BC Conservation Data Centre: Conservation Status Report
Arbutus menziesii / Arctostaphylos columbiana
arbutus / hairy manzanita
| Scientific Name: | Arbutus menziesii / Arctostaphylos columbiana |
|---|---|
| English Name: | arbutus / hairy manzanita |
| Provincial Status Summary | |
| Status: | S1S2 |
| Date Status Assigned: | March 31, 2021 |
| Date Last Reviewed: | March 31, 2021 |
| Reasons: | This ecosystem has a very limited area of occupancy and the range is limited to a few kilometres along the south coast of British Columbia. Elevations are commonly below 400 m and rarely above 1000 m. Threats are mainly residential development, where scenic locations and viewpoints near urbanized areas contribute to real estate values, and the impact of climate change which may be limited due to the drought tolerance of dominant species. Extreme summer droughty conditions may result in loss of these woody species in some localized areas. |
| Range | |
| Range Extent: | E = 5,000-20,000 square km |
| Range Extent Estimate (km2): | 6910 |
| Biogeoclimatic Unit: |
CDFmm/00
CWHxm1/00 |
| Range Extent Comments: | The range of this ecological community consists of the land portions of the CDFmm and CWHxm1 biogeoclimatic units, covering 6910 km2 [BCFLNR 2018]. The climate of this range has long growing seasons, with warm, dry summers and mild, moist to wet winters. The area covers lower elevations along the east side of Vancouver Island and inland along major valleys, the Gulf Islands, and lower elevations of the Sunshine Coast and the Fraser Valley [ENDFLN20BCCA | G94GRE01BCCA]. |
| Area of Occupancy (km2): | C = 0.5-1 kmē |
| Area of Occupancy Estimate (km2): | 0.74 |
| Area of Occupancy Comments: | There are 0.74 km2 of this element mapped in element occurrences (BC Conservation Data Centre 2021). Terrestrial Ecosystem Mapping covers 75% of the land portion of this community's range [ENDMOE01BCCA|ENDMOE02BCCA|ENDFLN20BCCA|M01TEM06BCCA|M08TEM01BCCA]. Field data from some of the mapping projects are not readily accesible. The area of occupancy of this community may be higher than reflected in available mapping as map scales for some projects are too small to capture occurrences of this community. Mapping may under-represent this community due to focus on regional focus on identification and mapping of forest communities dominated by merchantable timber. |
| Spatial Pattern: | Small patch |
| Occurrences | |
| Number of Occurrences: | B = 6 - 20 |
| Comments: | There are 11 occurrences of this ecological community mapped, based on Terrestrial Ecosystem Mapping (BC Conservation Data Centre 2021). The number of occurrences of this community may be higher than reflected in available mapping. Map scales for most projects are too small to capture occurrences of this community. Mapping may under-represent this community due to focus on regional focus on identification and mapping of forested communities dominated by merchantable timber. |
| Number of Occurrences with Good Viability / Ecological Integrity: | U = Unknown |
| Percent Area with Good Viability / Ecological Integrity: | U = Unknown |
| Comments: | Sampled sites always include some alien invasive species and in some cases the combined cover of invasive species is high. |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | AC = Very high - medium |
| Comments: | This ecological community is affected by a number of threats, including ongoing land conversion to urban and residential/agriculture mixes with continued demand for elevated housing sites with good views. Arbutus has high vegetative regeneration and good seed survival in exposed mineral soil, yet hairy manzanita is very slow growing and does not re-establish quickly after disturbance. Both of these species are susceptible to browsing by ungulates. The impact of invasive alien species on this ecological commuity is not well known, but graminoid species which replace the native grasses and perennial forbs are a concern. This ecological community is not of interest to forest harvesting and occurs in isolated locations throughout much of its range. |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | U = Unknown |
| Long-Term Trend: | U = Unknown |
| Other Factors | |
| Intrinsic Vulnerability: | B=Moderately vulnerable |
| Comments: | Arctostaphylos columbiana is slow to recover after disturbance. |
| Environmental Specificity: | B=Narrow. Specialist or community with key requirements common. |
| Comments: | This community occurs at low elevations (rarely over 1000 m) always within a few kilometres of the coast, on dry shallow to bedrock and rocky sites transitional between herbaceous and woodland ecosystems. |
| Other Rank Considerations: | |
| Information Gaps | |
| Research Needs: | |
| Inventory Needs: | |
| Stewardship | |
| Protection: | |
| Management: | |
| Version | |
| Author: | Barton, K.O and J.R. Straka |
| Date: | April 13, 2021 |
| References | |
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B.C. Ministry of Forests, Lands, and Natural Resources Operations. 2012. Biogeoclimatic Map, ABEC_BC [ESRI Interchange format]. Version 8. Minist. of Forests, Lands, and Natural Resource Operations. Forest Analysis and Inventory Branch, Victoria, B.C. ftp://ftp.for.gov.bc.ca/HRE/external/!publish/becmaps/GISdata/PreviousVersions/ (current as of Feb. 10, 2012).
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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. 2021. Conservation Status Report: Arbutus menziesii / Arctostaphylos columbiana. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 10, 2026).