BC Conservation Data Centre: Conservation Status Report
Abronia latifolia
yellow sand-verbena
| Scientific Name: | Abronia latifolia |
|---|---|
| English Name: | yellow sand-verbena |
| Provincial Status Summary | |
| Status: | S3 |
| Date Status Assigned: | March 31, 2018 |
| Date Last Reviewed: | April 30, 2019 |
| Reasons: | There are 26 extant occurrences of Abronia latifolia in B.C. Less than half of these are estimated to have good viability (however, not all occurrences are assessed). Most occurrences are found in some type of protected area (in national, provincial, and regional parks and in a private conservation covenant). Range extent in BC is estimated at 32,000 to 38,000 square km. Populations are estimated to have declined by 10% over the last 10 years and about 30% since 1925 because of habitat loss caused by the spread of Ammophila arenaria. An estimated 75-80 percent of protected occurrences are likely threatened by ongoing recreation, devlopment, and habitat loss. The species is highly vulnerable because of its irregular dispersal mechanism, highly fragmented populations, and narrow environmental specificity within a relatively scarce habitat. |
| Range | |
| Range Extent: | F = 20,000-200,000 square km |
| Range Extent Comments: | The range extent is 27,774 sq km. It occurs along both coasts of Vancouver Island, on some of the Gulf Islands between Victoria and Comox (e.g., Fairbarns 2004, 2006; Page 2006), and on the east coast of Graham Island on Haida Gwaii (Cheney 2004; Wijdeven 2010). |
| Area of Occupancy (km2): | E = 26-125 |
| Area of Occupancy Comments: |
Using GIS tools, AOO index value is 40 cells (each 4 sq km) or 160 sq km. |
| Occurrences & Population | |
| Number of Occurrences: | C = 21 - 80 |
| Comments: | Twenty-seven occurrences are currently verified or suspected to exist. An additional population from the Cribs Creek area (Cheewhat dune) of the Pacific Rim National Park Reserve is extirpated. |
| Number of Occurrences with Good Viability / Ecological Integrity: | C = 4 - 12 |
| Comments: | About 9 to 12 of the 27 mapped extant occurrences potentially have good viability. Two of these are in Pacific Rim National Park Reserve (five other locations in the park have high recreational use and are subject to beachgrass invasion), two are in undeveloped Provincial Parks (Gibson Marine Park -Flores Island and Sandy Island; locations at Guise Bay (Cape Scott), Guillams Bay (Brooks Peninsula), Catala Island, and Rugged Point have insufficient data to rank viability), and one is in contiguous occurrences at Island View Beach Regional Park, Tsawout First Nation Reserve, and Cordova Spit Municipal Park (Fairbarns 2007). Just over a third (8) have insufficient data to determine viability, however, they are remotely-located, mostly within parks, and thus are presumably found in more pristine habitat conditions. They would be protected from development but not from beachgrass invasion. They are potentially good occurrences as well. Where viability is considered good, it is due to healthy population sizes, ecosystem processes etc in good condition, and location in parks (some with management plans). |
| Number of Occurrences Appropriately Protected & Managed: | D = 13 - 40 |
| Comments: | Twenty-one occurrences are protected to varying degrees in national, provincial, and regional parks and in a private conservation covenant. Fourteen of these are protected from development: seven of these are in Pacific Rim National Park Reserve (1 extirpated), one on Provincial Crown Land managed by DND and Comox Valley Regional District (CVRD), and six are in remote, Provincial Parks (Guise Bay (Cape Scott), Guillams Bay (Brooks Peninsula), Catala Island, Gibson Marine Park -Flores Island, Rugged Point, and Sandy Island). A report from Naikoon Provincial Park on Haida Gwaii appears to be in error, as the population reportedly occurs on private land adjacent to the park (Cheney 2004; Wijdeven 2010). A management plan and conservation strategy for several rare dune species, including Abronia, is being created for the contiguous occurrences at Island View Beach Regional Park, Tsawout First Nation Reserve, and Cordova Spit Municipal Park, known collectively as Cordova Shore (Fairbarns 2007; Page 2010b). A management plan for several rare dune species, including Abronia, is being created for James Island (private land), part of which will be protected by restricted covenant held jointly by The Nature Conservancy of Canada and the North Pender Island Local Trust Committee (Page et al. 2010). Some of the occurrences on Goose Spit at Comox are on Provincial Crown Land leased by DND, some are on land leased by CVRD at Goose Spit Regional Park, and some are on Comox First Nation reserve (Page 2010a). Both DND and CVRD have management plans for Goose Spit that include habitat protection, restoration, and transplanting Abronia, all part of protection measures for the federally-listed sand-verbena moth (Page 2010a). The remaining occurrences are on private land or other regional or municipal parks, which presumably have no management plans or plans that are not being implemented. |
