Goal: Maintain or enhance existing Mexican flannelbush 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 vegetation communities.
Management units: 3
In 2017, inspect Mexican flannelbush occurrences on Conserved Lands (see occurrence table) using the regional IMG monitoring protocol to estimate abundance and collect covariate data on tamarisk and other types of threats, determine management needs. After 2017, repeat monitoring every 3 years, unless an occurrence is small (<100 individuals) or faces a high degree of threat, in which case monitor annually.
|IMP-1||Based upon occurrence status and threats, determine management needs including whether routine management or more intensive management is warranted.||in progress|
|IMP-2||Submit project metadata, monitoring datasets and management recommendations to the MSP Web Portal.||in progress|
|Surveys Completed 2017 and 2020 with Management Recommendations||2021|
|Threat Name||Threat Code|
|Altered fire regime||ALTFIR|
Management units: 3
Beginning in 2017, continue routine management actions identified through the IMG monitoring that began in 2014 at Mexican flannelbush occurrences on Conserved Lands (see occurrence table) . Depending on the type and level of threat, management should only be conducted as needed, not necessarily every year, and using BMPs with precautions to do no harm.
|IMP-1||Perform routine management activities such as protecting occurrences from disturbance through fencing and enforcement and controlling invasive non-native plant species =20% absolute cover.||available for implementation||San Diego National Wildlife Refuge: Mother Miguel Mountain|
|IMP-2||Submit project metadata and management data to the MSP Web Portal.||available for implementation||San Diego National Wildlife Refuge: Mother Miguel Mountain|
|Routine Management Completed as Needed Based Upon Monitoring Recommendations||2021|
|Threat Name||Threat Code|
|Altered fire regime||ALTFIR|
2021-2026 Rare Plant Regional Discovery Surveys
Starting in 2021, surveys were conducted on suitable habitat on Conserved Lands to document whether historic plant occurrences were extant and to discover new occurrences for rare plant species. The purpose of these surveys is to refine and update the distribution of these plants in the Management and Monitoring Strategic Plan Area. Voucher specimens and photographs are taken for each occurrence. Some species are already part of the Rare Plant Inspect and Manage Program and any new occurrences for these species will be included in future monitoring. In the next update of the Management and Monitoring Strategic Plan (2027), species not formerly monitored will be evaluated and potentially added to the Rare Plant Inspect and Manage Program. Botanists surveyed for four rare plant species in 2021: San Diego coastalcreeper (Aphanisma blitoides), Blochman’s dudleya (Dudleya blochmaniae), coast wallflower (Erysimum ammophilum), and Orcutt’s bird’s-beak (Dicranostegia orcuttiana). In 2022, botanists surveyed for: San Diego coastalcreeper (Aphanisma blitoides), Baja California oat grass (Sphenopholis interrupta ssp californica), San Diego ambrosia (Abrosia pumila), Wiggins’ cryptantha (Crytantha wigginsii). In 2023, botanists will survey for five rare plant species: Deane’s milkvetch (Astragalus deanei), Parish brittlescale (Atriplex parishii), Mexican flannelbush (Fremontodendron mexicanum), Jennifer’s monardella (Monardella stoneana ), and small-leaved rose (Rosa minutifolia).
Rare Plant Inspect and Manage Monitoring 2014-2026
From 2014-2026, a Management and Monitoring Strategic Plan (MSP Roadmap) monitoring objective for 30 rare plant species is to inspect occurrences to determine management needs. The inspect and manage (IMG) objective is implemented to document the status of rare plant occurrences and assess habitats and threats to develop specific management recommendations. IMG monitoring is implemented by a combination of land managers and contracted biologists in coordination with the SDMMP. Available rare plant data is posted below. New annual updates are typically posted in March. Based upon an evaluation of these data, a 2014-2026 monitoring schedule has been developed for the 30 rare plant species (attached below). Coordinating data collection across the region allows analyses of species and population trends over time and provides a better understanding of the association between habitat and threat covariates and population dynamics.
San Diego National Wildlife Refuge: Mother Miguel Mountain
This three-year project will protect sensitive species, including Mexican flannelbush, and critical habitat on the southwestern slope of Mother Miguel Mountain, while managing public access in a manner that will create within those who visit the site an awareness and appreciation of the need to respect the habitats and species present on the Refuge.
|File name||Lead Author||Year||Type|
|Management Strategic Plan (MSP) 2014 Monitoring Protocol for Rare Plant Occurrences on Conserved Lands in Western San Diego County||San Diego Management and Monitoring Program||2014||report|
|Management Strategic Plan (MSP) 2015 Monitoring Protocol for Rare Plant Occurrences on Conserved Lands in Western San Diego County||San Diego Management and Monitoring Program||2015||report|
Endemic to southern California and northwestern Baja California, Mexico . In the US found only on the northwest side of Otay Mountain in southern San Diego County. Known to occur naturally in 3 canyons in the US and 1 canyon in Baja California.
In MU3, occurs in Cedar, Little Cedar, and Woodwardia Canyons on Otay Mountain. Transplanted occurrence on the San Diego National Wildlife Refuge in Wild Man Canyon, south of the Sweetwater Reservoir .
