Sequoia site in the Experimental Network for Assisted Migration and Establishment Silviculture (ENAMES)
The Sequoia site, part of the Experimental Network for Assisted Migration and Establishment Silviculture (ENAMES) study, has been established in the Sequoia National Forest 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 planting density on reforestation success. The site burned in 2020 and was planted in the spring 2025.
The sequoia site post planting. Pin-flags show the locations of the newly planted seedlings. Photo by Kara Sanghera.
Landowner: U.S. Forest Service
Location: Seqouia National Forest, Western Divide Ranger District
Nearest town: Sequoia Crest, CA
Species: Ponderosa pine (Pinus ponderosa)
Site history: This site burned in the 2020 Castle Fire.
Site characteristics: The site is at an elevation of 7000 ft and faces south, with a gentle slope of about 10–15° throughout most of the plot area (facing north), and a more inclined slope of 20-25° toward the northernmost site border (facing north and northwest). The plots toward the southern border of the site range from 0-5° with a southeast aspect.
The soil is moderately deep and well-drained. It has a clay-based subsoil enriched with aluminum and iron (also known as an Alfisol, based on U.S. Soil Taxonomy) and a fertile topsoil. The mean annual temperature is 47°F (coldest month 23°F, warmest month 70°F). Mean annual precipitation ranges from 630–710 mm. The amount of this precipitation that is snow varies significantly from year to year, with estimates being between 8–40 mm over the past 30 years, trending towards less snow.
This site is usually untraversable until mid to late spring due to snowfall. In the planting year (2025), the snow did not melt until the last week of April, so planting could not commence until the second week of May.
Planting date: May 7, 2025
Contact person:
Marie McLaughlin, Seed Procurement Manager, Pacific Southwest Region
Marianne Emmendorfer, District Planner and Silviculturist, Pacific Southwest Region
Jessica Wright, Research Geneticist, Pacific Southwest Research Station
Christopher Looney, Research Forester, Pacific Southwest Research Station
A newly planted ponderosa pine seedling. Photo by Kara Sanghera.
The sequoia site post planting. Photo by Kara Sanghera.
Site preparation: In 2024, all standing dead trees 8–35 inches in diameter at breast height were removed. This removal averaged of 2 to 3 snags per acre. Dense stands of multiple Ceanothus species were mechanically removed prior before implementation. The remaining vegetation still made it challenging to plant at the planned spacing.
Pre-planting site conditions: The site was relatively well-cleared toward the center of the site. Most of the site being covered in wood chips from logging debris. Toward the northern border, we found significant cover of deerbrush (Ceanothus integerrimus) and plants of the Ribes genus. Toward the southern border, we found significant deerbrush and mountain whitethorn (Ceanothus cordulatus).
Experimental design: This site is a randomized complete block with four replications per treatment applied to 0.5-acre plots.
Assisted migration treatments: The team used the Climate-Adapted Seed 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) | CA Seed Zone 540 (Sequoia National Forest) | 6000-6500 | 1.67 | 274.4 |
Early-century (2011-2040) | CA Seed Zone 534 (Sequoia National Forest) | 5500-6000 | 2.30 | 238.8 |
Mid-century (2041-2070) | CA Seed Zone 531 (Stanislaus National Forest) | 5000-5500 | 2.73 | 219.8 |
Late-century (2017-2100) | CA Seed Zone 531 (Stanislaus National Forest) | 3500-4000 | 4.55 | 304.7 |
Silvicultural treatments: None.
Planting density: Contract crews planted 225 trees per acre, which equates to 12- 13-foot spacing.
Seedling stock type: Styro 10-D
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 Sequoia site.
Figure 2. Seedling diameter by seed source 1 year after planting at the Sequoia site.
Figure 3. Seedling growth by seed source 1 year after planting at the Sequoia site.