Volume IV No. 3 - September, 1931
Snow Pressure Bend
By Clyde E. Gilbert, Ranger-Naturalist
The trees inside the rim of Crater Lake and on the steep slopes of
the surrounding peaks show a distinct bend near the base. The bend
might be accounted for by some as due to soil creep. "Soil creep" is
the gradual downward slipping of the soil on the steep hillsides. This
is usually caused by alternate freezing and thawing of the soil aided by
the water table in the early spring. Since the soil on the slopes is
quite shallow and many of the tree roots are anchored in solid rock, it
is very improbable that soil creep is responsible for the bend. Also in
the case of soil creep the base would have moved down slope and the tops
tilted upward. If a resulting bend occurred it would be in the opposite
direction to that found in Nature.
It appears more probable that snow pressure on the trees for six
months or more of the year forces the trees out of the line of normal
growth and causes a distinct crook that is called "snow bend". The tree
is most affected while it is very small. Some times it is pressed flat
on the ground beneath huge drifts of snow for several months. During
the growing season the sun draws the tree back into an upright position
but before it can completely straighten the snow falls and again presses
the tree out of line. Every year the growing tree, aided by the sun,
gains a bit in the battle, but even the larger trees show a distinct
"snow bend" that is never outgrown.
Assisting Nature
By E. U. Blanchfield, Ranger Naturalist
Visitors to the park this summer are extremely interested in the
planting activity on the Rim from the entrance of the Rim Road to the
Lodge. The rim walk winds through this planted area among native shrubs
and flowers.
As the soil on the Rim is pumice and not favorable to plants, rich
soil has been transplanted from bogs and stream banks and spread over
the pumice.
At the head of the Lake Trail is an excellent planting layout of
mountain ash, black twinberry, red twinberry, pink spirea, and native
grass which forms an intersection of the lake and rim walks.. In the
shaded locations under the mountain hemlocks are planted western
bleeding hearts, alpine phlox and mountain valerian, The false green
hellebore, Coville's aster, fireweed and Crater Lake currant are all
prominent at this season on the Rim edge. The Crater Lake currant is
being used as a creeping plant to beautify the new Sinnott Memorial
Building. In between the rocks of the building are planted a matted
beard tongue, the lace fern, seedum, softening the lines of the
architecture. These plants have been obtained from the rock crevices on
the side of Garfield Peak.
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