I Took Real Photographs Of Pleistocene Landscapes

[MarkGelbart]

I was there. I jumped in a time machine and saw the Pleistocene and even took pictures of the landscapes.

Ok, actually I visited a grassy bald on Roan Mountain, North Carolina which is supposed to be a relic landscape of the Pleistocene. Peter Weigle, a scientist at (I believe without doublechecking my facts) Wake Forest, theorizes the balds formed during the Ice Age when the climate killed the trees, leaving only grass. Mammoths, bison, musk-oxen, horses, and llamas grazed the upland pastures and kept trees from regrowing. After their extinction, bison and elk still maintained the grassy balds, then the European colonists grazed their livestock there. Once mountain farming became uneconomical, trees started growing on these Appalachian balds, and now they're endangered. While I was there, a crew was assembled and ready to weed whack the Canadian blackberry that's encroaching on the bald. The forest service also uses goats and Watusi cattle to maintain the balds.

There are disjunct populations of plants with more northern ranges here. Mountain oat grass is common in Canada but doesn't occur at lower elevations surrounding the bald. There are also plants such as Greenland sandwort and many others that only occur far to the north of North Carolina. During the ice age, these plants had a continuous population probably as far south as the piedmont region of Georgia.

I think the forest service should re-introduce elk and bison to help maintain the balds.

In any case the photos I took above look just like much the way the landscapes of the North American Ice Age looked. We were up in the clouds and the temperature dropped from 61 degrees F. to 59 degrees during mid-morning. Much nicer than the 95 degrees I returned to in Augusta, Georgia.

[Auspex]

I think the forest service should re-introduce elk and bison to help maintain the balds.

Grasslands persist in the face of encroaching woody vegetation through the natural mechanism of fire. Controlled burning is the proper prescription.

[ashcraft]

Three things control grasslands

1)Lack of moisture

2)Action of large animals (or nowadays bush-hogs)

3)Fire

Of the three, moisture is the most important, a tree requires huge amounts of water, in the order of millions of gallons weekly, without it, it won't survive. Here in S.E. Missouri, we have huge "sand dunes" which are remnants of the Ohio River. These hills are only about 20' higher then the surrounding "swamp bottoms", but they drain so quickly that very few trees can survive long enough to get roots down to the relatively shallow water table. Lewis and Clark actually killed Prairie Chickens off of them early in their voyage. Bison, elk, and other herbivores kept the post oak from sprouting (one of the few that can survive), and the Native Americans also burned the areas nearly yearly to promote grass growth (or to kill chiggers, depending on who you talk to)

Brent Ashcraft

[Auspex]

^^

All true, but if the soil/climate will not support woody vegetation, then their encroachment is not an issue. Discontinuous grazing by herds of large animals that are free to roam is part of the grassland ecosystem, but overgrazing my non-migratory (or confined) animals is as destructive of a grasslands as a tractor with a six-bottom plow.

[MarkGelbart]

Grasslands persist in the face of encroaching woody vegetation through the natural mechanism of fire. Controlled burning is the proper prescription.

Scientists believe Appalachian balds are a little different. They don't think it was fire that maintained the balds.

According to this paper--"Grassy Balds of the Great Smoky Mountains: Their History and Flora in Relation to Potential Management," by Mary Lindsay and Susan Braton in the Journal of Environmental Management V. 3 (5) Sept. 1979 (and available online as a pdf), the National Park Service experimented with fire and compared it to grazing by goats, sheep, and cattle. Though fire maintained the grassy openings, the mix of plants species wasn't the same as exists on natural grassy balds.

On Roan mountain they use goats and cattle, but the grazing is controlled.

[Tr-J-K]

Reintroduce probescidians!

[MarkGelbart]

Three things control grasslands

1)Lack of moisture

2)Action of large animals (or nowadays bush-hogs)

3)Fire

Of the three, moisture is the most important, a tree requires huge amounts of water, in the order of millions of gallons weekly, without it, it won't survive. Here in S.E. Missouri, we have huge "sand dunes" which are remnants of the Ohio River. These hills are only about 20' higher then the surrounding "swamp bottoms", but they drain so quickly that very few trees can survive long enough to get roots down to the relatively shallow water table. Lewis and Clark actually killed Prairie Chickens off of them early in their voyage. Bison, elk, and other herbivores kept the post oak from sprouting (one of the few that can survive), and the Native Americans also burned the areas nearly yearly to promote grass growth (or to kill chiggers, depending on who you talk to)

Brent Ashcraft

We have eolian sand dunes in Georgia too but most today are covered in vegetation--mostly scrub oaks and pines. I've studied a number of papers on the formation of eolian sand dunes and Carolina bays. During dry climate cycles of the Ice Age, rivers were less meandering and instead were braided around sand bars and islands. The number of available water holes shrunk in number and the megafauna congregated around the river, further denuding the landscape. Southwesterly and some westerly winds rolled these sand dunes across the land, so that today they're all on the northeast side of rivers. Most (but not all) scientists think it was wind and water action that created Carolina bays as well. In the south some sand dunes have buried Carolina bays.

Here's a diagram I drew of the formation of eolian sand dunes. (And I hope I can get a professional illustrator for my book who can make a better one.)