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BC Conservation Data Centre: Conservation Status Report

Lupinus lepidus
prairie lupine


 
Scientific Name: Lupinus lepidus
Scientific Name Synonyms: Lupinus lepidus var. lepidus
English Name: prairie lupine
   
Provincial Status Summary
Status: S1
Date Status Assigned: April 30, 1996
Date Last Reviewed: April 29, 2015
Reasons: There are only one or two extant sites of Lupinus lepidus in BC, although with appropriate stewardship, it may be possible to stimulate seed bank germination of this taxon. Urbanization and development on southeast Vancouver Island since the turn of the 20th century has caused loss of sites, considerable fragmentation of L. lepidus habitat, and has led to the invasion of exotic species.
 
Range
Range Extent: A = <100 square km
Range Extent Comments: Lupinus lepidus formerly occurred on southeastern Vancouver Island as far north as Somenos Lake near Duncan (last observed in early 1990's), in Koksilah (last seen in 1973), in Saanich (last observed in 1960) and in the Victoria area (last observed in 1993) [Douglas and Ryan 2006]. Currently it only persists in the Sooke hills in two populations, which occur within an area of less than 20 square km.
Area of Occupancy: AC = 1-5
Area of Occupancy Comments: This species' observed area is about 10 small patches in BC, occupying less than .01 square km. The Area of Occupancy using 2 km x 2 km grid analysis is 20 square km (5 grid cells).
 
Occurrences & Population
Number of Occurrences: A = 1 - 5
Comments: There are two extant populations of Lupinus lepidus in the Sooke Hills: five clusters of multiple subpopulations in the Mount Braden and Mount McDonald area (Roemer 2007), and a single cluster of subpopulations on Mount Helmcken (H. Roemer, pers. comm. 2007). An additional 5 populations are believed to have been extirpated (Ryan and Douglas 1996b). It is possible that seedbanks of L. lepidus may persist in areas where the species was observed in the past.
Number of Occurrences with Good Viability / Ecological Integrity: B = 1 - 3
Comments: Both extant populations of Lupinus lepidus are believed to have good viability, although some of their smaller subpopulations may be less viable.
Number of Occurrences Appropriately Protected & Managed: B = 1 - 3
Comments: One extant occurrence of Lupinus lepidus occurs on lands administered by Capital Regional District Parks, but the population is not necessarily appropriately protected and managed to ensure its long-term survival.
Population Size: D = 1,000 - 2,500 individuals
Comments: In 2007, directed inventories of extant sites documented more than 2000 seedlings (Roemer 2007). HOwever, there were no mature individuals observed in 2007.
 
Threats (to population, occurrences, or area affected)
Degree of Threat: Unknown
Comments: Lupinus lepidus is primarily threatened by fire (or lack of) and development. Secondary impacts of fire suppression include Scotch broom encroachment, competition, shading, and changes to soil chemistry. Ryan and Douglas (1996b) state that the taxon may be particularly vulnerable to Cytisus scoparius, which fixes nitrogen and colonizes disturbed xeric sites but is more highly competitive than L. lepidus. Fire suppression has led to increased ingrowth from competing native woody species, which limits habitat for L. lepidus. Suppression of natural disturbance regimes has also led to increased competition from herb and grass vegetation and increased thatch build up, which limits "safe sites" for germination. All of the former L. lepidus sites were likely maintained by periodic fires. Urbanization, infrastructure and other types of development, and habitat loss have been major factors in causing habitat fragmentation and limiting the taxon's dispersal to appropriate habitat. Recreational activity, trampling, trail development, and herbivory from native and introduced species may also threaten L. lepidus. Roadside improvements (Beacon Hill Park) and sewer pipeline installation (Somenos Lake) were responsible for destroying two of the populations. Demographic collapse may also threaten the taxon.
 
Trend (in population, range, area occupied, and/or condition of occurrences)
Short-Term Trend: E = Decline of 30-50%
Comments: Three new populations (Mount Braden, Mount Wells and Mount Helmcken) have been documented since the status report was published in 1996 (Ryan and Douglas 1996b). The Mount Wells population was discovered in 2000 following a fire. Subsequently, a lack of disturbance and ingrowth of Scotch broom led to a decline in and possible loss of this population, which was last observed in 2004 (Douglas and Ryan 2006; Roemer 2007). This represents a 33% loss of sites, but this species is a seed-banker and it is possible it may reappear at Mount Wells in a favorable year, thus the short term trend is essentially unknown.
Long-Term Trend: A = Decline of >90%
Comments: There are seven extirpated or non-verified populations (Ryan and Douglas 1996b). Some of the populations could not be verified because exact locations were not identified, and one of these sites may have been based on misidentification (Fairbarns and Penny 2003; A. Ceska, pers. comm. 2003). In total, four or five of about seven sites have been lost since the turn of the 20th century, which represents at least 57% (substantial) loss of sites. Long term decline in habitat trends is even more substantial. A 95% decline in Garry Oak habitat between 1800 and 1997 has occurred (Lea 2002). This decline has undoubtedly contributed to losses for this species.
 
Other Factors
Intrinsic Vulnerability: A=Highly vulnerable
Comments: Lupinus lepidus is a short-lived perennial, and without periodic soil disturbances or fire, the plants decline over time (Ryan and Douglas 1996b). Declines may be due either to a lack of vigour in adult plants or to competition.
Environmental Specificity: B=Narrow. Specialist or community with key requirements common.
Comments: Lupinus lepidus occurs on xeric, well-drained soils that are low in nutrients. It requires open habitats in dry meadows, rock bluffs, or open scrubland. Without periodic disturbance, L. lepidus does not persist at a site.
Other Rank Considerations:
 
Information Gaps
Research Needs: Important life history and reproductive facts are not known. The impact of re-introducing regular disturbances on competing vegetation and on Lupinus lepidus requires further research.
Inventory Needs: Further inventory is required in newly disturbed areas and some of the historic sites that could not be relocated when the status report was written. Three populations (Mount Braden, Mount Helmcken and Mount Wells) have been documented since the status report was written, which indicates that further inventory may identify overlooked populations. Accurate inventory of Lupinus lepidus is difficult because the species is a seed banker, and populations may reappear after being absent for one or more years, and it may also be monocarpic, with adult plants dying after fruiting (Roemer 2007).
 
Stewardship
Protection:
Management:
 
Version
Author: Maslovat, C. and J.L. Penny
Date: October 23, 2008
 
References
Douglas, George W., and Michael Ryan. 2006. Conservation evaluation of the Prairie Lupine, Lupinus lepidus var. lepidus, in Canada. Can. Field-Naturalist 120(2): 147-152.
Fairbarns, M., and J.L. Penny. 2003. Rare plant locations in Uplands Park, Victoria.
Roemer, H. 2007. A survey for the endangered prairie lupine (Lupinus lepidus) in the Sooke Hills. A project carried out for the Capital Regional District. Victoria, B.C. 28 pp.
Ryan, M., and G.W. Douglas. 1996b. Status Report on Prairie Lupine, Lupinus lepidus var. lepidus, in Canada. Unpubl. rep. submitted to the Comm. on the Status of Endangered Wildl. in Can. Ottawa. 26pp.
 

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. 2017. Conservation Status Report: Lupinus lepidus. B.C. Minist. of Environment. Available: http://a100.gov.bc.ca/pub/eswp/ (accessed Sep 22, 2017).