California

Kristen Hasenstab-Lehman, C. Matt Guilliams, Santa Barbara Botanic Gardens

Dithyrea maritima (Davidson), or beach spectaclepod, is a dune specialist endemic to coastal dunes from central California, United States, to northwestern Baja California, Mexico. Individuals of this perennial herb spread by rhizomes, forming a diffuse colony of ramets, each terminating in rosette of 1 to several fleshy leaves, and a two-chambered fruit (silicle). It is listed on the California Native Plant Society Rare and Endangered Plant Inventory on list 1B.1 and was listed as Threatened under the California Endangered Species Act. Studied occurrences of the self-incompatible D. maritima have low seed set, though manual outcrosses boost seed production. Knowledge of the distribution of genotypes on the landscape is be a critical first step toward any number of recovery actions. In this study, we sample from approximately 30 individuals from each of eleven samplinglocations spanning the range of the taxon from Morro Bay, CA, USA to San Quintín, Baja CA, MX. We used double digestion RADseq to prepare libraries for high-throughput sequencing, assemble the dataset in ipyrad producing 5092 SNPs, and analyze population genomics of the species. We place the observed population genomic patterns into the context of regional biogeography, and conclude with recommendations for managing the species.

Date Recorded: 
Wednesday, September 11, 2019

Joe Davitt, Institute for Conservation Research, San Diego Zoo Global

Maintaining a plant species’ genetic diversity can contribute to adaptive potential, prevent inbreeding effects, and potentially preserve traits such as drought tolerance and disease resistance, all of which are critical in a changing climate. Seed collections are often the best method of conserving the genetic diversity of rare plant populations ex-situ, however most seed collections are made with no available genetic data from the target species. Ideally, this genetic data would give us a clear picture of which populations are the most critical to conserve and how genetically structured a species’ populations are in relationship to one another, but this can be a time consuming and costly process. Seed collection protocols, such as those published by the Center for Plant Conservation, can inform our general best practices, but as seed collectors we must also infer best practice on a species by species basis. The life history and reproductive biology of the target species, as well as our sampling methods can greatly impact the effectiveness of seed collections to capture the entire target populations’ genetic diversity. Taking all available information about a species into consideration, we can infer the best seed collection methods to ensure genetic conservation.

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Date Recorded: 
Tuesday, September 10, 2019

Christy Powell, Brian Dorsey, San Diego Zoo Global, Huntington Botanical Garden

As the most endangered group of plants on the planet, cycads (Cycadales) face a number of threats to their continued existence. Efforts to preserve these iconic plants (in situ reserves and ex situ collections) could benefit greatly from a better understanding of population genetic dynamics and recent demographic history. We have shown that within the genus Dioon most species likely diverged between 30-80 kya. This very recent divergence along with long generation times suggests the possibility of shared polymorphisms across species and potentially incomplete speciation between accepted taxa. Conversely, the distribution of populations and the pollination/dispersal system suggests that migration rates may be quite low. Determining the relative influence of these processes will better inform conservation efforts. Given the nearly 50 Gb genomes of this group, we are using a hybrid of two RADseq methods to produce high coverage/highly multiplexed reduced representation data sets to assess connectivity, historical demography, and genetic diversity. While data for Dioon is still coming in, we have a pilot study using the same technique to assess the genetic diversity among Encephalartos latifrons plants held in botanical gardens in the USA, which we plan to extend to include wild populations with similar goals.

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Date Recorded: 
Tuesday, September 10, 2019

Dr. Stephanie Steele, San Diego Zoo Global 

The Torrey pine (Pinus torreyana) is a rare, iconic species that occurs naturally in only two locations in Southern California: in coastal San Diego County and on Santa Rosa Island. The species is of particular conservation concern due to prolonged drought which has increased susceptibility of trees to attack by the bark beetle Ips paraconfusus. The Ips beetle has posed a significant challenge for trees in the mainland population in recent years. While Torrey pines harbor a remarkably low level of genetic diversity, it is possible that genetic variation underlies resistance to beetles and thus determines, at least partially, which trees survive. To test this, we are using RNA-Seq to survey functional genetic diversity in Torrey pines that either succumb to mortality by bark beetles or remain asymptomatic. We aim to 1) characterize functional genetic diversity in the species, particularly in defense-related genes, 2) test for genetic differentiation between affected and asymptomatic trees, and 3) identify whether specific genetic variants are associated with survival. This work will offer insight into the adaptive potential of Torrey pines to respond to continued bark beetle outbreaks and will inform future restoration efforts for this iconic species.

