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A WHIFF OF THE PAST
Steward T. A. Pickett;
Institute of Environmental Studies,
P.O. Box AB, Route 44A
Millbrook, NY 12545-0129;
STAPickett@aol.com
NOTE: The following document is posted to provide a look at
new ideas and developing components of the LUHNA project. No reproduction
or other use of the materials posted here should be undertaken without
consent of, and discussion with, the author. Please note e-mail
address, above.
* * * * * * *
Paul Martin, a distinguished paleoecologist, pulled a mysterious, dusty
chunk from a plastic bag as he started talking about the past environments of
the American southwest. I was intrigued because rarely is "show-and-tell" a
part of a professional workshop. This was something different, and promised
to add interest to this meeting. Perhaps I wouldn't have to fight fatigue
when the lights were turned off and the slides splashed on the screen.
My fascination turned to apprehension when Prof. Martin continued. The
dusty chunk he had pulled from the big baggie was the mummified feces of the
extinct Shasta ground sloth. He held the flaky, olive mass easily in his two
hands, and told us he would pass it around. He wanted us to "breathe
moistly" on it, and then inhale the aroma. He demonstrated for us,
theatrically exhaling and taking a deep sniff. Although Paul apparently
suffered no negative effects, the look of dread on the face of the person
sitting next to him, Ron Pulliam, the Director of the National Biological
Service, mirrored my own apprehension.
But still there was something fascinating about the fossil. It was
produced by an animal that was long extinct. According to radiocarbon
dating, the dung ball was at least 10,000 years old! I had seen photographs
of skeletal remains of the ground sloth, and drawings of how paleontologists
reconstructed the extinct animal. But Shasta ground sloths, which would have
been about as large as an adult black bear, had been extinct for thousands
and thousands of years. At least, as a scientist, I was about to experience
something quite extraordinary. I could be stoic for that.
The specimen was passed around the circle, and people began timidly to
follow Paul Martin's instructions for experiencing it. I was relieved when
the lights were turned off so that he could show slides of his research sites
in the arid mountains of the Southwest, including the dry cave where the
dried sloth feces came from. At least in the dark, people wouldn't be able
to see me take my turn at "huff and snuff."
When the dry lump finally got to me, I was greatly relieved to find that it
bore no resemblance at all to a dried cow pie, which had been my initial
fear. It was light, fibrous and seemed perfectly harmless. Emboldened by
its innocuous character, and hidden from the prying eyes of the other
workshop participants by the dim light of the slide show, I did as Paul had
told us: I exhaled moistly on the wad, and took a deep, lung-filling breath
through my nose.
The fragrant aroma I inhaled transported me, in my mind, to the savanna of
Africa, where I had been in fact less than 18 months before. The herbaceous
scent of the coprolite of an extinct North American herbivore was the same
perfume as I had smelled rising from the productive savanna woodlands in
contemporary Africa. Living browsers and herbivores fertilized the South
African savanna with droppings that made the cool air at sunset redolent with
the sweet smell of the foliage they had eaten and drawn nourishment from.
And from the shared aroma a vision emerged: a large North American
herbivore, emerging from its cave to find nearby a mixture of trees and
shrubs that grow now only in the moister environments some 3000 feet higher
in elevation. Now, the cave opens onto the Mojave Desert, but this aroma of
moist foliage recalled a very different environment, which Paul said would
have supported single-leaf ash and juniper trees, shad scale shrubs, some
cactus, globe mallow and even some aquatic plants. The herbaceous odor made
that ancient, long-gone environment a reality for me.
Environmental change is something ecologists are used to, at least
intellectually. We read technical papers about the ecological past, and
often see the diagrams and the reconstructions of past environments in
scientific texts and journals. But this whiff of the desiccated dung from
what is now the Mojave Desert, of an extinct animal that would have lived in
a much moister woodland environment, made the past real in a visceral way.
Each part of North America has an ecological past that is deep and radically
different from the environment at that site today. Some of the changes from
the past result from natural climate change and the migration of species,
while some result from changes made by humans. The deep past helps
ecologists understand the way that ecosystems work and species behave and are
distributed today. And I had just had an 10,000 year old whiff of it.
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Last Updated: Tuesday, 15-Aug-2000 08:26:50 MDT
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