Ecoregion Spotlight: Southern Cascade Ecoregion

By Ali Aghili

 The Southern Cascade Ecoregion is situated at the southernmost tip of the Cascade Range Southern Cascade ecoregionthat extends from the Canadian border into northern California. Geographically, this ecoregion is distinct because of its volcanic nature. Elevations range from 1,500 to 14,000 feet, precipitation ranges from 20 to 80 inches per year, and temperatures range from 40° to 95° F.

The Southern Cascade Ecoregion is predominantly rural with a mixture of public and private lands. Notable public lands include the Modoc National Forest in the north and Lassen National Forest and Lassen Volcanic National Park in the south. Mt. Shasta and Lassen Peak are the most iconic volcanic mountains. Major human settlements of the area include Shingletown, population 2283, along highway 44; the City of Weed, population 2967, along interstate I-5; and the City of Dorris, population 939 along highway 97. The Southern Cascade Ecoregion generally consists of mixed conifer forested area and non-forested shrubland and grasslands.

Mixed conifer forest

Photo credit: Brett Furnas, CDFW
Montane Mixed Conifer Forest

Three conservation targets have been selected for this ecoregion as part of the State Wildlife Action Plan update. They are the Western North American Temperate Grassland and Meadow, the Western Cordilleran montane-boreal riparian scrub and forest, and the California-Vancouverian Montane and Foothill (Mixed Conifer) Forest. The target ecosystems were selected based on the native species richness, endemism, and vulnerability.

The mixed conifer habitat types in the Southern Cascade ecoregion consists of white fir, Klamath mixed conifer, montane hardwood conifer, Jeffery pine and Ponderosa pine. Species common to this habitat type are: long-toed salamanders, mountain beaver, spotted owl, bald eagle, fisher, long-eared myotis, olive-sided flycatcher, Western tailed frog, and yellow warbler.

One of the major management challenges for this ecoregion is sustaining ecosystem functionality, including those provided from the fire regime (timing, frequency, intensity and extent), while ensuring safety and avoiding catastrophic events.  Strategies to address this issue includes coordination with partner stakeholders to search for mutual solutions by revisiting and updating the current fire management protocols so that the future best management practices of the forest would also embrace measures that benefit fish and wildlife. The goal of conservation strategies developed through the SWAP update process is to benefit the extent and integrity of these target communities by providing diverse niches for wildlife and plants in this ecoregion.

grassland and meadow

Photo credit: Ali Aghili, CDFW
Temperate grassland and meadows

Other important habitats of the Southern Cascade Ecoregion are Temperate grassland and meadows, and Riparian scrub and forest. Temperate grassland and meadows include Great and Basin wild rye, Blue wild rye, one-sided bluegrass – to name a few. Species common to this habitat type are: common garter snake, California vole, willow flycatcher, Cascade frog, and white-tailed kite. The main conservation objectives for this ecosystem are to improve the community structure and composition by controlling invasive plants, and to address the connectivity issues between patches of meadow habitat.

Riparian scrub and forest habitat exists along the rivers and creeks and provide important refuge for terrestrial species as well as shade to maintain water within the acceptable range for native fish, most notably anadromous salmonids. Species common to riparian habitats are: willow flycatcher, bald eagle, Northern river otter, California quail, Western pond turtle, Shasta crayfish, and many bat species. The main conservation objectives for the riparian ecosystem are to increase the extent of this habitat throughout the ecoregion, eradicate  invasive species to optimize native habitats, maintain habitat connectivity, and address the cumulative effect of riparian loss.