Klamath Mountains

The Klamath Mountains are characterized by steep, complex topography dissected by a number of large river valleys. The area is noted for its exceptionally rich flora, which results from several factors. First, the Klamath area is a meeting ground for three regional bioclimates and floras—the Pacific Northwest, California, and the Great Basin—and this increases the number of species present (Skinner et al. 2006).

In addition, the area has served as a refugium for millions of years, hence the presence of many woody species near the edges of their ranges or even restricted to the region. Finally, the diversity of geologic substrates is impressive, ranging from acid granite, to basic marble, metamorphosed shale, and chemically unique ultramafic extrusions. As a consequence, the mosaic of vegetation types does not fall neatly into broadly continuous zones or belts, as it does in the Coast Ranges or the Sierra Nevada (Whittaker 1960, Sawyer and Thornburgh 1977).

Pollen and charcoal records dating back to prehistoric times indicate that fire regimes have continually changed in the Klamath Mountains since the last ice age. Climate has been the dominant driver of fires in montane and subalpine Klamath forests. Indigenous people of the bioregion used frequent, low-moderate-intensity fires to promote the production of plants for food and fiber, for ceremonial purposes, and to improve hunting conditions (Long et al. 2016). After the removal and prevention of Native American ignited fires in the mid-1800’s, Euro-American settlers used fire to facilitate travel, clear ground for mining, to aid in hunting, and to improve forage for livestock (Whittaker 1960). Many areas in the Klamath Mountains did not experience major changes in fire regime until the establishment of fire suppression in 1905 (Shrader 1965). Fire suppression was effective in more accessible areas by the 1920s (Fry and Stephens 2006) and in remote areas after 1945 (Taylor and Skinner 1998). Fire occurrence in the bioregion declined dramatically following fire suppression . Even as the number of fires declined, fire size and total area burned have increased since the onset of fire suppression with the proportion of high severity burn area increasing as well (Miller et al. 2012). 

References

Fry, D.L., S.L. Stephens,. 2006. Influence of humans and climate on the fire history of a ponderosa pine mixed-conifer forest in the southeastern Klamath Mountains, California. Forest Ecology and Management 223: 428-438.

Long, J.W., M.K. Anderson, L. Quinn-Davidson, R.W. Goode, F.K. Lake, C.N. Skinner. 2016. Restoring California black oak ecosystems to promote tribal values and wildlife. USDA Forest Service General Technical Report PSW-GTR-252. Pacific Southwest Research Station, Albany, California, USA.

Miller, J.D., C.N. Skinner, H.D. Safford, E.E. Knapp, C.M. Ramirez. 2012. Trends and causes of severity, size, and number of fires in northwestern, California, USA. Ecological Applications 22: 184-203.

Sawyer, J.O., D.A. Thornburgh. 1977. Montane and subalpine vegetation of the Klamath Mountains. Pages 699-732 in M.G. Barbour and J. Major editors. Terrestrial Vegetation of California. John Wiley and Sons, Net Work, New York, USA.

Shrader, G. 1965. Trinity forest. Pages 37-40 in: Yearbook of the Trinity County Historical Society. Weaverville, California, USA.

Skinner, C.N., A.H. Taylor, J.K. Agee, C.E. Briles, C.L. Whitlock. 2006. Klamath Mountains Bioregion. Pages 171-193. In: J.W. Van Wagtendonk, N.G. Sugihara, S.L. Stephens, A.E. Thode, K.E. Shaffer, J.A. Fites-Kaufman, editors. Fire in California’s Ecosystems. University of California Press, Oakland, California, USA.

Taylor, A.H., C.N. Skinner. 1998. Fire history and landscape dynamics in a late-successional reserve in the Klamath Mountains, California, USA. Forest Ecology and Management 111:285-301.

Whittaker, R.H. 1960. Vegetation of the Siskiyou Mountains, Oregon and California. Ecological Monographs 30: 279-338.