Growth and management of a remnant stand of Engelmann oak at Los Angeles County Arboretum & Botanic Garden

Abstract

Commercial, residential and ranch development combined with pressures from grazing, foraging and pests have decimated Engelmann oak (Quercus engelmannii) populations, resulting in this species being designated as vulnerable by the International Union for Conservation of Nature Red List of Threatened Species^TM. Los Angeles County Arboretum and Botanic Garden has the largest population of Engelmann oak in Los Angeles County and therefore has a responsibility to conserve and manage it, ensuring the grove’s long-term survival. To achieve this goal, the arboretum has adopted a four-phase management program that includes the following: weed abatement; fostering successful establishment of natural recruits; supplementing natural recruits with nursery-grown saplings from field-collected acorns; and using precipitation and temperature data to guide the frequency and quantity of supplemental irrigation during winter, spring and late summer months. History of the plight of Engelmann oaks, observations about the natural history of the arboretum’s population, an overview of our management program, and conservation progress to date are presented.

Parent Publication

• Proceedings of the seventh California oak symposium: managing oak woodlands in a dynamic world

Citation

Henrich, James, E. 2015. Growth and management of a remnant stand of Engelmann oak at Los Angeles County Arboretum & Botanic Garden. In: Standiford, Richard B.; Purcell, Kathryn L., tech. cords. Proceedings of the seventh California oak symposium: managing oak woodlands in a dynamic world. Gen. Tech. Rep. PSW-GTR-251. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 157-164.