Happy Camp sites in the Experimental Network for Assisted Migration and Establishment Silviculture (ENAMES)
The Happy Camp sites, part of the Experimental Network for Assisted Migration and Establishment Silviculture (ENAMES) study, has been established in the Klamath National Forest to test assisted population migration of Douglas-fir and ponderosa pine. The sites burned during the 2020 Slater Fire and was planted in 2024.
Pre-planting site conditions at the Happy Camp site. Photo by Christopher Looney.
Landowner: U.S. Forest Service
Location: Klamath National Forest, Happy Camp Ranger District
Nearest town: Happy Camp, CA
Planted species: Douglas-fir (Pseudotsuga menziesii), ponderosa pine (Pinus ponderosa)
Site history: The sites are in an area administered by the Forest Service, Pacific Southwest Region (Region 5) genetics program for tree planting and research purposes for about 50 years. Specifically, the sites sit in the former location of sugar pine blister rust resistance trials conducted by Region 5. It is a fenced area that burned with high severity, leaving virtually no trees. The sites burned with high severity during the 2020 Slater Fire.
Site characteristics: The sites are at an elevation of 2500 ft on generally flat terrain. The soils are Clayey, oxidic, mesic Xeric Haplohumults. The mean annual temperature is 53 °F (coldest month 38 °F, warmest month 71 °F) and mean annual precipitation is 1679 mm (65 mm as snow).
Planting date: 2024
Contact person:
Marie McLaughlin, Seed Procurement Manager, Pacific Southwest Region
Jessica Wright, Research Geneticist, Pacific Southwest Research Station
Christopher Looney, Research Forester, Pacific Southwest Research Station
Management objectives and other considerations: The sites are in an area long used for genetic research. The assisted migration trial is the only current management objective.
The sites have a climate that may support rare California tree species, so, in addition to the assisted migration trials, the team is planting Santa Lucia fir (Abies bracteata), threatened and endangered cypress species (Hesperocyparis spp.), and a Sierra Nevada population of foxtail pine (Pinus balfouriana ssp. austrina) as an ex-situ conservation site and a possible seed source for future conservation efforts focused on these rare species.
Site preparation: The sites are part of a very well-maintained facility and burned with high severity so site preparation is not necessary.
Pre-planting site conditions: TBA
Assisted migration treatments: The team used the Climate-Adapted Seed Tool to choose four planted seed sources (see tables below).
Douglas-fir 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 301 (Klamath National Forest) | 2000-2500 | 3.73 | 146.4 |
Early-century (2011-2040) | CA Seed Zone 523 (Lassen National Forest) | 2500-3000 | 2.75 | 210.6 |
Mid-century (2041-2070) | CA Seed Zone 525 (Tahoe National Forest) | 2500-3000 | 5.55 | 239.2 |
Late-century (2017-2100) | CA Seed Zone 524 (Plumas/Lassen National Forests) | 1500-2000 | 7.03 | 273.4 |
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 301 (Klamath National Forest) | 2000-2500 | 3.73 | 146.4 |
Early-century (2011-2040) | CA Seed Zone 311 (Klamath National Forest) | 1500-2000 | 4.21 | 223.1 |
Mid-century (2041-2070) | CA Seed Zone 525 (Tahoe National Forest) | 2500-3000 | 5.55 | 239.2 |
Late-century (2017-2100) | CA Seed Zone 521 (Shasta National Forest) | 1000-1500 | 6.30 | 197.4 |
Silvicultural treatments: None. Each plot had a 50% mix of the two seedling stock types used. Due to space limitations, Douglas-fir was planted into 0.33-acre plots while ponderosa pine was planted into the standard 0.5-acre plots. Monitoring of both species will take place on the standard 0.25-acre measurement plots.
Planting density: Contract crews planted 200 trees per acre.
Seedling stock type: 50% containerized; 50% 1-0 bare root seedlings.
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 Happy Camp site.
Figure 2. Seedling diameter by seed source 1 year after planting at the Happy Camp site.
Figure 3. Seedling growth by seed source 1 year after planting at the Happy Camp site.
Silviculture treatment: Ponderosa pine had significantly higher height, diameter, and survival rate than Douglas-fir.
Silviculture-climate interaction: Slight differences in significance of height climate analysis by species but overall same trends.