| Population Size: | DE = 1,000 - 10,000 individuals |
| Comments: | Known estimates of population size range from to 2,100 to 7,700 individual plants. Figures are available for only about 11 of 26 extant occurrences. |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | Substantial, imminent threat |
| Comments: | The scope of threats is high, the severity of threats is moderate, and timing (immediacy) is high because of ongoing pressures. About 75-80 percent of protected occurrences are concentrated on the east coast of Vancouver Island and in Pacific Rim National Park Reserve, where development and recreation pressures are greatest respectively. The remaining 20-25 percent of protected occurrences are in more remote wilderness parks on the outer coast, where threats are low. Human threats in the beach and sand dune habitat include development of housing, public and private recreational facilities, heavy recreational use, including trampling by people, horses, dogs, and ATVs, even on remote Haida Gwaii (Fairbarns 2004, 2006, 2007; Page 2006; Wijdeven 2010; Page et al. 2010). Threats on private land, Indian Reserves, and Regional or municipal parks are presumably greater because management plans may not exist or may not be implemented. The attractive yellow flowers of Abronia may cause some losses to casual collecting or digging for garden purposes, and overcollecting for scientific purposes is potential cause for concern for 3-5 small occurrences. Natural threats such as destruction by storms also contribute to seed dispersal and range extension. Beaches are being invaded by European beachgrass (Ammophila arenaria), American beachgrass (Ammophila breviligulata), Scotch broom (Cytisus scoparius), and gorse (Ulex europaeus) (Douglas 2003; Page 2003; COSEWIC 2004; Fairbarns 2006). These exotic species stabilize sand movement, enable invasion of woody plants, and alter the chemistry and organic content of soil. These changes in habitat conditions facilitate invasion by other species that eventually exclude Abronia. Other signifcant threats with some liklihood but with unknown timing include sea level rise related to climate change, and catastrophic loss from Cascadia earthquake-induced tsunamis and/or inundation caused by subsidence. These changes will reduce available habitat where sand dunes cannot migrate inland because of headland limitations. |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | F = Decline of 10-30% |
| Comments: | [F] Populations are estimated to have declined about 10% over the last 10 years because of habitat loss caused by the spread of exotic Ammophila arenaria (European beachgrass) and A. breviligulata (American beachgrass). Ammophila presumably has reduced suitable habitat for Abronia in the province by a considerable amount (Page 2003; Fairbarns 2006). |
| Long-Term Trend: | E = Decline of 30-50% |
| Comments: | [E] Populations are estimated to have declined about 30% over the last 200 years because of habitat loss caused by the spread of exotic dune grasses in BC since 1925. |
| Other Factors | |
| Intrinsic Vulnerability: | AB=Highly to moderately vulnerable. |
| Comments: | Populations are highly to moderately vulnerable because of irregular dispersal and highly fragmented populations. |
| Environmental Specificity: | A=Very narrow. Specialist or community with key requirements scarce. |
| Comments: | Abronia latifolia has very narrow environmental specificity. Its habitat in British Columbia is restricted to upper sand beaches, sand dunes, and sand flats below and above the driftwood zone. These sites are scoured by high tides, winds, and winter storms. |
| Other Rank Considerations: | Populations of Abronia latifolia are often ephemeral because habitat conditions change from year to year, and populations reappear and disappear on an irregular basis. Its seeds remain viable for long periods in the seed bank. Long-term survival may be possible because of the extreme toughness of the fruits that may enable them to persist for years in the seed bank and germinate successfully after long-distance dispersal on ocean currents. It is likely that the seed bank of the ephemeral beach habitat rarely results in large numbers of plants germinating in any given year. Despite the potential for low genetic variability because isolated populations have little chance of outcrossing, experimental work indicates that genetic variation remains high. |
| Information Gaps | |
| Research Needs: | Abronia latifolia has not received as much research attention as the rarer, Abronia umbellata ssp. breviflora, but research done on the latter species can presumably be applied to A. latifolia because of similar growth form, life history, and habitat. The current extent of both exotic species of Ammophila in BC should be delineated with GIS and their rate of spread determined by comparison with historical air photography. This will help quantify habitat loss of dune-dependent native species, the rate of spread of Ammophila, and future threats. Page et al. (2010) identified research as a management priority for conservation areas on James Island. |
