The coastal wood fern (Dryopteris arguta) is an evergreen fern occurring from southern B.C. south to California. In Canada, the species occurs on SE Vancouver Island and several adjacent northern Gulf Islands. The estimated population size is more than 7500 plants covering an area of 1.9 ha. There are records of 13 populations, 9 of which occur at least partially on private land. The species was designated as Special Concern by COSEWIC in 2001 and added to the federal Species at Risk Act Schedule 1 in 2004. In B.C., the species is ranked S2S3 (imperilled to special concern, vulnerable to extirpation or extinction) by the Conservation Data Centre and is on the provincial Blue list. The Conservation Framework has assigned coastal wood fern a conservation priority 2, the second highest priority rank under Goal 3: Maintain the diversity of native species and ecosystems.
The coastal wood fern grows under open forest canopies of Douglas-fir, Garry oak, and/or arbutus, and on rocky coastal bluffs and outcrops. Most populations occur on steep slopes, with moderate to very dry, rapidly drained soils. Threats include habitat loss or degradation from, e.g., residential development, recreational activities, and invasive alien plants. Potential threats include climate change and severe weather in the form of winter windstorms and the potential resulting erosion or sun and wind exposure, and sudden oak death (Phytophthora ramorum), a fungus. The long-term management goal is to maintain all known populations at no less than their current size and to maintain the species? current distribution and area of occupancy in British Columbia. Plan objectives may be met through a combination of initiatives such as habitat protection, stewardship activities to minimize threats, research to address key knowledge gaps, inventory and monitoring of known populations, inventory to determine if there are undocumented populations, and outreach and communication.
Garry Oak Ecosystems Recovery Team. 2010. Management Plan for the coastal wood fern (Dryopteris arguta) in British Columbia. Ministry of Environment. Management Plan (Species at Risk)