Maritime Chaparral in Critical Danger

S.E. Vanderplank, J.T. Burgess and J. Riley

Published May 2024 in International Oaks No. 35: 71–78

Abstract

Colonet Mesa is home to the only significant outcrops of maritime chaparral in all of Baja California (Mexico). Once a more extensive habitat on the western edge of the mesa, maritime chaparral is now restricted to just a handful of small outcrops in sandy soils on the clay mesa. The plant composition is unique and includes species of conservation concern such as Salvia brandegeei. Environmental dwarfism has reduced these shrubs to less than

80 cm in height, and at times less than 50 cm, forming a unique elfin forest of chaparral shrubs. Individuals of the rare scrub oak Quercus dumosa were documented growing in these same conditions in 2015, but by 2021 they had been entirely extirpated. The conservation of these outcrops should be a priority for biodiversity conservation in Baja California and the California Floristic Province in Mexico. A conservation plan for Q. dumosa is urgently needed.

Keywords

Quercus dumosa, Colonet Mesa, range limits, conservation, Baja California

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