Interagency Clearinghouse of Ecological Information

Photo Tour of Treatments

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.

Light Thin

The light thin treatment is similar to 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.

Aerial Photos by Sonja Weber
Stand Photos by Gabriel Tucker