BC Conservation Data Centre: Conservation Status Report
Sanicula bipinnatifida
purple sanicle
| Scientific Name: | Sanicula bipinnatifida |
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| English Name: | purple sanicle |
| Provincial Status Summary | |
| Status: | S2 |
| Date Status Assigned: | April 30, 1996 |
| Date Last Reviewed: | April 30, 2019 |
| Reasons: | The 20 extant occurrences of Sanicula bipinnatifida are located mainly in municipal and provincial parks that receive heavy recreational use but where no direct development is likely to occur (i.e., the sites are semi-protected). Many of the parks are considering stewardship measures, but implementation may be limited. Urbanization and development in the Victoria area since the turn of the 20th century has caused considerable fragmentation of S. bipinnatifida habitat and has lead to invasions of exotic species. The prognosis for the three private land sites where S. bipinnatifida occurs may be dubious due to upward trends in development. |
| Range | |
| Range Extent: | D = 1,000-5,000 square km |
| Range Extent Comments: | Sanicula bipinnatifida is restricted to southeastern Vancouver Island plus smaller islands in Haro Strait and the Strait of Georgia, including Saturna Island. It occurs as far north as Flora Islet near Hornby Island. If the Flora Islet population is included, the range extent is approximately 3500 square kilometres. |
| Area of Occupancy (km2): | AC = 1-5 |
| Area of Occupancy Comments: | Based on recent CDC records and recent surveys of large occurrences (Parks Canada Agency 2006), the total area of occupancy is estimated at 2-3 ha (0.02-0.03 square kilometres). |
| Occurrences & Population | |
| Number of Occurrences: | B = 6 - 20 |
| Comments: | There are 20 verified extant populations of Sanicula bipinnatifida in B.C. |
| Number of Occurrences with Good Viability / Ecological Integrity: | C = 4 - 12 |
| Comments: | There are nine occurrences with good viability relative to other B.C. populations (Brown Ridge, Mount Tzuhalem Ecological Reserve and south slopes, Cattle Point, Macaulay Point, Holland Point, Mill Hill, Metchosin at Neild Rd., Albert Head, and Seymour Hill/Thetis Lake). |
| Number of Occurrences Appropriately Protected & Managed: | C = 4 - 12 |
| Comments: | In B.C., Sanicula bipinnatifida occurs in five municipal parks (Rithets Bog Conservation Area, Mount Douglas, Glencoe Cove, Uplands [Cattle Point] and Beacon Hill [Holland Point]), three ecological reserves (Trial Islands, Oak Bay Islands [Alpha Islet], and Mount Tzuhalem), two Capital Regional District parks (Mill Hill and Thetis Lake), and four provincial parks (Dionisio Point, Helliwell [on Flora Islet], Discovery Island Marine, and D'Arcy Island Marine). Minimal protection is offered in the parks as a result of recreational and maintenance activities. Ecological reserves (two of which are islands) offer more protection, although the site on Trial Island is within land leased to a radio-communications company. There are three sites on private property (Brown Ridge, Francis King, and Neild Road) and three sites on federal lands (Mount Tzuhalem Indian Reserve, Albert Head, and Macaulay Point). Macaulay Point is owned by the Department of National Defence but is leased to the Municipality of Esquimalt for recreation. The best protection is at Albert Head (owned by the Department of National Defence) due to a lack of access to the public. All the federal properties will be responsible for protection of all species at-risk as described by Canada's Species at Risk Act. Since the islands are more inaccessible to the public, they may provide more protection than mainland Vancouver Island sites. Stewardship plans are beginning to take shape in several of the parks: Glencoe Cove (Concept Plan), Uplands Park (rare plant inventory/mapping and Rare Species Management Plan), Beacon Hill (rare plant inventory/mapping and Management Plan), Dionisio (Master Plan), Helliwell (Ecosystem Based Plans), and Mill Hill and Thetis Lake (CRD Management Plan and Invasive Species Management Guidelines). Purpose Statements have also been formulated for Trial Islands, Oak Bay Islands, and Mount Tzuhalem Ecological Reserves which should help to instigate conservation and management at these sites. Invasive plant species removal has taken place in Rithets Bog Conservation Area, Glencoe Cove, Uplands Park, Trial Island, Alpha Islet, Mount Tzuhalem, and Mill Hill Regional Park. Invasive species removal at Trial Island was not successful because both Cytisus scoparius and Ulex europaeus resprouted from their root crowns. Mill Hill Regional Park is developing trail signage and fencing to limit off-trail recreational use, and rare plant populations in the park are actively monitored (Maslovat 2004; Roemer 2004). The Habitat Acquisition Trust has conducted a good neighbours program with landowners adjacent to Mill Hill Regional Park and Uplands Park, and Saanich Parks has contacted landowners adjacent to Glencoe Cove. |
| Population Size: | E = 2,500 - 10,000 individuals |
| Comments: | Combined counts from each population number about 3700. This includes both flowering and non-flowering individuals. |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | Substantial, imminent threat |
