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The Distribution of Engelmann Oak (Quercus engelmannii) in California

Informally Refereed
Download (PDF 1.82 MB): https://research.fs.usda.gov/download/treesearch/28457.pdf

Abstract

Engelmann oaks (Quercus engelmannii) only occur in the foothills of San Diego (93 pct of extant stands), Riverside (6 pct), Orange (0.5 pct), and Los Angeles (25 to ≤50 pct; (four) >50 to ≤75 pct; (five) >75 to ≤95 pct; and (six) >95 to ≤100 pct. All areas were field checked for accuracy in boundary and canopy classification. There are approximately 7,300 ha of woodlands in categories five and six; 14,000 ha in categories three and four; and 9,200 ha in categories one and two. Combining these data with USGS Digital Elevation Models suggests that Engelmann oaks are most concentrated on 0° to 10° slopes with southwestern aspects between the elevations of 700 m to 1250 m above sea level. They tend to occur at higher elevations and slightly steeper slopes (5° to 10°) than coast live oaks, but there are no differences in the distribution of the two species relative to slope-aspect. The largest landholder of Engelmann oak stands is the Cleveland National Forest (24 pct of all stands), followed by Spanish Land Grants (29 pct; unbroken large land holdings), Native Americans (7 pct; on Indian Reservations), and the US Marine Corps (6 pct; Camp Pendleton). A large number of small private parcels control the remaining 31 pct of Engelmann oak stands.

Parent Publication

Citation

Scott, Thomas A. 1991. The Distribution of Engelmann Oak (Quercus engelmannii) in California. In: Standiford, Richard B., tech. coord. 1991. Proceedings of the symposium on oak woodlands and hardwood rangeland management; October 31 - November 2, 1990; Davis, California. Gen. Tech. Rep. PSW-GTR-126. Berkeley, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture; p. 351-359