Crouched over a metal screen like a gold rush prospector and peering through its grid at the forest floor, Cindi Persichetty calls out what she sees through each square-inch opening: "Line four: moss, moss, litter, seedling, seedling, seedling." Another Idaho State University graduate student, Mike O'Hara, sits on a log recording the findings on a clipboard.
The charred remains of a lodgepole
pine loom above them, groaning in the morning breeze that rises off
the Madison River in Yellowstone National Park. The forest floor is
carpeted with thousands of bright green seedlings, each less than a
Directed by researchers Jay Anderson
of Idaho State University and William Romme of Fort Lewis College
in Durango, Colo., the monitoring seeks to answer the question of
how fire affects the regeneration of lodgepole
"Their thinking is that if the fire gets
into the crown of the trees it will kill a lot more of the seeds
and so you'd have less seedling density in those areas,"
Five years of monitoring by
Anderson, Romme and other scientists has documented an amazing
recovery from the 1988 fires that consumed nearly 1 million of the
2.2 million acres of Yellowstone Park.
in most burned areas has recovered quickly. Water flows increased
in many streams without causing erosion as severe as some feared.
Mammal populations have remained steady or are
Lodgepole pine, which grows in vast
stands throughout the western United States, has evolved to
regenerate after a fire. Its cones are usually "serotinous,"
opening and dispersing their seeds when exposed to heat. But
Yellowstone's storm of fires was so big and so hot that many
wondered how well the lodgepole would
"Even under conditions as extreme as in
the summer of 1988, widespread holocaustic fires rarely consume
entire landscapes," Anderson says.
that lodgepole seedlings are common - up to 400 per acre - in the
moderate burns. But lodgepole regeneration is also occurring in the
most severe burns, and the density of seedlings in all but four of
the transects is more than sufficient to replace the stands of
"The Yellowstone fires are not
likely to create vast meadows where forests stood in 1988,"
Anderson and Romme said in their report to the First Biennial
Scientific Conference on the Greater Yellowstone Ecosystem last
year. "We suspect that the majority of the park's burned areas will
be characterized by extensive stands of evenly aged forests, much
like the pattern in evidence after the fires of the early 1800s."
The big impact on the Yellowstone ecosystem from
the 1988 fire may turn out to be an upsurge of aspen. Anderson and
Romme reported finding aspen seedlings in all their study sites,
even where no aspen stands grew before the
Roy Rankin, a National Park Service
biologist, has reported aspen seedling densities ranging from 1 to
1,000 per square meter in burn areas throughout
According to another Park Service
biologist, Don Despain, author of Yellowstone Vegetation, most
aspen reproduction in Yellowstone is by way of suckers, which are
genetic clones that grow from the parent tree's lateral root
"In Yellowstone, it is not unreasonable
to assume that many of the clones present today started as the
glaciers retreated, 12,000 to 14,000 years ago," he explains. "If
this is the case, the aspen we see now have lived through a lot of
climatic and environmental changes. It is conceivable that the
aspen clones being browsed by deer and elk today were once fed upon
by mammoths, horses and camels."
rarely germinate in Yellowstone because the seedlings are too small
to compete with other vegetation and are very sensitive to even
moderately dry conditions. They require plenty of sun and moisture
to thrive. Despain and Rankin theorize that the 1988 fires produced
the exact conditions aspen seeds needed: elimination of most of the
competing vegetation, creation of large open spaces with plenty of
sunshine, and leftover fire ash which helped increase the
water-holding capacity of the soil.
agency biologists have begun monitoring 15 of the new aspen
seedling sites as well as 10 sites with aspen suckers to compare
success rates. And they are watching how aspen seedlings compete
The seedlings that prevail will
likely dominate the next generation of Yellowstone
free-lances from Shoshone, Idaho.
information, contact John Varley, chief of research, Yellowstone
National Park, WY 82190-0168 (307/344-2203) and the Greater
Yellowstone Coalition, P.O. Box 1874, Bozeman, MT 59771