Maintaining Mountain Meadows
You may not notice any movement now, but forests at
this meadow's edge are on the march. Research indicates
that on the North Rim, mixed conifer and aspen forests
encroach upon some open, grassy areas at a rate of one
foot (30 cm) each year.
Meadows remain open for many reasons, including
grazing by deer and digging by rodents. Melted snow
and rain create conditions too wet for tree seedlings to
germinate. Seedlings that survive may not tolerate
exposure to sun. Soil toxins also may affect woody
plants, but not herbs and grasses that provide forage for
small mammals. Ponderosa pine seedlings cannot
compete with well-established grasses.
Although tree encroachment is not fully understood, fire
is also an important factor. Before the Outlet Fire burned
this area in spring of 2000, the forest was infacign the
better-drained soils along the edge of this meadow.
The fire may have slowed the advance of the forest.
Predators such as mountain lions,
coyotes (left), fox, and many raptor
species often hunt their prey where
meadows and forest converge
A single aspen tree once grew in the
exposed conditions of this meadow.
Quaking aspens regenerate quickly
after fires such as the spring 2000
Outlet File.
