Sierra Nevada Lodgepole Pine Forest

This ecological system is widespread in glacial basins at upper montane to subalpine elevations of the central and northern Sierra Nevada and Transverse and Peninsular ranges where cold-dry conditions exist (1800-2450 m [6000-8000 feet] in the north and 2450-3600 m [8000-12,000 feet] in the south). It also occurs on extensive broad ridges and pumice plateaus of the southern Cascades in Oregon (the broad ridges that form the Cascade crest in southern Oregon tend to be dominated by extensive stands of lodgepole pine). Soils are often shallow and coarse-textured. These forests and woodlands are dominated by Pinus contorta var. murrayana with shrub, grass or barren understories. Avalanche as well as tree mortality from insect outbreak and disease, drought and associated wildfire are drivers of community structure and composition. Understories are open, with scattered shrubs and herbaceous species, which do not carry fire should one get started. Trees can be very large and old and can attain diameters of 1.2 m (4 feet). Associated plant species include Arctostaphylos nevadensis, Ceanothus cordulatus, Cercocarpus ledifolius (although not that common, just occasional in drier sites), Chrysolepis sempervirens, Phyllodoce breweri, and Ribes montigenum. Common graminoids include Poa wheeleri, Carex filifolia, Carex rossii, and Carex exserta. Fire-return intervals are many hundreds of years. This system occurs in less severe settings than Mediterranean California Subalpine Woodland (CES206.910) and Northern California Mesic Subalpine Woodland (CES206.911) and is made up of trees that are not usually krummholz. Avalanches are less of a factor except in association with the volcanic peaks. Low-elevation stands of Pinus contorta in the pumice zone of Oregon are included in Rocky Mountain Poor-Site Lodgepole Pine Forest (CES306.960).

These forests and woodlands are dominated by Pinus contorta var. murrayana with shrub, grass or barren understories. Avalanche as well as tree mortality from insect outbreak and disease, drought and associated wildfire are drivers of community structure and composition. Understories are open, with scattered shrubs and herbaceous species, which do not carry fire should one get started. Trees can be very large and old and can attain diameters of 1.2 m (4 feet). Associated plant species include Arctostaphylos nevadensis, Ceanothus cordulatus, Cercocarpus ledifolius (although not that common, just occasional in drier sites), Chrysolepis sempervirens, Phyllodoce breweri, and Ribes montigenum. Common graminoids include Poa wheeleri, Carex filifolia, Carex rossii, and Carex exserta.

Upper montane to subalpine elevations of the central and northern Sierra Nevada and Transverse and Peninsular ranges where relatively cold-dry conditions exist (1800-2450 m [6000-8000 feet] in the north and 2450-3600 m [8000-12,000 feet] in the south). It is often located on benches but also occurs on moderate slopes, and on extensive broad ridges and pumice plateaus of the southern Cascades in Oregon (the broad ridges that form the Cascade crest in southern Oregon tend to be dominated by extensive stands of lodgepole pine). The climate regime is Mediterranean with wet winters (November-April), with precipitation occurring as snow, and dry summers, although summer thunderstorms occur sporadically.

LANDFIRE model information: Disturbance patterns have been poorly studied in Sierran lodgepole pine. Sierran lodgepole has been described as not being a fire type (Barbour and Minnich 2000) or as having long intervals between fires (Keeley 1980, Parker 1986, Potter 1998). Avalanche as well as tree mortality from insect outbreak and disease, drought and associated wildfire are the main drivers of community structure and composition. Somewhat similar wet lodgepole types in the Klamath Mountains and Oregon had a fire-return interval range of 70-100 years. Season of fire is generally late summer to early fall. Stand-replacement fire occurs at long interval, resulting in low stand complexity. Mixed-severity fire occurs when fuel conditions remain moist and result in mixed-age stands. Very infrequently, surface fires can occur. Forest understory is typically sparse with few shrubs and low to moderate herbaceous cover. Fuel is considered sparse (Parker 1986, van Wagtendonk 1991). Stands in the southern Sierra Nevada have been described as self-perpetuating (regeneration from treefall gaps) with long intervals between fires (Keeley 1980, Parker 1986, Potter 1998). Sparse fuels are believed to limit ignition and fire spread (Parker 1986). In contrast, fire history studies from dry subalpine lodgepole pine forest in the southern Sierra Nevada have found moderate fire-return intervals in some stands (Keifer 1991, Caprio 2008 and unpubl. data). Intervals ranged from 31-74 years (Chagoopa Plateau, Sequoia National Park and Palisades Canyon, Kings Canyon National Park). Fire severity was mixed and ranged from understory burns on areas up to 100s of ha to high-severity crown fires in patches up to 10s of ha (FRG of III). Season of fires was late summer or early fall. Seasonal fire scar positions on Chagoopa and Palisades (SEKI) was 40.7% and 15% latewood and 59.3% and 80% dormant, respectively (Caprio unpubl. data). Other important disturbance agents in this system include the lodgepole needle miner, windthrow and stress from extreme climatic events.

This system occurs in glacial basins at upper montane to subalpine elevations of the central and northern Sierra Nevada and Transverse and Peninsular ranges where cold-dry conditions exist (1800-2450 m [6000-8000 feet] in the north and 2450-3600 m [8000-12,000 feet] in the south). It also extends south into Baja California, Mexico, in the San Pedro Martir Mountains.

If present in Oregon, the most likely location is the southern Oregon Cascades. The broad ridges that form the Cascade Crest in southern Oregon tend to be dominated by extensive stands of lodgepole pine (south of Crater Lake and north maybe to Mount Bachelor). There are also relatively large areas of lodgepole pine along the broad crest from Mt. Jefferson to a little ways north of Olallie Butte that may also fit this type better than the Rocky Mountain lodgepole pine type, as these stands are more likely dominated by Pinus contorta var. murrayana than Pinus contorta var. latifolia. Understory species are probably different from those listed, however.