Bald Fire site in the Experimental Network for Assisted Migration and Establishment Silviculture (ENAMES)
The Bald Fire site, part of the Experimental Network for Assisted Migration and Establishment Silviculture (ENAMES) study, has been established in the Eldorado National Forest to test assisted population migration of ponderosa pine, as well as the effect of planting density and configuration on seedling survival and growth. The site burned during the 2014 Bald Fire and was planted in 2025.
Landowner: U.S. Forest Service
Location: Lassen National Forest, Hat Creek Ranger District
Nearest town: Hat Creek, CA
Planted species: Primarily ponderosa pine (Pinus ponderosa) with a mix of Jeffrey pine (Pinus jeffreyi) in some treatments.
Site history: The site, originally an east-side marginal pine forest, burned in the 2015 Bald Fire. Study sites are in mixed ponderosa pine/Jeffrey pine stands, with scattered black oaks and western juniper.
Site characteristics: The site is at a mean elevation of 4850 ft, split into 4 disjunct blocks, on gently sloping terrain facing a variety of aspects. The soils are a mix of fine-loamy, mixed, mesic Ultic Argixerolls and loamy-skeletal, mixed, frigid Ultic Haploxeralfs. The mean annual temperature is 48 °F (coldest month 33 °F, warmest month 67 °F) and mean annual precipitation is 495 mm (45 mm as snow).
Planting date: 2025
Contact person:
Jessica Wright, Research Geneticist, Pacific Southwest Research Station
Christopher Looney, Research Forester, Pacific Southwest Research Station
Pre-planting site conditions at the Bald Fire site. Photo by Christopher Looney.
The planting crew on planting day at the Bald Fire site. Photo by Kara Sanghera.
Site preparation: The site was salvage harvested in 2022 and sprayed with herbicide in 2023.
Pre-planting site conditions: Sites were logged in the years prior to planting. Large trees were removed and small trees and branchwood were chipped on-site. Sites had been unsuccessfully planted several times during the droughty late 2010s without vegetation control. Occasional planted ponderosa pines survived from these previous plantings and were not targeted for removal prior to study site establishment. One experimental block had scattered sprouting black oaks, but plots were otherwise repositioned where possible to avoid non-target herbicide effects on these hardwoods. Damage from cattle trampling and browse has contributed to regeneration failures.
Assisted migration treatments: The team used the Climate-Adapted Seed Tool to choose four planted seed sources (see table below).
Ponderosa pine seed sources
Climate period
| Seed origin | Seed source elevation (ft) | Mean cold month temperature (°C) | Summer heat-moisture index |
Historical/local (1961-1990) | CA Seed Zone 732 (Lassen/Modoc National Forest) | 5000-5500 | -1.48 | 188.98 |
Early-century (2011-2040) | CA Seed Zone 322 (Klamath National Forest) | 2000-2500 | 1.61 | 274.20 |
Mid-century (2041-2070) | CA Seed Zone 742 (Shasta National Forest) | 3000-3500 | 0.54 | 239.87 |
Late-century (2017-2100) | CA Seed Zone 302 (Six Rivers/ Klamath National Forest) | 500-1000 | 5.48 | 185.84 |
Jeffrey pine seed sources
Climate period
| Seed origin | Seed source elevation (ft) | Mean cold month temperature (°C) | Summer heat-moisture index |
Historical/local (1961-1990) | CA Seed Zone 732 (Lassen/Modoc National Forest) | 5000-5500 | -1.48 | 188.98 |
Early-century (2011-2040) | CA Seed Zone 322 (Klamath National Forest) | 3000-3500 | 1.39 | 266.23 |
Mid-century (2041-2070) | CA Seed Zone 742 (Shasta National Forest) | 5500-6000 | 4.91 | 204.08 |
Late-century (2017-2100) | CA Seed Zone 302 (Six Rivers/ Klamath National Forest) | 3500-4000 | 7.23 | 346.22 |
Silvicultural treatments: 4 treatments: stock type (bareroot vs container) and species mix (pure ponderosa vs 50:50 mix of ponderosa and Jeffrey pines for bark beetle resistance). All seedlings received vexar shelters to protect against ungulate browsing.
Planting density: Contract crews planted 250 trees per acre with a target surviving density of 125 trees per acre. Higher planted density acknowledges harsh conditions and prior planting failures.
Seedling stocktype: Containerized and bare root.
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.
Year 1 results
In the graphs below, bars with same letter (for example, a) indicate no significant difference among seed sources/climate scenarios. Different letters (such as a vs b) indicate a significant difference based on latest measurements.
Figure 1. Seedling survival for the different seed sources 1 year after planting at the Bald Fire site.
Figure 2. Seedling diameter by seed source 1 year after planting at the Bald Fire site.
Figure 3. Seedling growth by seed source 1 year after planting at the Bald Fire site.
Silviculture results: Bare root seedlings had significantly higher diameter and significantly lower height and survival. The ponderosa pine/Jeffrey pine mix plots had significantly lower height and higher diameter than the ponderosa pine plots.
Silviculture-climate interactions: The local/historical seed source had significantly lower height for the bare root, but not container seedlings. The local/historical seed source also had lower survival in mixed species bare root plots only.