Part 2 focused on how wildfire-requiring prairies & savannas moved way, way to the east & northeast & even south in multiple periods of drier, warmer weather over the past 10,000 years. The most significant period was the Hypsithermal between 5000-8000 years ago. In between, it was a constant pendulum swing between forests, savannas, barrens, brushy open woods & prairies. Certainly drought is less prevalent in our region than it has been over the past 200 years, tree rings, diaries & temperature records show that.
Prairie outliers existed even in southwestern Indiana. I took these pics of some small remnants of prairie & barrens on formerly Clark's, Round, Willow Lick, Steele Prairies of northern Daviess County, Indiana back around 2001. These were all close to home. I was doing study work on the plants of this area & the ties to the larger prairies in Illinois, Iowa, Missouri & in our area of northwestern & north-central Indiana.
In fact, early land surveys point the exact location of these prairies & some botanical collecting was done in the area by acclaimed Indiana botanists Deam & Freisner in the early 1900s.
NOTE: WELL, I THOUGHT I HAD THESE PICTURES DOWNLOADED....GUESS THEY DID NOT DOWNLOAD....WILL TRY TOMORROW.
Climate may have been a big force, but wildfires were the big forces & they helped maintained these more open environments in cooler, wetter times that favored forests.
So, when the first Europeans arrived here, what had & was maintaining the open prairies, savannas, brush, barrens of our area? The clear factor was wildfire. These ecosystems were dependent upon it & Native American were the driving force of maintaining these open environments when forest should have been encroaching on them more than ever.
There are many mentions of Native American-induced wildfires in local county histories & diaries showing that they burnt the prairies & savannas in an effort to encourage grazers like bison. They would use fire to even trap bison for hunting by lightning a circle of flames to surround herds. In such a flammable landscape with grass incredibly dense & up to 9' in height in the heart of Tippecanoe & Benton to Clinton County prairies, once a fire got going with such a flat landscape it would burn for days in the early spring & late fall with the sun shrouded in smoke. So, already flammable, it is possible that lightning may have sparked a few fires from time to time, but Native Americans were integrated into the ecosystem. They had been for thousands & thousands of years. In fact Native American called Benton County "Maskotia" or "land of fire".
A wildfire could start on the flat till plains of central Illinois & literally keep going with a strong southwest wind for days & burn multiple counties. It might even last weeks, burning much of Benton to Tippecanoe counties. Rain, a natural firebreak or a change in wind direction could deter it.
So, in summary of this entry, grasslands/savannas began with a rain shadow & a cooler & drier climate, evolved to depend on massive grazing mammals of the North American Serengeti & some occasional fires, then saw often massive expansions far, far to the east with drying climate & more fires, which was helped by Native Americans. Native Americans became ingrained into the ecosystem by perpetuating prairie & savanna maintainance by burning (& occasional lightning strikes at the right time helped).
These fires were usually brought forth in areas that saw a period of dryness suitable for flammable grasses to burn during the year with few fire breaks. Thus, wetter areas to our east & southeast had much more forest than our area when the first Europeans arrived.
By Frederick Remington:
John Curry's "The Prairie Fire":
George Catlin's "Prairie Meadows Burning""