insulating bark, and
withstand much hotter fires than other tree species. Oaks are the best-able trees to withstand fires, and
therefore in sandy dry prairie areas, where the prairie vegetation isn’t as dense as on wetter sites (has
less fuel), oaks can begin to invade the prairie and survive with less frequent fires.
After oaks reach 25 ft or more, the heat of a surrounding prairie fire only kills off the lower branches. The
tree survives. A savanna is created.
If the fires cease altogether, however, new young oaks will start growing densely. In a few short years,
the former prairie or open savanna will become a shaded oak forest. This interplay of fire and shade on
the prairie savanna makes this rare environment unique and ecologically entrancing. Savannas are
special interfaces between the open, sunlit prairie and the fully shaded, tree-canopied forest. Savannas
share characteristics of both the forest and the prairie, but in interesting ways unique to this special
environment.
19. Weren’t Most Ohio Prairie Fires Set Naturally By Lightning, Not Humans? A lot of people think
so. They are certain that most natural landscape fires in prehistoric Ohio were touched off by lightning,
not by humans. They believe this simply because they don’t think Native Americans had any reason to
set wild landscapes on fire, and because they still believe that frequent wildland fire is ultimately
destructive.
This may descend from the European view of America’s “noble savages,” a perception that Native
Americans were never contaminated with the destructive ideas of European life. It is commonly believed
that Native Americans always lived in perfect natural harmony with their environment, and in modern
western eyes, the frequent setting of wildland fires doesn’t fit with this idealistic (but unsubstantiated)
view.
Frankly, there is no evidence whatsoever that Native Americans refrained from setting frequent
landscape fires in presettlement Ohio. On the contrary, there is overwhelming evidence that
natives set fire to virtually all landscapes that would support fire. Only areas that were wet were
spared.
What is the evidence of frequent, human-set landscape fires? First, we turn again to the earliest written
records of Ohio landscapes. Virtually every record of Ohio’s early forests (early 19th century and before)
tell of our great forests. But the descriptions of these don’t match with modern forests – and not because
modern forests have been logged, either.
Early Ohio forest descriptions tell, of course, of the great size of the trees. These great trees could not be
harvested without iron tools, unavailable to early Native Americans. Naturally, trees were of great size.
But tree size is not an indication of the presence or absence of frequent fire. The absence of fire is
indicated by the presence of brush and small trees between the large, mature trees. In virtually every
modern Ohio forest (where fires have been absent for decades), the ground layer is covered by low
shrubs, brush, vines, and sapling trees. One can often see only a few hundred feet into a modern forest
because of the thick, low brush.
This modern condition was seldom, if ever, described in early Ohio forest accounts. Early Ohio forests
are frequently described as absent of low brush. The forest floors were said to be open, park-like and
easily traversed. This could be arranged only by the frequent, deliberate burning of the leaves on the
forest floor.
But couldn’t lightning have set these forest-floor leaf fires? It could, but only rarely. If lightning-caused
forest leaf fires were common, then today’s forests would look like early Ohio forests. They don’t
because neither humans nor lightning frequently ignite modern Ohio forests. Without fire, forest-floor
brush continues to choke the modern forest. Native Americans abhorred this brush because it made
walking difficult. Like it or not, Native Americans frequently burned Ohio’s landscapes, even the
forested ones.
But the greatest fires, of course, were the prairie fires. In forests, annual fall or spring leaf fires had low
flames that moved slowly across the forest floor, killing brush and small trees, leaving the large trees
unharmed. But prairie fires were very hot, quick, and fast-moving. What is the evidence that humans set
these areas on fire?
The best evidence is that there were large prairie landscapes in Ohio. The undeniable truth is that any
unburned (or un-mowed) Ohio prairie will in a decade or so become brush-shaded and lost. Fires
are essential factors in the maintenance of prairies in high-moisture areas such as Ohio. If there was a
natural prairie, there was frequent fire. Otherwise, the prairie became shaded and was lost to brush and
forest.
But still, why didn’t natural lightning keep Ohio’s prairies sufficiently burned? That’s the crucial question
to ask anyone who contends that Ohio prairie fires were a result of lightning, not humans. The question
is, “What is the evidence that natural lightning was the major cause of Ohio prairie fires?” No such
evidence has ever been presented. Still, many conveniently attribute Ohio prairie fires to lightning,
mostly because they have no reason to believe that Native Americans would have done this. But, they
did.
Again, what is the evidence? It is this. All Ohio fire departments are required to report to the state fire
marshal the cause, size, location, type, and other information on every fire responded to in Ohio.
Consequently, an examination of the state database on reported wildland fires will reveal their locations
and dates. This has been done (the analyzed data are too lengthy to include here), and the modern
lightning-set wildland fire data show that today there are never enough lightning-caused wildfires to
maintain Ohio’s prairies.
For example, most of Ohio’s lightning occurs during the “green” months, in late spring, summer, and
early fall, when prairies are green and actively growing. Anyone who has tried to burn a prairie during
this period knows that even setting such a fire is difficult, and getting it to spread further into the green
prairie is slow and uncertain. Green grass doesn’t burn well, even if it’s 6 ft tall. Real prairie fires, ones
that kill brush and seedling trees, occur either in late fall, after the vegetation is somewhat dry, or in
March or April when prairie vegetation has almost completely dried and is very flammable.
The fire marshal lightning fire data simply show that very little ground-touching lightning occurs in Ohio
when prairies could be easily set afire. There is no reason to believe that lightning occurs less frequently
today than it did several hundred years ago.
Lastly, unlike in the Rocky Mountains where “dry” lightning is well known, Ohio lightning is commonly
accompanied by drenching rain. Even if Ohio prairies were occasionally touched by fire from the sky, the
concomitant rain would have extinguished any fire spread.
Then, there is a very significant, but little-recognized final reason Native Americans set prairies (and
forest floors) on fire each year — hygiene. Unburned natural areas harbor dense populations of ticks and
chiggers, which can both cause discomfort and transmit diseases. Native Americans understood that
burned areas had reduced populations of human ectoparasites; life in those areas was more pleasant,
more healthful.
In summary, the only way prairies could have existed for 5000 years or so in Ohio was for them to
have been frequently set afire by human beings. Without those fires, Ohio’s great forests would
have soon over-shaded the sun-dependant prairies. But human-set fires retarded forest
expansion into the prairie, and also provided deer-attracting areas that could be easily “hunted”
by the game-confining and game-herding fires themselves. Dry lightning, in dry environments,
when prairies can be burned in late fall and early spring, simply doesn’t occur often enough to
maintain large prairie landscapes in the Buckeye State. Ohio prairies were therefore
anthropogenic, human-caused. Ohio prairies are a valuable, direct natural legacy of Ohio's great
Native Americans.
Native Americans didn't just live on Ohio's prairies, they created and maintained
them.
Frequently Asked Questions
About Ohio Prairies P. 2
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