Story and photographs by Bryce King
The year 2025 marks the 30th anniversary of the Manual of California Vegetation, an indispensable conservation tool for understanding and protecting California’s vegetation communities. To celebrate, CNPS will highlight vegetation alliances, which describe repeating patterns of plants across a landscape. An alliance is defined by the plant species that live there and reflects local climate, soil, water, and other factors.
Atop an ancient coastal terrace just north of the sleepy central coast town of Lompoc, deep in the heartland of the Chumash Tribe, lies the expansive sandy plateau now known as the Burton Mesa. It is home to one of the most range–limited and unique chaparral types found in California—Burton Mesa Chaparral.
This vegetation alliance is defined by the dominance of the rare Purissima manzanita (Arctostaphylos purissima ) and Sand Mesa manzanita (Arctostaphylos rudis). Both of these are California Rare Plant Rank (CRPR) 1B.1 (the rarest possible for a non-extirpated species, or one that hasn’t been rooted out). A plethora of other rare and unique plants can be found throughout this vegetation assemblage: Lompoc yerba santa (Eriodictyon capitatum, CRPR 1B.2), Lompoc ceanothus (Ceanothus cuneatus var. fascicularis, CRPR 4.2), and Vandenberg monkeyflower (Diplacus vandenburgensis, CRPR 1B.1), plus over 500 other plant taxa!
Burton Mesa Chaparral is one of the last remaining members of the Maritime Chaparral group, a constellation of plant communities found on well-drained sandy soils where water is primarily derived from coastal fog drip. Due to their proximity to the coast and often high property values, many of the lands that once were covered with Maritime Chaparral have been highly developed and degraded, leaving the Burton Mesa as one of the few significant stands remaining. The Burton Mesa was partially spared this fate only because a significant portion of the plant community falls within the security buffer of Vandenberg Space Force Base, a military installation dating back nearly 100 years. The Burton Mesa (along with some scattered populations within The Nature Conservancy’s Jack and Laura Dangermond Natural Preserve to the south) represents some of the last stands of this unique vegetation community.
Burton Mesa Chaparral’s global and state rarity is ranked as G1 and S1.2 respectively, meaning it is both critically imperiled worldwide/statewide and threatened. Urban development, resource extraction, climate change, and accelerating military activity all threaten to increase the pressure on this already stressed ecosystem. CNPS recently completed vegetation sampling in this area of California, and is now working alongside partners to create fine–scale vegetation maps to directly assist with the conservation of this community and others like it. Together, we can ensure that the natural beauty and critical role these chaparral ecosystems provide can be protected for future generations.
Bryce King is a Lead Field Botanist with the CNPS Vegetation Program.
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