Detroit sites in the Experimental Network for Assisted Migration and Establishment Silviculture (ENAMES)

Detroit site 3D map showing experimental plots color-coded by the climate scenario each seed source is adapted to. Map by Laura Gonzalez Mantecon.

Land manager: USDA Forest Service.

Location: Willamette National Forest, Detroit Ranger District.

Nearest town: Detroit, OR.

Species: Douglas-fir (Pseudotsuga menziesii).

Site characteristics: The sites are directly adjacent to the Detroit Ranger Station, at an elevation of 1,800 ft, and face southwest, with a moderate slope of 6 to 15°.  The soils are deep, somewhat well drained gravelly cobbly loam formed from colluvium and slide deposits derived from igneous rock mixed with volcanic ash. The mean annual temperature is 49 °F (coldest month: 35 °F, warmest month: 64 °F) and mean annual precipitation is 2,088 mm (138 mm of which is snow).

Site history: These sites were part of second growth predominantly Douglas-fir stand before it burned in the 2020 Beachie Creek Fire. Due to their proximity to the Detroit Ranger Station and campground, they were probably intensively managed.

Planting date: Spring 2023.

Contact person:
Scott Kolpak, Regional Geneticist, USDA Forest Service, Pacific Southwest Region (formerly Southwest Oregon Area Geneticist).

Mark Leis, Forester, Willamette National Forest, Detroit Ranger District.

Robert Slesak, Research Forester, USDA Forest Service, Pacific Northwest Research Station.

Site conditions at the Detroit site in the summer of 2023. The foreground shows the salvaged site, with the non-salvaged site behind it to the left and Detroit Lake in the background. Photo by Laura Gonzalez Mantecon.

Management objectives and other considerations: TBA.

Site preparation: One of the sites was salvage harvested, while the other had no site preparation.

Pre-planting site conditions: At the time of planting, the salvaged site had no remaining overstory, a few stumps, minor woody debris and little vegetation, with a ground cover of mostly trailing blackberry (Rubus ursinus) and lady fern (Athyrium felix-femina.) The non-salvaged site had a significant amount of both standing and down dead trees and woody debris, with a similar trailing blackberry and lady fern ground cover. Both sites showed some small Douglas-fir natural regeneration.

Experimental design: A randomized complete block with four replications per treatment applied to 0.5-acre plots.

Assisted migration treatments: The team used the Seedlot Selection Tool to choose four planted seed sources (see table below.)

Seed source locations matching historical and predicted future climates for the Detroit site. Map by Laura Gonzalez Mantecon.

Silvicultural treatments: None.

Planting density: Operational contract crews planted 200 trees per ac.

Seedling stock type: Containerized.

Monitoring: The site will be monitored to track and compare seedling survival among seed sources and silvicultural treatments. Measurements are planned for 1, 5, 10, and 15 years after planting.

The site may also serve as a demonstration plot for managers to visit and visually compare seed source performance.

A recently planted seedling at the Detroit site. Photo by Laura Gonzalez Mantecon.

Some areas of the Detroit site are covered by dense shrubs and woody debris, making it hard to see the planted seedlings (marked with small orange flags). Photo by Laura Gonzalez Mantecon.