The Greater Yellowstone Ecosystem - Mountains and Plains: The Ecology of Wyoming Landscapes - page 265

Marshall, thomas Hobbs, and David cooper concluded
that a lack of willow and aspen food sources in the early
twentieth century led to local extirpation of beaver along
some small streams, where beaver dams formerly main-
tained high water tables. Subsequent down-cutting in the
absence of beaver caused a lowering of the water table,
resulting in habitats that were too dry for willows, and
now, they reasoned, the willows in such places do not
grow well even when fenced to exclude elk browsing . 100
As another example of cascading ecological effects,
wolf reintroduction has led to a decline in the number
of coyotes in Jackson Hole, which in turn has resulted
in greater survival of pronghorn fawns . 101 the value of
large wildlands for understanding ecological processes
is again eminently clear.

underscored the importance of conservation efforts on
private lands in and surrounding the GYe. For example,
ecologists Andrew Hansen and Jay Rotella found that
hotspots for bird diversity and abundance tend to occur
not in the high-elevation wilderness areas, but on low-
elevation private lands that are increasingly vulnerable
to degradation. 102 in fact, this seems to be true for the
region as a whole.
Given the natural complexity of this ecosystem—
coupled with issues of boundary effects, land use
changes, invasive species, and climate change—it is
difficult to know what management actions should be
adopted, and to what degree natural processes are suf-
ficient for maintaining the GYe . 103 Managers are still
learning about the effects of their decisions, and often
the lessons are unexpected. Historian Paul Schullery
wrote, “one of the most important contributions science
has made to management dialogues in the past 30 years
is to elevate the admission of uncertainty as a credible
management stance.” 104 Despite difficulties and con-
troversies, the Yellowstone country remains a national
treasure, indeed a global treasure. With the return of
the gray wolf, the GYe again has all of the species and
more or less the same ecological processes that existed
when YnP was established in 1872. equally important,
away from the roads, the GYe elicits a powerful sense of
wildness and beauty.

on some days, the GYe is tranquil with elk, bison,
moose, and pronghorn at rest in expansive meadows.
the rivers are clean, and the thermal features are fasci-
nating curiosities for resting hikers on a warm summer
day. However, such tranquility belies the long winters
that plants and animals must endure, the forest fires
that periodically burn across the landscape, and the
molten rock that exists close to the earth's surface. the
challenges of protecting such unique places, over such
a large area, are formidable. Much research has focused
on the GYe's public lands, but recent analyses have