The first phase (years 1-2) of this research task focused on genetic and cytological screening to determine potential ploidy and population genetic differences among occurrences within species. Upon completion, an expert panel convened to review results of the genetic studies and develop specific recommendations for each species relative to the MSP management objectives planned for that species. These recommendations included designing appropriate common garden or reciprocal transplant studies to determine the fitness consequences of using seed from different populations to increase population size or establish new occurrences. The recommendations also addressed MSP objectives involving seed banking and seed bulking needs for each species. The expert panel also made recommendations on genetic management of populations, including whether genetic connectivity needs to be enhanced or restored to maintain or increase genetic diversity. Recommended and approved studies will be added in the second phase (beginning in year 3). The following questions were specifically addressed in phase 1:
1. What is the status of documented occurrences?
2. Is there evidence of mixed ploidy levels among or within occurrences?
3. What is current genetic structure among and within occurrences in the MSPA? How vulnerable are the occurrences to genetic drift and loss of genetic diversity and is there gene flow between occurrences?
4. Are there signatures of genetic bottlenecks or lower genetic diversity in populations that have undergone recent reductions due to fire, drought, or other causes, or evidence of local adaptation?
5. Based on the cytological and genetic analysis, what are the recommendations for common garden and reciprocal transplantations, for collecting, bulking and distributing seeds for enhancing existing occurrences, and for establishing new occurrences?
Project type: Genetic study
Investigator: Amy Vandergast; Jon Rebman
Main implementing entity: San Diego Natural History Museum; U.S. Geological Survey, Western Ecological Research Center
Point of contact: Amy Vandergast
Reports Available: Yes
Final Report Date: 2018-11-19
Orcutt's birds-beak Dicranostegia orcuttiana
Goal: Maintain or enhance existing Orcutt's bird's-beak occurrences and establish new occurrences, as needed, to ensure multiple conserved occurrences with self sustaining populations to increase resilience to environmental and demographic stochasticity, maintain genetic diversity, and ensure persistence over the long term (>100 years) in coastal sage scrub vegetation communities.
Management units: 1, 3
In 2017, complete the study begun in 2016 to characterize the population genetic structure, gene flow, and genetic diversity for Orcutt's bird's-beak occurrences (see occurrence table). The study will determine if there is evidence of mixed ploidy levels within or among occurrences; evaluate vulnerability of occurrences to genetic drift and loss of genetic diversity; assess the level of gene flow among occurrences; identify if there are signatures of genetic bottlenecks or low genetic diversity in occurrences that have undergone recent reductions; and look for evidence of local population adaptation. Based on the results of the genetic analyses, management recommendations will include whether common garden and reciprocal transplantations are necessary before proceeding with population enhancement or restoration and will provide specific recommendations for collecting, bulking and distributing seed to enhance existing occurrences or establish new occurrences.
||Use BMPs to collect plant material for genetic samples at Orcutt's bird's-beak occurrences in the MSPA.
||Population Genetic Analysis of 6 Rare Plant Species in San Diego County
||Hold a workshop of scientists, rare plant experts, and land managers to develop management recommendations based upon the results of genetic analyses.
||Evaluate the overall long-term genetic trajectory for Orcutt's bird's-beak.
||Submit project metadata, genetic datasets and analyses, and report with management recommendations to the MSP Web Portal.
|Genetic Study with Management Recommendations Completed in 2017