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Pacific Northwest Research Station
Large-Scale Silvicultural Experiments In Western Oregon and Washington
Olympic Habitat Development Study
Initial Installation Years: 1997-2006
Primary Objectives: Test management alternatives for their ability to accelerate development of characteristics associated with older stands. Test if accelerated development of the structures that are missing in the younger stands will increase the function of the ecosystem as habitat for forest-floor dwelling terrestrial amphibians and small mammals.
Pre-treatment Conditions: 35- to 62-year-old, even-aged stands.
Locations: Bait (47.3900°N, 123.9100°W), Clavicle (48.0400°N, 124.2100°W), Eats (47.5700°N, 124.0400°W), Fresca (48.0500°N, 124.2900°W), North Fork Fulton (47.6500°N, 123.0000°W), Rail (48.0600°N, 124.0700°W), Snow White (47.9300°N, 122.9700°W), and Triton (47.6200°N, 123.0100°W).
Initial Treatments: 4 thinning x planting x woody debris treatments and 1 unthinned control each replicated 1 time at 8 locations.
No Overstory Removal (Control)
Control (1a). Not thinned. Not planted. No woody debris or other initial treatments.
Light Overstory Removal
Moderate Overstory Removal
Variable Density Thinning, not planted, CWD clumped, slash dispersed (3a). Thinned 75% of stand to 75% of pretreatment basal area. Cut 15% of stand to create small gaps. Left 10% of stand as uncut patches ("skips"). Not planted. CWD clumped and slash dispersed. No other initial treatments.
Variable Density Thinning, not planted, CWD dispersed, slash dispersed (3b). Identical to OHDS treatment 3a, but with CWD dispersed and slash dispersed.
Variable Density Thinning, planted, CWD clumped, slash clumped (3c). Identical to OHDS treatment 3a, but native understory species planted or seeded in existing or newly created openings and with CWD clumped and slash clumped.
Variable Density Thinning, not planted, CWD removed, slash dispersed (3d). Identical to OHDS treatment 3a, but with CWD removed and slash dispersed.
Heavy Overstory Removal
Complete Overstory Removal (Clearcut)
Response Variables: Over-, mid-, and understory vegetation; mosses; large, arboreal, and small mammals; bats; arthropods; amphibians; mollusks; snags; woody debris; fungi; microclimate; wood production; operational factors; roads; forest floor.
Study Plan: Harrington, C.A.; Carey, A.B. 1997. The Olympic Habitat Development Study conceptual study plan. On file with: C. Harrington, U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, Olympia Forestry Sciences Laboratory, 3625 93rd Avenue SW, Olympia, WA 98512.
(last accessed 2006-12-06)
US Forest Service - Pacific Northwest Research Station