FE and CR .
Native populations occur in intermittent drainages with closed-cone coniferous forest and southern mixed chaparral habitats . Often grows in association with metavolcanic soils [3, 4; both cited in 1]. Grows on alluvial benches associated with ephemeral drainages and also on the associated canyon slopes . Elevation range is from sea level to 1,000 meters.
Previously considered a member of the Sterculiaceae (cacao) family , but currently is considered a member of the Malvaceae (mallow) family [5,6,7].
Perennial evergreen shrub  that flowers and produces seed each year . Ability to survive fires through 2 strategies: 1) regenerates after fire through sprouts from underground roots and shoots not killed during the fire, and 2) new plants emerge from seeds that germinate following fire.
Flowers from March to June [8; cited in 1]. Seeds are held on the plants in dry pods until the fall and winter months when the capsules open to release seeds .
Showy nature of the flower and presence of nectar pits at the base of the sepals suggest insect pollination . A focused pollination study has not been conducted.
Adverse genetic effects because of the low number of individuals in the Cedar Canyon occurrence, and altered fire regimes—fires that occur at shorter or longer intervals than the natural cycle or fires that may occur during reproductive seasons. Nonnative, invasive plants, including Tamarix sp. (tamarisk or salt cedar) . There is also the potential for impacts to this species’ habitat from border patrol activities conducted by the Department of Homeland Security through road construction and vehicle use.
United States Fish and Wildlife Service Preventing Extinction Grant: A 2006 grant awarded to the San Diego National Wildlife Refuge to fund a project entitled “Distributional Enhancement of Mexican flannelbush” . Five potential areas for introduction were identified on San Diego National Wildlife Refuge and BLM lands in the Jamul Mountains and on Mount McGinty. Refuge staff collected seeds from the Cedar Canyon population in 2007 and planted 19 plants grown from the collected seed at a site on the Refuge in 2009. Contact: John Martin, Wildlife Biologist, San Diego National Wildlife Refuge. Bureau of Land Management Challenge Cost Share Project: In 2007, the BLM began work on a Cost Share Project with researchers from San Diego State University to conduct a habitat site assessment based on the 2007 critical habitat designation. This research will enable BLM to develop appropriate management and monitoring programs in the areas that have occurrences or potential habitat. Principle investigator: is Kathy Williams, Ph.D., Associate Professor of Biology, San Diego State University. USFWS Recommendations: Resurvey historical occurrences and survey potential habitat to determine if there are any other extant native occurrences. Determine the breeding system and pollinators to determine what, if any, bottlenecks in reproductive output are due to these factors. Determine the distribution of genetic diversity at the various occurrences to assist in identifying higher priority occurrences for potential translocation source materials. Identify how the species will adapt to future environmental changes and withstand possible catastrophic events. Establish site and species monitoring protocols to identify how this species is impacted by future fires and how the occurrences will regenerate. This will help determine what management actions are appropriate. Support and provide assistance to the San Diego National Wildlife Refuge in their efforts to introduce new populations to suitable unoccupied habitat. Establish a working group that will coordinate conservation efforts for the species and focus on coordination between federal agencies (e.g., Service, BLM, DHS), MSCP staff (e.g., County of San Diego), Otay Ranch, and Mexico.
 U.S. Fish and Wildlife Services. 2009. “Fremontodendron Mexicanum ( Mexican Flannelbush ) 5-Year Review : Summary and Evaluation.” Carlsbad, California. Agavaceae.” Rancho Santa Ana Botanic Garden Occasional Publications.
 CNPS, Rare Plant Program. 2016. Inventory of Rare and Endangered Plants (online edition, v8-02). California Native Plant Society, Sacramento, CA. http://www.rareplants.cnps.org, accessed 26 August 2016.
 Oberbauer, T. A. 1991. “Unique Soils and Plants of Limited Distribution in the Peninsular Ranges.” Written for Southern California Botanists.
 Reiser, C. H. 1996. Rare Plants of San Diego County. 1996thed. San Diego, California: Aquifer Press.
 Judd, W.S., and S.R. Manchester. 1997. “Circumscription of Malvaceae (Malvales) as Determined by a Preliminary Cladistic Analysis of Morphological, Anatomical, Palynological, and Chemical Characters.” Brittonia 49 (3): 384–405.
 Bayer, C., M.F. Fay, A.Y. Bruijn, V. Savolainen, C.M. Morton, K. Kubitzki, W.S. Alverson, and M.W. Chase. 1999. “Support for an Expanded Family Concept of Malvaceae within a Recircumscribed Order Malvales: A Combined Analysis of Plastid atpB and rbcL DNA Sequences.” Botanical Journal of the Linnean Society 129 (4): 267–303.
 Baum, D.A., S. DeWitt Smith, A. Yen, W.S. Alverson, R. Nyffeler, B.A. Whitlock, and R.L. Oldham. 2004. “Phylogenetic Relationships of Malvatheca (Bombacoideae and Malvoideae; Malvaceae Sensu Lato) as Inferred from Plastid DNA Sequences.” American Journal of Botany 91 (11): 1863–71.
 Munz, P.A. 1974. A Flora of Southern California. Berkeley, California: University of California Press.