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BC Conservation Data Centre: Conservation Status Report

Thuja plicata - Callitropsis nootkatensis / Coptis aspleniifolia Moist Maritime 2
western redcedar - yellow-cedar / spleenwort-leaved goldthread Moist Maritime 2

 
Scientific Name: Thuja plicata - Callitropsis nootkatensis / Coptis aspleniifolia Moist Maritime 2
English Name: western redcedar - yellow-cedar / spleenwort-leaved goldthread Moist Maritime 2
   
Provincial Status Summary
Status: S1
Date Status Assigned: April 01, 2019
Date Last Reviewed: April 01, 2019
Reasons: This small patch ecological community has a small range that is restricted to mountainous terrain on the east side of Vancouver Island. It is uncommon across its range. Cumulative threats are calculated as Very High, and are largely driven by ongoing timber harvest and climate change impacts. Timber harvest presents a Very High threat as this ecological community, and approximately 80% of this ecological community is mapped on private land. Short and long-term declines are significant, and are largely driven by timber harvest in the past 50 years. Disturbances that influence the hydrological patterns of the very moist soils and altered precipitation patterns may have a significant impact on the recovery of this ecological community.
 
Range
Range Extent: D = 1,000-5,000 square km
Range Extent Estimate (km2): 2280
Biogeoclimatic Unit: CWHmm2/07
Range Extent Comments: The range of this ecological community is based on Version 11 of the Biogeclimatic Ecosystem Classification (BEC) map (B.C. Ministry of Forests, Lands and Natural Resource Operations, Biogeoclimatic Ecosystem Classification Map Version 11. August 2018). This ecological community has a small range and is restricted to mountains on the east side of Vancouver Island.
Area of Occupancy (km2): EF = 2-20 kmē
Area of Occupancy Comments: Terrestrial Ecosystem Mapping (TEM) covers 29.5% (673 km2) of the range (B.C. Ministry of Environment, Terrestrial Ecosystem Information System Database (a), accessed 19/03/2019). This ecological community is identified in 0.6% (4.1 sq km) of the mapped area (B.C. Ministry of Environment, Terrestrial Ecosystem Information System Database (b), accessed 19/03/2019). If this proportion of occupancy is extrapolated across the range, the ecological community is estimated to occupy 4.1 to 13.7 km2.
Spatial Pattern: Small patch
 
Occurrences
Number of Occurrences: Rank Factor not assessed
Comments: Element Occurrence mapping has not be done.
Number of Occurrences with Good Viability / Ecological Integrity: Rank Factor not assessed
Percent Area with Good Viability / Ecological Integrity: D = Moderate (11-20%)
Comments: Each TEM polygon was visually inspected for harvesting history using available satellite imagery from 2019. This inspection found that 13.2% (3.0 km2) of the area in the polygons mapped with this ecosystem did not have a harvesting history.

Structural stage information is available for 100% (4.1 km2) of the area mapped as this ecological community (B.C. Ministry of Environment, Terrestrial Ecosystem Information System Database (b), accessed 19/03/2019). Within polygons mapped as containing this ecological community, 45.9% (1.9 km2) is mapped as mature or old forest (structural stages 6 and 7). Since 2008, the year of the most recent photography used for the TEM, 1.0% (0.25 km2) of polygons that contain this community were harvested (B.C. Ministry of Forests, Lands, and Natural Resources Operations and Rural Development, Consolidated Cutblocks Database, accessed 20/03/2019). However, much of the mapping used much older photography so the area with good ecological integrity is likely lower than what is indicated by mapping. Some of the harvested areas may not have been mature or old forest, but second growth stands. The visual analysis described above would be more accurate than the structural stage analysis as it used more recent photography.

The Vegetation Resource Inventory (VRI) has age data for only 13.3% of the area of the polygons mapped as containing this ecological community that have age data (B.C. Ministry of Forests, Lands, and Natural Resources Operations and Rural Development, Vegetation Resource Inventory, accessed 19/03/2019); this percentage is too low be meaningful for analysis.
 
