Klamath Mountains Dry Serpentine Savanna

This ecological system occurs throughout the Klamath-Siskiyou region below 1500 m (4550 feet) on thin rocky soils below winter snow accumulations and typically experiences hot and dry summers. These savannas and shrublands are almost always found on ultramafic soils (gabbro, peridotite, serpentinite), especially on the Josephine Peridotite Formation in the western Klamaths, with very low Ca:Mg ratio. These systems are highly variable and spotty in distribution. This system represents the most xeromorphic of these environments, generally supporting savannas or shrublands in areas with high rainfall amounts (over 130 cm/year) that would usually support closed-canopy forests. Landforms can include rocky ridges and ridgetops, south-facing slopes and river terraces, or gravelly valley bottomlands. These contain mosaics or patches of open-canopy tree-savannas with chaparral understories or shrub-dominated chaparral. Shrubs will often have higher densities than the trees which are more limited due to the rocky/thin soils and are often stunted in growth-form. These can also be short-duration chaparrals in previously forested areas that have experienced crownfires. When present, trees tend to have a scattered, open canopy or can be clustered, over a usually continuous, dense shrub layer, but sometimes with a grassy understory. Pinus jeffreyi or occasionally Pinus attenuata can form a scattered tree layer over bunchgrasses. Dense shrub layers can also be present in some stands, or form their own patches without trees, especially on ridges. Quercus vacciniifolia, Quercus sadleriana (coastal and wetter climate but found on xeric sties), Notholithocarpus densiflorus var. echinoides, Quercus garryana var. fruticosa (drier, inland), Ceanothus cuneatus, Ceanothus pumilus, Arctostaphylos viscida, Arctostaphylos x cinerea, Arctostaphylos canescens, Arctostaphylos nevadensis, Frangula californica, and Garrya buxifolia represent some of the many chaparral shrubs that can be found in these habitats. Perennial grasses such as Festuca idahoensis ssp. roemeri, Achnatherum lemmonii, Melica sp., and Danthonia californica may also be characteristic, although a diverse and often endemic forb component (including rare serpentine endemics) is usually present. This system tends to have lower diversity within stands than in the other serpentine woodland and shrubland systems. Locally occurring, stunted and open stands of Pinus contorta and Pinus monticola on serpentine at low elevation are included in this system. The grassy understory savannas tend to have understory burns, while shrub-dense stands will suffer intense, stand-replacing fires.

Stands contain mosaics or patches of open-canopy tree-savannas with chaparral understories or shrub-dominated chaparral. Shrubs will often have higher densities than the trees which are more limited due to the rocky/thin soils and are often stunted in growth-form. These can also be short-duration chaparrals in previously forested areas that have experienced crownfires. When present, trees tend to have a scattered, open canopy or can be clustered, over a usually continuous, dense shrub layer, but sometimes with a grassy understory. Pinus jeffreyi or occasionally Pinus attenuata can form a scattered tree layer over bunchgrasses. Dense shrub layers can also be present in some stands, or form their own patches without trees, especially on ridges. Quercus vacciniifolia, Quercus sadleriana (coastal and wetter climate but found on xeric sties), Notholithocarpus densiflorus var. echinoides (= Lithocarpus densiflorus var. echinoides), Quercus garryana var. fruticosa (= var. breweri) (drier, inland), Ceanothus cuneatus, Ceanothus pumilus, Arctostaphylos viscida, Arctostaphylos x cinerea, Arctostaphylos canescens, Arctostaphylos nevadensis, Frangula californica (= Rhamnus californica), and Garrya buxifolia represent some of the many chaparral shrubs that can be found in these habitats. Perennial grasses such as Festuca idahoensis ssp. roemeri (= Festuca roemeri), Achnatherum lemmonii, Melica sp., and Danthonia californica may also be characteristic, although a diverse and often endemic forb component (including rare serpentine endemics) is usually present. This system tends to have lower diversity within stands than in the other serpentine woodland and shrubland systems. Locally occurring, stunted and open stands of Pinus contorta and Pinus monticola on serpentine at low elevation are included in this system.

This ecological system occurs throughout the Klamath-Siskiyou region below 1500 m (4550 feet) on thin rocky soils below winter snow accumulations and typically experiences hot and dry summers. These savannas and shrublands are almost always found on ultramafic soils (gabbro, peridotite, serpentinite), especially on the Josephine Peridotite Formation in the western Klamaths, with very low Ca:Mg ratio. These systems are highly variable and spotty in distribution. This system represents the most xeromorphic of these environments, generally supporting savannas or shrublands in areas with high rainfall amounts (over 130 cm/year) that would usually support closed-canopy forests. Landforms can include rocky ridges and ridgetops, south-facing slopes and river terraces, or gravelly valley bottomlands.

The grassy understory savannas tend to have understory burns, while shrub-dense stands will suffer intense, stand-replacing fires.

This system occurs throughout the Klamath-Siskiyou mountains region below 1500 m (4550 feet), but mostly in the western Klamaths on the Josephine peridotite body.