Dear HCN,
I would like to applaud
High Country News for publishing and Frederic H. Wagner for writing
the May 30, 1994, article about “natural regulation” policy in
Yellowstone National Park. I have worked in and around the park off
and on from 1969 to 1985 and continue to visit it periodically. As
a soil mapper, I observe and make judgments about disturbances to
the natural landscape because they relate to soil
development.
In the northern range of Yellowstone
Park, I saw unusual vegetation patterns compared to surrounding
areas of the region. Aspen stands in the park were nearly all old
age, contained no young or medium age classes and few if any
sprouts. This is not uncommon for a species normally associated
with early stages of succession. Don Despain, the Park Service
botanist, explained the absence of young trees in the early 1970s
as due to the absence of natural disturbance from fire, which would
rejuvenate the aspen. But it seemed odd that many areas outside the
park had young stands often on the margins of conifer forests. It
was also impossible to find an aspen tree in the park which had
white bark below the browse line. The elk and possibly bison would
chew the bark leaving black scars on the trunk. An aspen blown over
by the wind would lose all leaves and bark within
days.
After the 1988 fires aspen trees sprouted
profusely and it appeared that fire was an essential ingredient to
restore the aspen stands. In 1992 and 1993 I went through the park
to find that the sprouts were not getting more than a few feet
tall. That is as much growth as some aspen make in one year and it
had been four years since the fire. I assume the sprouts had been
browsed by the elk and deer and possibly bison. I wonder how
natural this is.
Robert
Ottersberg
La Grande,
Oregon
This article appeared in the print edition of the magazine with the headline Twisted science in Yellowstone.
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