| Comments: | The following threats to Sanicula bipinnatifida are listed in decreasing order of impact (determined by M. Fairbarns, pers. obs.). Habitat fragmentation has lead to vulnerability to demographic collapse and/or genetic impoverishment. Demographic collapse is an imminent threat facing all populations. Four of the 20 occurrences are in high traffic, heavily used parks (the other occurrences are on private land, federal lands, less heavily used park lands, or less heavily used portions of parks). The threats in these parks include recreational activities (by dogs and people), maintenance activities, trail work, and bench installation. Erosion/slumping of banks could also be related to recreational activities. Trampling caused the breakage and uprooting of the single flowering stem known on Mount Douglas in May 2001, although two plants were found in 2004 (M. Fairbarns, pers. obs.). Competition and thatch buildup from invasive alien grasses and forbs, and competition, shading, and changes to soil chemistry from invasive alien shrubs impact S. bipinnatifida to varying degrees at different sites. Landscaping with non-native plants on private property may degrade habitat and alter hydrological patterns. Competition from invasive native shrubs due to fire suppression and to intense fires from accumulated fuels may impact populations. Development of a sludge treatment plant at Macaulay Point, a proposal under consideration by the Capital Regional District Board of Directors, would eliminate part or all of the largest Canadian population of S. bipinnatifida. Two other sites are also being considered for the treatment plant. Historically, urbanization, development, and habitat fragmentation have been major threats, but most sites are no longer directly affected by these pressures. One of the private land parcels on which S. bipinnatifida occurs has recently been developed as a public golf course; however, the layout of the course was designed with the rare plant occurrences in mind. Actual locations may be protected, but the ecosystems in which they occur have been heavily fragmented by the development. Conversely, the owners of another private land site in Metchosin are aware of S. bipinnatifida on their property and do not intend to disturb the site. The area occupied on the property is fairly far from the house and is in a natural state adjacent to other acreages that have a fair amount of intact ecosystem. In the future, the area could see more development such as subdivisions. The human population of metropolitan Victoria has increased from approximately 180,000 in 1966 to 318,000 in 1996 and is projected to increase to more than 400,000 by 2026. The Capital Regional Plan adopted in 1959 led to urban expansion into rural areas surrounding Victoria over the past 44 years, and this pattern of expansion may continue in order to accommodate population increases (Capital Regional District Regional Growth Strategy 2003). |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | G = Relatively Stable (<=10% change) |
| Comments: | One of the subpopulations at Cattle Point has practically disappeared due to slumping, but the other populations in B.C. appear to be relatively stable. |
| Long-Term Trend: | FH = Decline of <30% to increase of 25% |
| Comments: | Approximately six sites have been lost since the turn of the 20th century, which represents about a 23% loss of sites. |
| Other Factors | |
| Intrinsic Vulnerability: | C=Not intrinsically vulnerable |
| Comments: | Sanicula bipinnatifida is not particularly limited in terms of reproduction. Pollinators are likely generalists, and field observations of healthy, reproducing populations over recent years suggest that the species is not intrinsically vulnerable. Ongoing demographic and phenology studies have documented moderate levels of adult survivorship, flowering, and seed production at two populations (Fairbarns, 2005j). |
| Environmental Specificity: | C=Moderate. Generalist or community with some key requirements scarce. |
| Comments: | Sanicula bipinnatifida occurs over of a range of habitats. It occupies mesic, species-rich meadows in Pseudotsuga menziesii-Arbutus menziesii and Quercus garryana-Arbutus menziesii communities, but it also occurs on eroding, well-drained banks along the seashore. |
| Other Rank Considerations: | |
| Information Gaps | |
| Research Needs: | Important life history and reproductive facts for Sanicula bipinnatifida are not known. Pollinators should be identified. Based on ongoing demographic and phenology studies (Fairbarns, 2005j), the major demographic bottleneck appears to be related to juvenile mortality, although recruitment may also be limited by the availability of 'safe sites' for germinants. Future studies should focus on seed germination, recruitment, and juvenile survivorship. |
| Inventory Needs: | Coastal islands and islets, including the Gulf Islands, should be surveyed. Two populations have been documented since the status report was written, and many more plants were identified at Mill Hill during intensive rare plant monitoring (Roemer 2004). |
| Stewardship | |
| Protection: | Stewardship issues should be addressed all sites where Sanicula bipinnatifida occurs, whether the lands are private, federal, provincial, or municipal. Populations on private land should be highlighted for acquisition or protection under conservation covenants. |
| Management: | |
| Version | |
| Author: | C. Maslovat |
| Date: | February 28, 2005 |
| References | |
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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.
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Fairbarns, M. 2005j. Demographic and Phenological Patterns of Sanicula bipinnatifida (Purple Sanicle). Aruncus Consulting, 776 Falkland Road, Victoria, BC.
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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. 2005. Conservation Status Report: Sanicula bipinnatifida. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jul 30, 2024).