BC Conservation Data Centre: Conservation Status Report
Balsamorhiza deltoidea
deltoid balsamroot
| Scientific Name: | Balsamorhiza deltoidea |
|---|---|
| English Name: | deltoid balsamroot |
| Provincial Status Summary | |
| Status: | S2 |
| Date Status Assigned: | April 30, 2019 |
| Date Last Reviewed: | April 30, 2019 |
| Reasons: | Of the eight extant populations of Balsamorhiza deltoidea in BC, four have less than ten individuals, which predisposes them to extirpation by random events. This leaves only four populations which may be viable, and only three that have at least good viability. Three of these four viable populations enjoy a reasonable measure of protection, but at least 22% of the provincial population is at risk at a single site at Campbell River. The estimated short-term population trend is a 35% to 40% decline over the past ten years, most of it due to an already sharp decline in the Campbell River population. Threats are substantial and imminent, the total population consists of severely fragmented populations between which there is little genetic exchange, and the species is intrinsically vulnerable, with a narrow environmental specificity. Therefore, this species is considered Endangered in BC. |
| Range | |
| Range Extent: | D = 1,000-5,000 square km |
| Range Extent Comments: | The distribution of Balsamorhiza deltoidea in British Columbia is restricted to southeastern Vancouver Island between sea level and 200 m elevation. Most of the populations are within the limits of the Garry oak ecosystem in this region, which has a range extent of 900 square km. However, the second largest population occurs disjunctly near Campbell River, some 180 km to the northwest, where another 100 square km range once existed. The current range extent is 1000-1200 sq km (COSEWIC 2008t). |
| Area of Occupancy (km2): | EF = 26-500 |
| Area of Occupancy Comments: | Balsamorhiza deltoidea plants are typically clustered in small stands, resulting in small areas of occupancy. Based on a 1 km x 1 km grid, the historic area of occupancy was 16 square km, and current area of occupancy is 8 square km (COSEWIC 2008t). Using a 2 km x 2 km grid, the current area of occupancy is 36 square km. Given the small size of occupied habitat and adjacent suitable habitat at extant locations, the 1 km x 1 km grid is more biologically appropriate than the coarser 2 km x 2 km grid (COSEWIC 2008t). |
| Occurrences & Population | |
| Number of Occurrences: | B = 6 - 20 |
| Comments: |
Balsamorhiza deltoidea has been reported from at least 16, and possibly as many as 20 locations in Canada. Eight extant occurrences are known (COSEWIC 2008t), comprised of at least 36 subpopulations. The estimated number of occurrences is assumed to be very similar, as this is a large, showy plant not easily overlooked, and its range coincides with the densely populated areas on Vancouver Island, where additional occurrences would have most likely already been reported. Two re-introduced populations have also been established by The Nature Conservancy of Canada: container-raised seedlings were planted at the Somenos Garry Oak Protected Area and Cowichan Garry Oak Preserve in 2004 and have remained healthy, with the first flowers appearing in 2009 (Nature Conservancy of Canada 2009). |
| Number of Occurrences with Good Viability / Ecological Integrity: | BC = 1 - 12 |
| Comments: | Of the eight extant occurrences, three have very poor viability, and another two have doubtful viability. The latter include one population under severe threat of being eliminated by development and grazing, and another threatened by grazing by wildlife and invertebrates. This leaves only three populations with good viability and another one or two that may or may not survive in the long term. "Poor viability" is based on low numbers of individuals and/or on observations of declining numbers and health (e.g. cessation of flowering). |
| Number of Occurrences Appropriately Protected & Managed: | C = 4 - 12 |
| Comments: | Deltoid balsamroot occurs in five protected areas on southeast Vancouver Island. However, only four of these may be expected to provide a reasonable degree of protection, and only three of the protected populations are considered viable. Protection status of occurrences and respective numbers of plants are: Ecological Reserve (761 plants, plus 253 plants on adjacent private land), Regional Park #1 (166 plants), Regional Park #2 (53 plants), National Historic Site (2 plants), Municipal park (1 plant) [COSEWIC 2008t]. |
| Population Size: | D = 1,000 - 2,500 individuals |
| Comments: | The estimated number of mature individuals capable of reproduction province-wide is 1592 (COSEWIC 2008t). The Campbell River population, formerly the largest in the province, has been reduced from 1700 individuals in 1992 to 345 in 2007. The Mount Tzuhalem population has increased from 344 plants in 1997 to 1014 plants in 2007 and is now the largest in the province, although part of this increase is due to the discovery of new subpopulations. In order of decreasing size, the eight naturally occuring extant population sizes are 1014, 345, 166, 53, 7, 2, and two populations consisting of a single plant (COSEWIC 2008t). |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | Moderate and imminent threat |
