Golden paintbrush (Castilleja levisecta) is listed as threatened and has become regionally extinct in the southern portion of its range due to habitat conversion. A few wild populations remain in Washington and British Columbia. Efforts to conserve the species in Oregon have emphasized wild seed collection across multiple remnant WA populations, agricultural seed increase, plug planting and seeding into restoration sites and prairies, and follow up management (including mowing, burning, and seed addition to increase plant diversity). Concurrent research has demonstrated that the species is a generalist hemiparasite that benefits from having multiple hosts, underscoring the need to maintain or enhance plant diversity at reintroduction sites. In addition, field tests have helped narrow the habitat type in which the species will thrive. Since 2010, the species has established and increased in Oregon dramatically through reintroduction on conserved public and private lands, to over 350,000 plants across 23 populations in 2018. The US Fish and Wildlife Service is currently considering delisting the species due to these recent successes with population establishment.
Recently updated Best Plant Conservation Practices to Support Species Survival in the Wild detail guidelines for seed collection of rare plants. These include multiple aspects to consider in making seed collections regarding target species characteristics, collection timing, seed collection amount, population genetics and maintaining site quality. Here we outline seed collections for two species for which exceptional situations required special considerations for project success. We explore the use of the Best Practices for seed collections of 1) Phemeranthus piedmontanus (Piedmont fameflower), a species with a small population, identification challenges, and the need for multiple visits to sensitive habitat and 2) Macbridea caroliniana (Carolina birds-in-a-nest)¸ where sequential seed set, distance to the field site and a hurricane presented collection challenges.
Michael Way (Royal Botanic Gardens Kew, UK), Clara Holmes (Greenbelt Native Plant Center, USA), and Sean Hoban (The Morton Arboretum)
In 2017, we established a ‘gap analysis working group’ to assess and report the availability and usefulness of online native seed collection data from seven leading online data sources in order to help native seed collectors optimise their targets for additional collections. Volunteers reviewed online data sources and responded to a standardised list of questions to capture their experience of the depth and functionality of the data source. To visualise our findings we transformed results to simple numerical scores and projected on a six-node radar graph within a draft report. In addition, we asked curators of the data sources to fact-check our conclusions. We recommend that collection holders cooperate to publish standardised collection data that can be discovered, mapped, and evaluated using online tools. This will require enhanced cooperation between curators of botanical names, herbarium and seed curators, together with quality communication with the users of seed collections amongst the research, conservation and ecological restoration community. We discuss several innovative solutions addressing these recommendations that include Creative Commons, generalizing longitude and latitude data for widespread dissemination, analysing user communities to develop better tools for collectors, elucidating Seed Transfer Zones, and engaging seed collectors in the development of additional tools to assist seed collections.
Cheryl Birker, Seed Conservation Program Manager and Evan Meyer, Rancho Santa Ana Botanic Garden
Abies bracteata(Bristlecone fir; Santa Lucia fir) is a 12-30 meter tall tree restricted to a small, wildfire prone range in the Santa Lucia Mountains on the central coast of California. While several botanical gardens maintain living specimens, it remains rare in cultivation and until this project, seeds had yet to be conserved in agermplasmrepository for long-term conservation. In 2014 Rancho Santa Ana Botanic Garden (RSABG) partnered with the United States Forest Service to seed bankAbies bracteata, but a number of complications postponed the collection, including low cone production, high seed predation, and cone inaccessibility. The populations have been impacted by years of drought as well as by the 2016 Soberanes fire, which also impeded collecting efforts. In 2017, a maternal-line conservation seed collection was made with the help of a tree climber and some unconventional collecting techniques. Seeds are now stored in the RSABG seed bank, with a backup collection at the National Laboratory for Genetic Resources Preservation and a living collection in production in the RSABG nursery facility. The lessons learned during this collecting effort will help inform future collections ofAbies bracteatafrom additional populations throughout its range.