Demonstration of Ecosystem Management Options Study
 |
DEMO Home |
 |
About Us |
 |
History |
|
Experimental Design |
|
Treatment Implementation |
|
Study Areas |
|
Contact Us |
|
Photo Gallery |
|
Publications & Presentations |
|
Research |
 |
Resource Management and Productivity Program |
|
Pacific Northwest Research Station |
|
USFS Research & Development |
|
Evaluate
Our Service Your comments and suggestions are very important to our service improvement. |
|
Pacific Northwest Research Station |
|
|
|
|
DEMO Home > About Us > Experimental Design
About Us
Experimental Design
The DEMO study consists of a randomized complete block design, consisting of six, 13-ha structural retention treatments (see descriptions and photos below), including a control, replicated at each of six blocks (geographic locations). Treatment units are square or slightly rectangular in shape. Within each unit, sampling is integrated around a permenent grid system (8 x 8 or 7 x 9 points at 40-m spacing). For a detailed treatment of the DEMO experimental design and harvest prescriptions see:
Aubry, K.; Amaranthus, M.; Halpern, C.; White, J.; Woodard, B.; Peterson, C.; Legoudakis, C.; Horton, A. 1999. Evaluating the effects of varying levels and patterns of green-tree retention: experimental design of the DEMO study. Northwest Science. 73(Special Issue): 12-26.
Descriptions of Treatments
|
1. 100-percent retention: a 13-ha control that provides a baseline for assessing the effects of harvest treatments on ecosystem composition, structure, and function. |
|
|
|
2. 75-percent aggregated retention: Three circular, 1-ha patches are harvested in a triangular array, removing 25 percent of the original stand area. The pattern and distances between "gaps" are consistent among experimental blocks. |
|
|
|
3. 40-percent dispersed retention: a proportion of the dominant and co-dominant trees are retained in a relatively even distribution throughout the treatment unit. The total basal area retained is equivalent to that of the corresponding aggregated retention treatment (40 percent aggregated retention). |
|
|
|
4. 40-percent aggregated retention: five undisturbed, 1-ha circular aggregates are retained at fixed distances from each other; all merchantable trees in the surrounding area are cut and removed. |
|
|
|
5. 15-percent dispersed retention: a proportion of the dominant and co-dominant trees are retained in a relatively even distribution throughout the treatment unit. The total basal area retained is equivalent to that of the corresponding aggregated retention treatment (15 percent aggregated retention). |
|
|
|
6. 15-percent aggregated retention: two undisturbed, 1-ha circular aggregates are retained at fixed distances from each other; all merchantable trees in the surrounding area are cut and removed. |
|
US Forest Service - Pacific Northwest Research Station, Demonstration
of Ecosystem Management Options
Last Modified: Thursday,27March2008 at12:34:02EDT