| Comments: | On the basis of province-wide population size, the scope and the immediacy of threats are high because the second largest population (Campbell River) is strongly impacted by habitat destruction. Scope and immediacy of threats are also high when the number of populations is considered because the four smallest populations near Victoria are all in poor health and show little or no regeneration due to a variety of factors, including herbivory by vertebrates and invertebrates, direct destruction by people (including trampling and picking the flowers), degraded habitats due to alien plant invasion, and habitat loss to development. The small size of these populations also predisposes them to stochastic events that could quickly eliminate them, and to inbreeding depression. Severity of threats has been classed as "moderate" because there is still hope, although there is a threat of major losses, that the trend is reversible or at least arrestable with ongoing education, management and restoration efforts. |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | E = Decline of 30-50% |
| Comments: |
Short-term trend is not completely understood as no systematic monitoring has been conducted over the years. In addition, the population size estimated by Ryan and Douglas in 1996 (1,907 mature plants from five verified locations) was an underestimation. Three populations have subsequently been rediscovered at historic locations that Ryan and Douglas failed to find (Fort Rodd Hill, Mill Hill and Skirt Hill), and large new subpopulations have been discovered at Mt. Tzuhalem and Thetis Lake. Since all these populations and subpopulations were likely present but undetected in 1996, the total Canadian population at that time probably consisted of approximately 2,600 mature individuals. The Canadian population thus appears to have declined from 2,600 individuals in 1996 to the 1,592 individuals enumerated in the update report of 2007, a decline of approximately 35% - 40% over the 11-year period (COSEWIC 2008t). A large decrease has occurred in the Campbell River population due to habitat destruction (from 1700 plants in 1992 to 345 plants in 2007), and in the much smaller Highland Pacific population (possibly from 70 plants in 1993 to 7 plants in 2007), also due to habitat destruction, and grazing (COSEWIC 2008t). Most other populations appear to have remained relatively stable since 1996. Increases are mainly observed in the most ecologically intact sites, including sites that have the smallest number of plant and animal introductions. Grazing and browsing by mammals and invertebrates appear to be important factors for population changes. Decreases on southeast Vancouver Island are associated with small numbers and with poor vigor. However, in the second largest population (Campbell River) high vigor and good regeneration is reported in the remaining portion of the population despite the destruction of a major part of the occurrence. |
| Long-Term Trend: | D = Decline of 50-70% |
| Comments: | Long-term trend, as measured by the number of occurrences lost, is clearly downward (50%). As measured by the estimated total population in the province, the trend is also downward (probably <50%), but less accurately ascertained. The main factor for the long-term decline is displacement of habitat by development. Slowing down or arresting the decline by intensive management of the remaining viable populations appears possible, but not certain to be successful. Experimental propagation efforts and plantings are underway. |
| Other Factors | |
| Intrinsic Vulnerability: | A=Highly vulnerable |
| Comments: | Balsamorhiza deltoidea is intrinsically vulnerable for the following reasons: 1) It is a plant that takes a relatively long time to reach flowering/fruiting size, and seedset is sparse due to invertebrate seed predation. Little is known about specificity with regards to pollination or seed dispersal but this may also be a limiting factor. 2) The early emerging foliage is generally sought out by herbivores, including slugs, moth larvae ("cutworms"), introduced eastern cottontail rabbits, native deer, and domestic animals. The above-ground parts of a stand of approximately 50 mature individuals was observed to have been completely consumed by domestic sheep, down to a 1 cm stubble, during one growing season. One of the "extant" populations of about 70 plants in a private property has been greatly reduced due to grazing and development. Cattle are also known to graze the species and many populations now extirpated in the Victoria and Duncan areas may have succumbed to grazing, an extremely common land use in the region during early European settlement. 3) Uninformed people are easily tempted to pick the large and attractive flowers. 4) Finally, all populations occupy attractive open spaces, often on south-facing slopes, which are under residential development pressure. |
| Environmental Specificity: | B=Narrow. Specialist or community with key requirements common. |