Threats (to population, occurrences, or area affected)
Degree of Threat: A = Very high
Comments: Cumulative threats to this ecological community warrant a Very High threat rating.

Forest harvesting is calculated as a Very High threat to this ecological community. Each TEM polygon was visually inspected for harvesting history using available satellite imagery; 87.7% (21.7 km2) of the area in the polygons mapped with this ecosystem had a harvesting history. Of the area mapped as containing this ecological community 21.5 km2 (78.8%) is privately owned, mostly by timber companies (B.C. Ministry of Forests, Lands, and Natural Resources Operations and Rural Development, Integrated Cadastral Fabric, accessed 20/03/2019).Timber harvest trends are expected to be ongoing on both private and crown land and will likely occur both in old forests and second growth stands. Harvest of old stands will reduce the area with good viability, while the harvest of second growth stands will reduce the area that can recover from previous disturbances. Recovery may be prolonged if altered precipitation and hydrological patterns affect soil moisture regimes and vegetation community composition.
Climate change is calculated as a Medium ? Low threat. Annual precipitation is expected to increase by 4%, though summer precipitation is expected to decrease by 7% (PCIC Plan2Adapt Online Tool, accessed 01/06/2018). These changes may lead to prolonged dry periods during the growing season, and may extend recovery after disturbance. Spring winds with an intensity to damage forests are expected to increase in coastal areas (Haughian et al. 2012). Wind damage may be significant in instances where the surrounding forest matrix does not confer protection when in early seral stages. Winter precipitation is projected to increase by 3% during the 2020's (PCIC Plan2Adapt Online Tool, accessed 01/25/2019). Increases in winter precipitation may impact the winter soil moisture regime of this ecological community. These changes to the hydrological cycle may influence soil conditions and vegetation community composition.
Roads and road construction are a low threat to this ecological community. Within TEM polygons mapped with this ecological community, the Digital Road Atlas identifies a high density of resource roads (3.7 km/km2) (B.C. Ministry of Forests, Lands, and Natural Resources Operations and Rural Development, Digital Road Atlas, accessed 20/03/2019). Roads can impede drainage and alter hydrological patterns, contribute to fragmentation, and spread invasive alien plant species.

Invasive and other problematic species present Low threats to this ecological community. Numerous invasive alien plant species are documented both within polygons mapped as this ecological community and throughout the range of this ecological community (B.C. Ministry of Forests, Lands, and Natural Resources Operations and Rural Development, Invasive Alien Plant Site, accessed 20/03/2019). There is an increased probability of spruce budworm and tree fungal diseases in coastal areas that cover the range of this ecosystem due to climate change (Haughian et al. 2012). These changes will likely affect the entire coast, but the severity is unknown and timing will be over long time periods.

Fires and fire suppression present Low threats. Fires are more frequent in the drier subzones of the Coastal region. Fires may become more frequent with changing climatic conditions. Recovery from fire may be prolonged as species recovery will vary under the future climates. These fires can be mixture of stand-replacing and stand-maintaining fires, producing even-aged and mixed-aged stands (Wong et al. 2003, Dorner and Wong 2003).
 
Trend (in population, range, area occupied, and/or condition of occurrences)
Short-Term Trend: BC = Decline of 70-90%
Comments: Each TEM polygon mapped with this ecological community visually inspected for harvesting history using available satellite imagery (2019). This analysis showed that 87.7% (21.7 km2) of the polygon area mapped with this ecosystem had a harvesting history that largely occurred in the past 50 years.

Terrestrial Ecosystem Mapping (TEM) covers 29.5% (673 km2) of the range (B.C. Ministry of Environment, Terrestrial Ecosystem Information System Database (a), accessed 19/03/2019). Structural stage information is available for 100% (4.1 km2) of the area mapped as this ecological community (B.C. Ministry of Environment, Terrestrial Ecosystem Information System Database (b), accessed 19/03/2019). Structural stage information from TEM projects indicated that 42% of the area of the polygons contained stands that were identified as young forest or younger (structural stages 4 and below). However, harvest has been ongoing since TEM and so the area in structural stages 4 and below is likely higher than indicated by TEM.

