Conservation of Rare Serpentine Plants in the San Francisco Bay Area: Current Status and Future Prospects

The conservation of rare plants prioritizes in situ conservation by way of maintaining healthy and stable populations via monitoring and threat management. However, when populations appear to diminish additional effort must be taken to maintain their contribution to biodiversity in their natural habitat via ex situ conservation. This is done through harvesting of seed for propagation for the purpose of later augmentation and reintroduction. However, harvesting of seed from threatened rare plant populations poses a challenge to land managers by way of potentially diminishing or disrupting regeneration. Therefore, germination and propagation protocols must be developed carefully to ensure that impacts are minimal, and that the results can better support the long-term conservation of species.The United States Fish and Wildlife Services’ Recovery Plan for the Serpentine Soil Species of the San Francisco Bay Area identified several serpentine endemics proximal to the Crystal Springs Reservoir in San Mateo County whose conservation needs further study. The San Francisco Public Utility Commission Natural Resources and Lands Management division is responsible for the management of ~63,000 acres of watershed lands which contain populations of three endemic, rare plant species: Fritillaria biflora var. ineziana, Pentachaeta bellidiflora, and Eriophyllum latilobum. Here, I present an analysis of the current conservation status and future prospects for these species. I review the literature concerning endemism, rarity, serpentine ecology, climate modeling, species biology and threats to provide the foundation for the conservation planning of these rare species. Additionally, the reintroductions of the rare species Argyroxiphium kauense and Amsinckia grandiflora, as well as important frameworks are reviewed to identify approaches to rare plant recovery efforts. Finally, a supplemental research chapter concerning Eriophyllum latilobum germination trial results demonstrates the early approaches to identifying appropriate seed propagation methods for conservation planning