| Comments: | This is a species which requires either the dry conditions found in the Garry oak ecosystem or, where it occurs in climatically moister areas (i.e. Campbell River), sites with excessively fast draining, gravelly substrates. The latter are very uncommon in the landscape of eastern Vancouver Island. In the Garry oak area, the species usually occupies habitats on steep, south-facing slopes where rock talus accumulates or where there is deeply weathered or fractured bedrock, also habitats with excellent drainage. |
| Other Rank Considerations: | Deltoid balsamroot is a component of the rare and shrinking Garry oak (Quercus garryana) Ecosystem, which coincides with one of the most densely populated areas of British Columbia. Less than 5% of the original extent of the Garry Oak Ecosystem is left (Lea 2002) and all but its formally protected portions are under pressure for residential development. |
| Information Gaps | |
| Research Needs: |
Research into the causes of continuing decline in disturbed sites and small populations is needed to inform restoration efforts, especially for restoration at those sites from which the species has disappeared. Another urgent research need is experimentation on propagating and re-introducing plants to natural or near-natural habitats. Transplanting and reintroduction of juvenile plants has met with varying success at the Campbell River site. Systematic monitoring of extant populations is needed to more exactly determine trends. An apparently successful propogation and re-introduction project has been undertaken by the Nature Conservancy of Canada, in which seed was collected from Mt. Tzuhalem Ecological Reserve and propogated at the nursery at the Cowichan Garry Oak Preserve. Seedlings subsequently planted at both the Somenos Garry Oak Protected Area and the Cowichan Garry Oak Preserve have survived, and flowered at Somenos for the first time in 2009 (Nature Conservancy of Canada 2009; T. Fleming pers. comm. 2009). |
| Inventory Needs: | Inventory needs are relatively modest compared to most other rare species, as there are very few populations with uncertain status (Cape Mudge and rumoured additional former or present sites near Duncan). Monitoring is more critical, as mentioned above. |
| Stewardship | |
| Protection: | Except for a very small, non-viable population, only two extant sites, Campbell River and Highland Pacific, occur outside areas with protection status. Campbell River is the second largest population in the province, even after substantial reduction by development. Nearly all of the plants in this population are on First Nations lands, where until 2005 no substantial efforts to protect them were underway, although some efforts of reintroduction are occurring on the adjacent municipal lands. As of 2005, however, the Campbell River Indian Band is committed to managing for the population's persistence and is in consultation with the Nature Conservancy of Canada regarding the plants and their habitat (T. Ennis, pers. comm. 2005). The remaining population has been fenced to protect it from surrounding roads and development (COSEWIC 2008t). |
| Management: | Among management needs for the populations with protection are: preventing further grazing damage; invasive species control on a regular, ongoing basis, for grasses and forbs as well as shrubs; enforcement of protected areas rules, and public education. Removal of Scotch broom on a regular basis is especially crucial, since the species is capable of quickly recolonozing sites from a long-lived seedbank. If Scotch broom is allowed to re-establish itself, even small populations may quickly replenish this soil seedbank and reverse the benefits of many years of clearing. Management needs on private land would include efforts toward landowner agreements or covenants and their subsequent enforcement. |
| Version | |
| Author: | Roemer, H., J. Penny and S. Hartwell |
| Date: | August 04, 2009 |
| References | |
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COSEWIC. 2008t. COSEWIC assessment and update status report on Deltoid Balsamroot Balsamorhiza deltoidea in Canada. Comm. on the Status of Endangered Wildl. in Can. Ottawa. In press.
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Lea, E. 2002. Historical Garry Oak ecosystems of Greater Victoria and the Saanich Peninsula. 1:20,000 scale maps. Prepared for Garry Oak Ecosystems Recovery Team by Terrestrial Inf. Branch, B.C. Minist. Sustainable Resour. Manage., Victoria.
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Nature Conservancy of Canada. Deltoid balsamroot makes a comeback in Cowichan Valley. Menziesia, Summer 2009. Vol 14 no. 3. p. 4.
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Roemer, Hans. 2002. A plant species inventory with emphasis on rare species: Fort Rodd Hill/Fisgard Lighthouse National Historic Sites. Rep. prepared for Parks Can., August 2002. 19pp. + app. and photos.
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Ryan, M., and G.W. Douglas. 1996a. Status Report on Deltoid balsamroot, Balsamorhiza deltoidea, in Canada. Unpubl. rep. submitted to the Comm. on the Status of Endangered Wildl. in Can. Ottawa. 30pp.
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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. 2009. Conservation Status Report: Balsamorhiza deltoidea. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 10, 2026).