Hillockburn Springs site in the Experimental Network for Assisted Migration and Establishment Silviculture (ENAMES)
The Hillockburn Springs site, part of the Experimental Network for Assisted Migration and Establishment Silviculture (ENAMES) study, has been established on Bureau of Land Management land in NW Oregon to test assisted population migration of ponderosa pine using four seed sources that match historical and predicted future climates at the site, as well as the effects of herbicide application on seedling establishment and growth. The site burned during the 2020 Riverside Fire and will be planted in the spring of 2024.
Hillockburn Springs 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: Dodge, OR.
Species: Douglas-fir (Pseudotsuga menziesii).
Site history: The site was originally a mixed clearcut/thinned 50-year-old Douglas-fir stand before burning in the 2014 36 Pit Fire. After the fire, BLM salvage harvested and planted each site with Douglas-fir and western redcedar at 200 trees per ac. The site burned again during the 2020 Riverside Fire.
Site characteristics: The site is at an elevation of 1,700 ft and faces north-northeast, with a slope of 15–25°. The mean annual temperature is 49 °F (coldest month: 37 °F; warmest month: 62 °F) and mean annual precipitation is 1772 mm (80 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 Hillockburn Springs site. Photo by Broderick DeAngelis.
Management objectives and other considerations: The Hillockburn Springs 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: Mechanical woody debris and shrub removal will be completed before planting.
Pre-planting site conditions: The site is largely clear of overstory, with some standing dead and live trees in certain areas. After mechanical woody debris removal, the ground should be fairly clear.
Assisted migration treatments: The team used the Seedlot Selection Tool to choose four planted seed sources (see table below.)
Climate period
| Seed origin | Seed source elevation (ft) | Mean cold month temperature (°C) | Summer heat-moisture index |
Historical/local (1961-1990) | BLM–Molalla area | 600–2,400 | 2.78 | 54.4 |
Early-century (2011-2040) | BLM–McKenzie area | 800–2,700 | 3.50 | 74.4 |
Mid-century (2041-2070) | BLM–Swisshome/ Mapleton area | 800–2,500 | 4.32 | 71.3 |
Late-century (2017-2100) | BLM–Coquille 16 area | <1,600 | 6.36 | 80.6 |
Seed source locations matching historical and predicted future climates for the Hillockburn Springs 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.
Forestry technician James Dollins delimiting the corner of an experimental plot at the Hillockburn Springs site. Photo by Broderick DeAngelis.
Figure 1. Seedling survival for the different seed sources one year post-planting at the Hillockburn Springs site.
Figure 2. Seedling diameter by seed source one year post-planting at the Hillockburn Springs site.
Figure 3. Seedling growth by seed source one year post-planting at the Hillockburn Springs site.
Map
-
https://research.fs.usda.gov/sites/default/files/2023-10/pnw-hillockburnspringslayout.pdfFile Type: pdf
File Size: 5.40MB
Project
-
Project
https://research.fs.usda.gov/pnw/projects/enames