| Inventory Needs: | Abronia latifolia can only be detected by making annual surveys of beaches each spring and summer, preferably during the flowering period. Any sites with Abronia latifolia are also potential habitat for A. umbellata ssp. breviflora, so all suitable beaches should be searched. Both unstabilized and partially stabilized dunes behind the foredune should be searched. |
| Stewardship | |
| Protection: | Removal of Ammophila from prime habitat will open up areas for colonization and restore some habitat processes needed for successful establishment of populations. Known stands can be enhanced by control or removal of Ammophila, and fencing on a seasonal basis will help protect populations from recreational impacts. |
| Management: | Eradication of invasive Ammophila arenaria is a challenging problem for land managers (Pickart and Sawyer 1998; Douglas 2003, COSEWIC 2004). To date, chemical, manual, and mechanical control have had only moderate success. With much effort, local areas can be successfully cleared of Ammophila and sand movement restored, but the future challenge will be to apply these techniques or find new ones that are successful at a larger landscape scale. Some populations may require protection from hikers or casual collectors. Abronia umbellata ssp. breviflora has been reintroduced experimentally to former habitat in Oregon (Kaye 2000), and A. latifolia is probably amenable to similar restoration methods. Transplants and seedings of A. umbellata ssp. breviflora had moderate success at some sites and low success at others, but demonstrate that it is possible to re-establish populations of Abronia, at least for the short term. Recommendations by Fairbarns (2007) included education and management training for parks and First Nations staff, public education, controlled access to critical habitat, and habitat restoration. Management and conservation planning by Page (2010b) and Page et al. (2010) includes maintenance of biodiversity and natural processes, habitat restoration, research and education, closure to recreational activity, and coordination with neighboring conservation partners (Parks Canada, Capital Regional District Parks, Tsawout and First Nations). |
| Version | |
| Author: | Christy, J.A.& J.L. Penny |
| Date: | March 22, 2011 |
| References | |
|
Douglas, G.W. 2003b. Status Report on Pink Sand-verbena Abronia umbellata ssp. breviflora in Canada. Unpubl. Rep. submitted to the Comm. on the Status of Endangered Wildl. in Canada. Ottawa. 22pp.
|
|
|
Douglas, G.W., D. Meidinger, and J. Penny. 2002. Rare Native Vascular Plants of British Columbia, 2nd ed. B.C. Conserv. Data Centre, Terrestrial Inf. Branch, Victoria. 358pp.
|
|
|
Fairbarns, M. 2004e. James Island Conservation Assessment. Prepared for The Nature Conservancy of Canada. Victoria, BC.
|
|
|
Fairbarns, M. 2006b. Field survey forms, pink sand-verbena survey. Report to The Nature Conservancy of Canada. Aruncus Consulting, Victoria, B.C. B.C. Conservation Data Centre, Victoria, BC.
|
|
|
Fairbarns, M. 2007. Island View Beach, Central Saanich, Tsawout Reservation, Cordova Spit Municipal Park: Inventory and Management Recommendations for Rare Plants. Aruncus Consulting. Victoria, B.C.
|
|
|
Kaye, T.N. 2000. Experimental reintroduction of pink sand verbena on the Oregon coast: transplanting and seeding. Report to USDA Forest Service, Siuslaw National Forest. Institute for Applied Ecology, Corvallis, OR. 15 pp + maps.
|
|
|
Page, N. and A. Harcombe. 2010. James Island Conservation Areas Management Plan. The Nature Conservancy of Canada, Victoria, BC. 58 pp. + appendices
|
|
|
Page, N.A. 2003. Community and regional scale patterns of native and exotic plant species in sand beaches of Vancouver Island, British Columbia. Unpublished master of science thesis in the Institute of Resources, Environment, and Sustainability, University of British Columbia. 79 pp.
|
|
|
Page, N.A. 2010. Cordova Shore conservation strategy. Unpublished report prepared for Capital Regional District Regional Parks, Tsawout First Nation, and Canadian Wildlife Service, by Raincoast Applied Ecology, Vancouver, BC. 66 pp.
|
|
|
Pickart, A.J. and J.O. Sawyer. 1998. Ecology and restoration of northern Califronia coastal dunes. CA Native Plant Soc., Sacramento, CA. 152 pp.
|
|
|
Wijdeven, Berry. 2010. Survey of selected Haida Gwaii east coast dune Locations. Ministry of Environment, Queen Charlotte. January 2010.
|
|
Please visit the website Conservation Status Ranks for information on how the CDC determines conservation status ranks. For global conservation status reports and ranks, please visit the NatureServe website http://www.natureserve.org/.
Suggested Citation:
B.C. Conservation Data Centre. 2011. Conservation Status Report: Abronia latifolia. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jul 3, 2024).