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Date Recorded: 
Wednesday, September 11, 2019

Jill Hamilton, North Dakota State University

Species evolutionary potential is tightly linked to both the amount and distribution of genetic variation available through which natural selection may act. Rare species present particular challenges under rapidly changing conditions where the genetic consequences of rarity may limit species ability to adapt to ongoing change. Thus in a rapidly changing environment, maintenance of genetic variation within and across populations becomes an increasingly important target for species conservation. Here, I examine the role genetic rescue may play in the maintenance of a rare species' evolutionary potential. Exhibiting exceptionally low levels of genetic variation, endangered Torrey pine, one of the rarest pines in the world and endemic to California, may represent a candidate for genetic rescue. Restricted to just one island and one mainland population, preliminary evaluation of fitness traits in Torrey pine indicate F1 hybrids, representing a cross between mainland and island trees, are more fit relative to parental populations when grown in a common environment. This suggests that in the short-term, gene flow between populations may provide necessary genetic variation to persist in changing conditions. However, there remain gaps in our understanding of the long-term consequences of genetic rescue. Torrey pine, a poster child for rarity in forest trees, provides an ideal system for which to track the short and long-term consequences of genetic rescue.

Date Recorded: 
Wednesday, September 11, 2019

Kyle L. Gunther, Sula Vanderplank, Jon P. Rebman, Andres Orduño Cruz, & Lluvia Flores-Rentería, San Diego State University, San Diego Natural History Museum, San Diego Zoo Global, Centro de Investigaciones Biológicas del Noroeste

California and the Baja peninsula are home to high levels of floral abundance, diversity, and endemism. Much of this region is part of a biodiversity hotspot and therefore a conservation priority. The Mission Manzanita (Xylococcus bicolor) is endemic to this area, an ecologically and ethnobotanically important shrub, and the sole member of a monotypic genus within Ericaceae. Xylococcus bicolor is narrowly distributed from the middle of Baja California to the Los Angeles area, and has been predicted to experience up to 88% habitat loss due to climate change and development. However, little is known about its population structure, demographics, and genetic diversity, which may be useful information for conservation purposes. In order to fill this gap in knowledge, we are studying these aspects from a genetic perspective. Using a genome skimming technique to reveal thousands of single nucleotide polymorphisms, we are analyzing the population structure, genetic diversity, gene flow, and effective population sizes across the X. bicolor distribution. Preliminary results suggest the presence of intraspecific divergence and population structure, while niche models show loss of suitable habitat using climate change scenarios. We hope our study will provide useful information for land management and conservation decisions.

Date Recorded: 
Wednesday, September 11, 2019

Vanessa Handley, University of California Botanical Garden

University of California Botanical Garden (UCBG) has long been engaged in recovery efforts for State and Federally endangered large-flowered fiddleneck, Amsinckia grandiflora. Initially UCBG staff focused on creating a substantial seed bank for the species and, through nursery augmentation of wild-collections, generated a bank of over 100,000 seed (stored along maternal lines). In 2016, a subset of this seed was deployed for a large-scale reintroduction effort at three sites in San Joaquin County, California. The reintroduction was conducted in partnership with Vollmar Natural Lands Consulting (with funding from the U.S. Bureau of Reclamation) and entailed cultivation and outplanting of over 4000 seedlings. This endeavor - made more challenging by severe terrain and freezing winter rains - resulted in modest persistence in 2017, followed by a banner spring in 2018. UCBG staff and volunteers completed a supplementary round of outplanting this past winter and, by March, all three introduction sites were awash with orange - the Amsinckia grandiflora Super Bloom! This exciting outcome was potentiated by engagement of diverse stakeholders: environmental consultants, multiple agency partners, public and private landowners and UCBG. While the taxon still has a long path to recovery, this preliminary success is a testament to the power of these partnerships. Our recovery implementation strategy will be discussed.

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Date Recorded: 
Friday, May 3, 2019

Martin F. Quigley, University of California-Santa Cruz Arboretum & Botanic Garden

Our mission is to connect people with plants. Our conservation work is dedicated to preservation of biodiversity, and enabling evolutionary processes to continue at the population level. Our primary focus is California, particularly the Central Coast ecosystems. We are developing a 60 acre California Conservation Garden featuring both rare and common plant-community-based gardens, as well as traditional taxonomic collections. We have embarked on a long -erm effort to identify endangered plant populations, study biodiversity, and develop living collections (for research, education and display) of the central coast chaparral, forests, and prairies. We conduct vegetation surveys, map important plant areas (IPAs), and establish long term monitoring-sites for reference populations. The Arboretum has a thriving collecting program and expanding seed bank, collecting wild seed from rare species and distributing them to long-term seed banks in the network. We also assist the California Department of Fish and Wildlife and California Native Plant Society with their mapping and classification of rare natural plant communities. Lately we have been participating in plant rescue operations, such as replanting Dudleyas endangered by poachers from public lands. We are committed to teaching our University students botany, horticulture and field work related to conservation stewardship, restoration and land management.

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Date Recorded: 
Friday, May 3, 2019

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.

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Date Recorded: 
Thursday, May 3, 2018