The Management Strategic Plan for San Diego County requires prioritization and management for edaphic endemic plants, including the five rare plants addressed in this study. These species face low genetic diversity due to reduced population sizes, geographic isolation, and loss of pollinators. To enhance the resilience of these species across their ranges, we must manage threats to increase population sizes, identify potentially suitable habitat to connect existing populations, find or restore new populations, and provide opportunities for shifting distributions due to climate change.
This study identifies and describes geographic areas that support the five edaphic endemic species and their habitat in a design that enhances resilience and provides opportunities for shifting distributions. We developed conceptual models to inform field studies and management, refined soils and vegetation attributes, and assessed regional population structure and threats. We used results to suggest prioritized locations for surveys, management, potential translocation, and additional conservation or acquisition. Project partners (U.S. Geological Survey and San Diego Management and Monitoring Program) modeled suitable habitat for the target species under current and future climate scenarios; we reference models as appropriate.
Project type: General Management
Data steward: Emily Perkins
Investigator: Patricia Gordon-Reedy
Main implementing entity: Conservation Biology Institute
Partner: A & L Western Laboratories; California Department of Fish & Wildlife; San Diego Management and Monitoring Program; San Diego State University; Space and Naval Warfare Systems Command (SPAWAR); The Nature Conservancy; U.S. Fish and Wildlife Service; U.S. Geological Survey
Point of contact: Patricia Gordon-Reedy; Spring Strahm
SDMMP lead: Sarah McCutcheon
Study lead: Spring Strahm
Reports Available: Yes
Draft Report Date: 2018-03-01
Final Report Date: 2018-03-01
Parry's tetracoccus Tetracoccus dioicus
Goal: Maintain or enhance existing Parry's tetracoccus occurrences 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 chaparral and coastal sage scrub vegetation communities.
Regional
NFO
2017
SS
MON-RES-SPEC TETDIO-3
Management units: 3, 8
In 2017, begin field research into soils and habitat relationships and conduct habitat suitability and climate change modeling for Parry's tetracoccus and other edaphic endemic plants to better understand habitat requirements and to identify and prioritize geographic areas important for connectivity, restoration, and range shifts due to climate change and other threats.
Criteria |
Deadline year |
Refined Models and Prioritized Future Survey Locations for Parry's Tetracoccus by 2018 |
2021 |
San Diego thorn-mint Acanthomintha ilicifolia
Goal: Maintain large populations, enhance small populations, and establish new populations of San Diego thornmint or pollinator habitat to buffer against environmental stochasticity, maintain genetic diversity, and promote connectivity, thereby enhancing resilience within and among MUs over the long-term (>100 years) in native habitats.
Regional
NFO
2017
SO
MON-RES-SPEC ACAILI-11
Management units: 3, 4, 5, 6
In 2017, continue field research into soils and habitat relationships and development of habitat suitability and climate change models for San Diego thornmint and other edaphic endemic plants to better understand habitat requirements and to identify and prioritize geographic areas important for connectivity, restoration, and range shifts due to climate change and other threats.
Criteria |
Deadline year |
Refined Models and Prioritized Future Survey Locations for San Diego Thornmint by 2018 |
2021 |
Thread-leaved brodiaea Brodiaea filifolia
Goal: Maintain or enhance existing Thread-leaved brodiaea occurrences 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 grassland and vernal pool vegetation communities.
NFO
2017
SS
MON-RES-SPEC BROFIL-3
Management units: 6, 7, 8
In 2017, continue field research into soils and habitat relationships and development of habitat suitability and climate change models for thread-leaved brodiaea and other edaphic endemic plants to better understand habitat requirements and to identify and prioritize geographic areas important for connectivity, restoration, and range shifts due to climate change and other threats.
Criteria |
Deadline year |
Refined Models and Prioritized Future Survey Locations for thread-leaved brodiaea by 2018 |
2021 |
Otay tarplant Deinandra conjugens
Goal: Maintain or enhance existing Otay tarplant occurrences 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 native and non native grassland vegetation communities.
Regional
NFO
2017
SS
MON-RES-SPEC DEICON-11
Management units: 3
In 2017, continue field research into soils and habitat relationships and development of habitat suitability and climate change models for Otay tarplant and other edaphic endemic plants to better understand habitat requirements and to identify and prioritize geographic areas important for connectivity, restoration, and range shifts due to climate change and other threats.
Criteria |
Deadline year |
Refined Models and Prioritized Future Survey Locations for Otay Tarplant by 2018 |
2021 |
Dehesa nolina Nolina interrata
Goal: Maintain or enhance existing Dehesa beargrass 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 chaparral vegetation communities.
Regional
NFO
2017
SO
MON-RES-SPEC NOLINT-9
Management units: 3
In 2017, begin field research into soils and habitat relationships and conduct habitat suitability and climate change modeling for Dehesa nolina and other edaphic endemic plants to better understand habitat requirements and to identify and prioritize geographic areas important for connectivity, restoration, and range shifts due to climate change and other threats.
Criteria |
Deadline year |
Refined Models and Prioritized Future Survey Locations for Dehesa nolina by 2018 |
2021 |