Falls Creek site in the Experimental Network for Assisted Migration and Establishment Silviculture (ENAMES)

Falls Creek 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: Bureau of Land Management (BLM).

Nearest town: Silverton, OR.

Species: Douglas-fir (Pseudotsuga menziesii).

Site history: The site, originally a predominantly Douglas-fir stand, underwent a thinning in 2012 and a regeneration harvest in 2022.

Site characteristics: The site is at an elevation of 2,500 ft and faces south-southwest, with a moderate slope of ~10°. The soils are deep, well-drained gravelly loams formed in colluvium from andesite, breccias, tuffs, and volcanic ash, and silty loams formed in loess and glacial till from igneous and metamorphic bedrock. The mean annual temperature is 46 °F (coldest month: 36 °F; warmest month: 59 °F) and mean annual precipitation is 2177 mm (154 mm of which is snow).

Planting date: Spring 2024.

Contact person:
Kenneth Ruzicka, Silviculture Lead, Bureau of Land Management, Cascades Resource Area.
Robert Slesak, Research Forester, USDA Forest Service, Pacific Northwest Research Station.

Pre-planting site conditions at the Falls Creek site. Photo by Tessa Franklin.

Management objectives and other considerations: The Falls Creek site is located in the “harvest land base” land use allocation for the BLM, which is managed to for timber production. This experiment will help the BLM develop the best silvicultural tools to control competition and species mixtures to ensure timber production under a changing climate.

Site preparation: None.

Pre-planting site conditions: The site has extensive woody debris throughout, including large, scattered slash piles. Clumps of large live trees are scattered throughout the site as well. Experimental plots were placed to avoid these clumps and debris as much as possible, but they were unavoidable in some areas. Understory regeneration was very minimal, with no visible natural conifer regeneration.
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 Falls Creek site. Map by Laura Gonzalez Mantecon.

Silvicultural treatments: Herbicide application with four treatment variations (two different radiuses of treatment, one application vs. two applications.)

Planting density: Operational contract crews will plant 250 trees per ac.

Seedling stock type: Styro 515 containerized stock.

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.