The Vegetation Resource Inventory has age data for 13.3% of the polygon area mapped as containing this ecological community (B.C. Ministry of Forests, Lands, and Natural Resources Operations and Rural Development, Vegetation Resource Inventory, accessed 19/03/2019). This percentage is too low to be meaningful for analysis.

Since the time of TEM mapping, 1.0% (0.25 km2) of polygons that contain this community were harvested and recorded in the Consolidated Cutblocks Database (B.C. Ministry of Forests, Lands, and Natural Resources Operations and Rural Development, Consolidated Cutblocks Database, accessed 20/03/2019). However, timber harvest data may be missing in the Consolidated Cutblocks source databases because the RESULTS database does not record harvesting when it occurs on private land, and harvesting and stand age for harvested areas are not consistently recorded in the Vegetation Resource Inventory database. The area of this ecological community represented as mature and old forest is likely lower than what is indicated by mapping, and is confirmed by the visual examination of the polygons mapped as containing this ecosystem.
Long-Term Trend: BC = Decline of 70-90%
Comments: Each TEM polygon was visually inspected for harvesting history using available satellite imagery (2019). Approximately 87.7% (21.7 km2) of the area in the polygons mapped with this ecological community had a harvesting history that appeared to be less than 50 years old.
 
Other Factors
Intrinsic Vulnerability: AB=Highly to moderately vulnerable.
Comments: Research on other coastal forests indicates that ecosystem recovery for major plant species occurs approximately 80 years after harvesting. Full recovery will take much longer than 80-100 years as many plant species remain absent at this time (Banner and LePage 2008). For forest structure, a critical component that supports biodiversity, a significant amount of recovery occurs by 80-100 years. Full recovery of old growth characteristics will take 160-200 years (LePage and Banner 2014). Recovery after disturbance may be prolonged during extended dry conditions. Disturbances that affect the very moist soils, along with altered hydrological and precipitation patterns may prolong vegetation recovery after disturbance.
Environmental Specificity: B=Narrow. Specialist or community with key requirements common.
Comments: This ecological community occurs on relatively high elevations (700-1100 m) with very poor to medium nutrient regimes and very moist soils (Green and Klinka 1994).
Other Rank Considerations: Provincial Parks cover 13.3% (302.5 km2) of the range of this ecological community and 0.0% of the mapped area of this ecosystem are in protected areas (B.C. Ministry of Environment and Climate Change Strategy, BC Parks, Ecological Reserves, and Protected Areas, accessed 20/03/2019).

Private land ownership covers 78.8% (21.5 km2) of the mapped area of this ecological community (B.C. Ministry of Forests, Lands, and Natural Resources Operations and Rural Development, Integrated Cadastral Fabric, accessed 20/03/2019).
 
Information Gaps
Research Needs:
Inventory Needs: Inventory for both variants to supplement the BGC classification as well as locating element occurrences from TEM projects.
 
Stewardship
Protection:
Management:
 
Version
Author: de Groot, A. and E. A. Cameron
Date: April 01, 2019
 
References
B.C. Ministry of Forests, Lands, and Natural Resource Operations. Biogeoclimatic Ecosystem Classification (BEC) Map, WHSE_FOREST_VEGETATION.BEC_BIOGEOCLIMATIC_POLY [ESRI ArcSDE format]. Version 9. Ministry of Forests, Lands, and Natural Resource Operations, Forest Analysis and Inventory Branch, Victoria, B.C. Updated Regularly.
Green, R.N., and K. Klinka. 1994. A field guide to site identification and interpretation for the Vancouver Forest Region. B.C. Minist. For., Res. Branch, Victoria, B.C. Land Manage. Handb. No. 28.
Nuszdorfer, Fred. 1992. Ranking coastal zones: Meeting with Fred Nuszdorfer, May 30, 1992. Lac LaJeune, BC.
 

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. 2019. Conservation Status Report: Thuja plicata - Callitropsis nootkatensis / Coptis aspleniifolia Moist Maritime 2. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 7, 2026).