Ridge is a broad, gently sloping plateau in the Cascade Range of western
at bottom). It lies along the boundary of the older, steeply dissected
West Cascades and the younger peaks of the High Cascades (map, at
right). Elevations range from 1220 to 1375 m (4000 to 4500 ft) and
slopes are gentle (<5%), facing primarily southwest. Climate is
maritime, with warm dry summers and cool, wet winters. Most precipitation
falls during winter, with >1000 cm of snowfall. Snowpacks can exceed
2 m and persist into late May.
encroachment of conifers into meadows has been dramatic. (See photo-sequence,
at right.) For much of the 20th century, the study area
supported a mix of forest and meadow, but many open areas have since
been filled by trees. See more research on the patterns and consequences
invasion at Bunchgrass Ridge.
The plateau supports a mosaic of dry meadows, areas of recent encroachment
(<90 yr), and older forests (>100-200 yr) of lodgepole
pine (Pinus contorta) and grand fir (Abies grandis).
Forest understory species are typical of rich, mesic sites (e.g.,
Smilacina stellata, Achlys triphylla, Galium
oreganum, and Anemone oregana). Meadows
are dominated by graminoids (e.g., Festuca idahoensis, Bromus
carinatus, and Carex pensylvanica) and a diversity of
species list (PDF).
the Pleistocene, glaciers carved valleys to the north and south
of Bunchgrass Ridge and scoured the summit, leaving the current
raised plateau. Lateral moraines lie to the south of the ridge,
and pothole lakes (Kuitan and Robinson) to the northeast.
Soils have developed under grassland vegetation for centuries. They
are deep (>170 cm), fine to very-fine-sandy loams derived from
andesitic basalt and deposits of tephra with variable amounts of
glacially derived cobbles, stones, and boulders. Soil
history. Although there is no direct evidence of
recent fire, fire-return intervals are long (>100 yr) at this
elevation in the Cascades. Native Americans used fire to maintain
open habitats throughout the Northwest, but stumps within the experimental
plots do not show evidence of fire, and archeological surveys have
not produced artifacts indicative of human use of the meadow prior
to Euro-American settlement.
by sheep is likely to have occurred during the early part of the
20th century, when grazing in the Cascades was widespread.
However, the local history of grazing at Bunchgrass Ridge is not
recorded in Forest Service archives.
encroachment at Bunchgrass Ridge
the 1946 photo, trees that dominate the forest-meadow
mosaic established in the 1800s. Clearcuts adjacent
to the study area are evident in the 2000 photo.