1988 Yellowstone Park Fires:
Surprising Discoveries Several Years Later




“The Yellowstone blaze [of 1988] created thousands of ‘edges,’ --- zones between living forest and fire-cleared land --- that most biologists agree are among the most biologically diverse . . . places in nature.

“Roy Renkin vaulted a charred log, stooped, and pointed to a tiny green aspen shoot struggling up through ash-blackened earth. Renkin, 32, the son of a Pittsburgh steelworker, has made a historic discovery about aspen trees that wouldn’t have been possible if roughly a third of the nation’s oldest national park hadn’t burned to charcoal in 1988.”

Comments:
What Renkin found is that the aspen stands began growing from seedlings instead of sprouting from existing root-systems, even though those rizomes (the growth clusters or nodes from which new stands of aspen arise) were unharmed by the fire, being protected underground. Normally, aspen stands spread from these rizome systems much more than from seedlings. But the seeds are apparently not just fire-resistant, but are prompted to germinate after intense heat has passed.

Does this process also increase genetic diversity, due to increase in sexual reproduction (the use of seedlings)? The seeds that sprout after fires of course would presumably be those already in ground and buried from earlier seasons, germinated now by the huge heat of the fire. They are thus a ‘backup system’ for reproducing if the root systems are damaged by the fire [?].

It would be natural to assume that protected underground root systems, rather than exposed surface seedlings, would be the system upon which a species like aspen would rely after a natural catastrophe like a forest fire. But in this case, it seems as if the seedlings can get the stands springing up again in the quickest time, exploiting the new soil nutrients that are laid down because of the fire. (Maybe?) And it may also be that the seedlings yield more quickly to flowering tree-sprouts and thus to sexual reproduction and genetic recombination---surely an asset in a population under stress. So the seedlings are not just a “backup” system of reproduction (for the root nodules are the primary reproductive resource in normal seasons) but a leap forward, a feint and a dodge and a rapid multiplication and recombination of a population’s genetic resources in the face of danger....

Renkin’s discovery was possible only after a huge fire of the type that swept Yellowstone in 1988---a fire that scientists think is of a magnitude that appears only once every 100 to 300 years.

[Above quotations from an article by Dan Baum and Margaret L. Knox, Philadelphia Inquirer E1, E4, 5-22-90, an article on the Yellowstone fires and scientific discoveries coming in their wake. Other speculations are my own.]

And urban brownfield revival?




graphics above and below:

Mel Chin,

Revival Field

Netherlands

(temporary installation)

from A.R. Ammons’s long poem Garbage (Norton, 1993), p. 84:

communicative motions making sounds, much mutual
glistening in a breezy grove of spring aspen speech

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