The four treatments compared in
this study are: Control (uncut, avg. 261 tpa), Light thin (thinned to 105
tpa), Heavy thin (55 tpa), and Light Thin with Gaps (same as light thin
but with additional clear-cut .5 acre gaps over 20% of the treatment).
The gap (delineated in red) and heavy thin (green) treatments are easily
distinguished in the aerial photograph of the Christy Flats Site below.
The control is outlined in blue and the light thin in yellow. Stand-level
photos of each treatment accompanied by three aerial photos are displayed
below the Christy Flats treatments photo.
The Young Stand Study targets stands 35-50 years old. As you can see,
there are many young stands in the Cougar Reservoir area (top right).
The lower row photos were taken at Christy Flats in Oakridge and Lookout
Ridge in the McKenzie Bridge Ranger District.
Gap Thin treatments
The stand-level photo was taken from the perimeter of the gap facing
its center. Aerial photos are of McKenzie Bridge, Sidewalk Creek,
and Christy Flats (in clockwise order from the top). These treatments
mimic the mortality patterns of small fires and root-rot outbreaks. Eventually
the gaps will be replanted to speed the establishment of this future cohort.
Heavy Thin
The heavy thin treatment opens the canopy dramatically, perhaps allowing
more rapid diameter growth as well as understory development. Both of these
characteristics can be advantageous for wildlife habitat. The upper
right and lower left photographs were taken above the Blue River Sites
near Cougar reservoir, bottom right is of the McKenzie Bridge site.
Light Thin
The light thin treatment is similar a standard commercial thin.
In our stands about half the stems were removed leaving around 110 trees
per acre (tpa). This treatment was included in the study to yield
quantitative data on how most typically managed forests are behaving, among
other things. The top right photo is of Christy Flats, lower right:
Blue River (just to the west of Cougar Res.), lower left: McKenzie Bridge.