Klamath Mountains High Elevation Serpentine Forest

EVT 7022Klamath-Siskiyou Upper Montane Serpentine Mixed Conifer Woodland
CES206.914GNRTreeConifer
Summary
This system occurs throughout the Klamath-Siskiyou mountains region above 1500 m (4550 feet) elevation on thin, rocky, ultramafic (gabbro, peridotite, serpentinite) soils in dry-mesic conditions. Not all ultramafic outcrops support distinct vegetation; only those with very low Ca:Mg ratios impact biotic composition. Although ultramafics may be relatively dry and have a moderate to high grass component, they do not burn often where the serpentine syndrome is severe. The problem is not just the calcium:magnesium ratio, but heavy metals and sometimes high clay content limit biomass production. These systems are highly variable and spotty in distribution. Common species include Pinus monticola, Pinus balfouriana, Quercus vacciniifolia, Pinus jeffreyi, Ceanothus pumilus, Arctostaphylos spp., Notholithocarpus densiflorus var. echinoides, Abies magnifica var. shastensis, and Callitropsis nootkatensis. Stands of stunted (up to 12 m [40 feet]) but straight Pinus contorta are also possible. Chamaecyparis lawsoniana communities can occur in this system in mesic and linear riparian zones. Herbaceous-dominated serpentine fens (and bogs) are treated in Mediterranean California Serpentine Fen (CES206.953).
Source: NatureServe Explorer
Vegetation
These systems are highly variable and spotty in distribution. Common species include Pinus monticola, Pinus balfouriana, Quercus vacciniifolia, Pinus jeffreyi, Ceanothus pumilus, Arctostaphylos spp., Notholithocarpus densiflorus var. echinoides (= Lithocarpus densiflorus var. echinoides), Abies magnifica var. shastensis, and Callitropsis nootkatensis (= Chamaecyparis nootkatensis). Stands of stunted (up to 12 m [40 feet]) but straight Pinus contorta are also possible.
Source: NatureServe Explorer
Environment
This system occurs throughout the Klamath-Siskiyou mountains region above 1500 m (4550 feet) elevation on thin, rocky, ultramafic (gabbro, peridotite, serpentinite) soils in dry-mesic conditions. Not all ultramafic outcrops support distinct vegetation; only those with very low Ca:Mg ratios impact biotic composition. Although ultramafics may be relatively dry and have a moderate to high grass component, they do not burn often where the serpentine syndrome [see Kruckeberg (1984)] is severe. The problem is not just the calcium:magnesium ratio, but heavy metals and sometimes high clay content limit biomass production.
Source: NatureServe Explorer
Distribution
This system occurs throughout the Klamath-Siskiyou mountains region above 1500 m (4550 feet) elevation.
Source: NatureServe Explorer
Ecologically Associated Plant Species

Plant species that characterize this ecosystem type, organized by vegetation stratum. These are species ecologically associated with the ecosystem, not confirmed present in any specific area.

Tree canopy

Abies x shastensis, Callitropsis nootkatensis, Chamaecyparis lawsoniana, Pinus balfouriana, Pinus contorta, Pinus jeffreyi, Pinus monticola

Shrub/sapling (tall & short)

Lithocarpus densiflorus var. echinoides, Quercus vacciniifolia

Short shrub/sapling

Ceanothus pumilus
Source: NatureServe Ecological System assessment
Ecologically Associated Animals (5)

Animal species ecologically associated with this ecosystem type based on NatureServe assessment. These are species whose habitat requirements overlap with this ecosystem, not confirmed present in any specific roadless area.

Mammals (4)

Common NameScientific NameG-Rank
Golden-mantled Ground SquirrelCallospermophilus lateralisG5
Long-tailed WeaselNeogale frenataG5
Yellow-pine ChipmunkNeotamias amoenusG5
Bushy-tailed WoodratNeotoma cinereaG5

Reptiles (1)

Common NameScientific NameG-Rank
Western Fence LizardSceloporus occidentalisG5
Source: NatureServe Ecological System assessment
At-Risk Species Associated with this Ecosystem (1)

Species with conservation concern that are ecologically associated with this ecosystem type. G-Rank indicates global conservation status: G1 (critically imperiled) through G5 (secure). ESA status indicates U.S. Endangered Species Act listing.

Common NameScientific NameG-RankESA Status
Siskiyou WhitethornCeanothus pumilusG3?--
Source: NatureServe Ecological System assessment
Component Associations (1)

Plant community associations that occur within this ecological system. Associations are the finest level of the U.S. National Vegetation Classification (USNVC) and describe specific, repeating assemblages of plant species. Each association represents a distinct community type that may be found where this ecosystem occurs.

NameG-Rank
Pinus monticola - Pseudotsuga menziesii / Quercus vacciniifolia - Notholithocarpus densiflorus WoodlandG2 NatureServe
State Conservation Ranks (2)

Subnational conservation status ranks (S-ranks) assigned by Natural Heritage Programs in each state where this ecosystem occurs. S1 indicates critically imperiled at the state level, S2 imperiled, S3 vulnerable, S4 apparently secure, and S5 secure. An ecosystem may be globally secure but imperiled in specific states at the edge of its range.

StateS-Rank
CASNR
ORSNR
Roadless Areas (2)

Inventoried Roadless Areas where this ecosystem is present, identified from LANDFIRE 2024 Existing Vegetation Type spatial analysis. Coverage indicates the proportion of each area occupied by this ecosystem type.

California (2)

AreaForestCoverageHectares
Tom MartinKlamath National Forest2.6%96.3
SiskiyouKlamath National Forest0.4%79.74
Methodology and Data Sources

Ecosystem classification: Ecosystems are classified using the LANDFIRE 2024 Existing Vegetation Type (EVT) layer, mapped to NatureServe Terrestrial Ecological Systems via a curated crosswalk. Each EVT is linked to the USNVC (U.S. National Vegetation Classification) hierarchy through pixel-level co-occurrence analysis of LANDFIRE EVT and NatureServe IVC Group rasters across all roadless areas.

Vegetation coverage: Coverage percentages and hectares are derived from zonal statistics of the LANDFIRE 2024 EVT raster intersected with roadless area boundaries.

Ecosystem narratives and community species: Sourced from the NatureServe Explorer API, representing professional ecological assessments of vegetation composition, environmental setting, dynamics, threats, and characteristic species assemblages.

IVC hierarchy: The International Vegetation Classification hierarchy is sourced from the USNVC v3.0 Catalog, providing the full classification from Biome through Association levels.

Component associations: Plant community associations listed as components of each NatureServe Ecological System. Association data from the NatureServe Explorer API.

State ranks: Conservation status ranks assigned by NatureServe member programs in each state where the ecosystem occurs.