COSEWIC Status Appraisal Summary on the Twisted Oak Moss Syntrichia laevipila in Canada - 2014

Special concern
2014


Document Information

COSEWIC
Committee on the Status
of Endangered Wildlife
in Canada

COSEWIC logo

COSEPAC
Comité sur la situation
des espèces en péril
au Cananda

Committee on the Status of Endangered Wildlife in Canada (COSEWIC) status reports are working documents used in assigning the status of wildlife species suspected of being at risk. This report may be cited as follows:

COSEWIC. 2014. COSEWIC status appraisal summary on the Twisted Oak Moss Syntrichia laevipila in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xviii pp. (Species at Risk Public Registry website).

Production note:

COSEWIC acknowledges Karen Golinski for writing the status report on the Twisted Oak Moss, Syntrichia laevipila prepared under contract with Environment Canada. This report was overseen and edited by René Belland, Co-chair of the Mosses and Lichens Specialist Subcommittee.

For additional copies contact:

COSEWIC Secretariat
c/o Canadian Wildlife Service
Environment Canada
Ottawa, ON
K1A 0H3

Tel.: 819-938-4125
Fax: 819-938-3984
E-mail: COSEWIC E-mail
Website: COSEWIC

Également disponible en français sous le titre Sommaire du statut de l’espèce du COSEPAC sur la Tortule à poils lisses (Syntrichia laevipila) au Canada.

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COSEWIC Assessment Summary

Assessment Summary - November 2014

Common name
Twisted Oak Moss
Scientific name
Syntrichia laevipila
Status
Special Concern
Reason for designation
This moss occurs from British Columbia and Washington southward to California. The Canadian populations, which are at the northern limits of the species’ range in western North America, occur only in the area of southeastern Vancouver Island and the Gulf Islands. The species is known from more than 90 sites where it is largely restricted to the bark of trees, especially Garry Oak. This species is never dominant where it grows, nor is it frequent in large oak stands. The major threat to the species is the removal of mature Garry Oak. Without land management practices that build and preserve Garry Oak populations, this threat would result in the extirpation of most populations of this species.
Occurrence
British Columbia
Status history
Designated Special Concern in May 2004. Status re-examined and confirmed in November 2014.

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COSEWIC Status Appraisal Summary

Scientific Name:
Syntrichia laevipila
English Name:
Twisted Oak Moss
French Name:
Tortule à poils lisses
Population:
Syntrichia laevipila Brid.
Range of occurrence in Canada:
Range of occurrence in Canada: British Columbia

Status History

COSEWIC:
Designated Special Concern in May 2004. Status re-examined and confirmed in November 2014.

Evidence

Wildlife species:

Change in eligibility, taxonomy or designatable units:
No

Explanation:

The eligibility, taxonomy and designatable units of Twisted Oak Moss in Canada have not changed since the last status assessment (see Mishler 2007, Tropicos 2013). However, a taxonomic study of the Syntrichia laevipila - Syntrichia pagorum complex published in 2004 concluded that S. laevipila and S. pagorum are the same taxon based on the high degree of inter-gradation among taxonomic characters (Gallego et al. 2004). In concurrence with McIntosh (COSEWIC 2004), varietal status for S. laevipila var. meridionalis (Schimp.) Wijk & Margad. was similarly rejected. Mishler (2007) followed Gallego et al. (2004) in his treatment of S. laevipila in the Flora of North America: he synonymized S. pagorum and S. laevipila var. meridionalis with S. laevipila, but noted the need for further examination.

While these changes do not affect our understanding of Twisted Oak Moss in Canada, the more inclusive concept effectively expands its range elsewhere, particularly in the United States, where it is now known from the west (Washington, Oregon, California, Nevada, Arizona, Colorado, New Mexico), Midwest (South Dakota, Nebraska, Kansas, Missouri, Ohio), south (Oklahoma, Texas, Arkansas, Louisiana, Kentucky, Tennessee, Alabama, West Virginia, Maryland, Virginia, North Carolina, South Carolina, Georgia), and northeast (Connecticut) (Mishler 2007).

Range

Change in extent of occurrence (EO):
Yes
Change in index of area of occupancy (IAO):
Yes
Change in number of known or inferred current locations:
(Use the IUCN definition of “location”.)
Unknown
Significant new survey information:
Yes

Explanation:

In Canada, Twisted Oak Moss is currently known from 28 occurrences (Table 1). Twenty-seven are located on southeastern Vancouver Island and the adjacent Gulf Islands of British Columbia. One is found in Vancouver (Figure 1).

Based on contemporary criteria for what constitutes an occurrence (i.e., that--with limited exceptions--occurrences / populations must be separated by > 1 km) (NatureServe 2004), the number of known occurrences of Twisted Oak Moss in Canada when the status report was published in 2004 was 31 (COSEWIC 2004). An occurrence may consist of several “sub-occurrences” (See Table 1). Between 2004 and 2010 four new records were contributed by Terry McIntosh and Wynne Miles (BCBRT and GOERT 2010, Parks Canada 2011). However, only one of the records constituted a new occurrenceNote a of Range. One occurrence is extirpated (Langford). Therefore, based on current knowledge the number of extant occurrences is 28 (Table 1).

Twenty additional records were contributed by McIntosh (with Kella Sadler) and by Steve Joya between 2010 and 2013. Most of the new records are located < 1 km from known occurrences. This resulted in five existing occurrences effectively expanding in area, and 10 previously defined occurrences being amalgamated into three larger occurrences. Four of these recent records represent new occurrences: two of these (one in Vancouver and the other in Nanoose) are situated outside the previously defined extent of occurrence (EO).

With the addition of the new occurrences, the new EO estimate is 4600 km², which is more than double the previous estimate of 1890 km² (COSEWIC 2004). Extirpation of the Langford occurrence did not affect the EO.

The index of area of occupancy (IAO) of Twisted Oak moss is currently estimated to be 112 km², compared to < 20 km² in 2004. The substantial increase results from the addition of 24 records since 2004.

 Whereas prior to 2010 Twisted Oak Moss had been found almost exclusively on Garry Oak trees (Quercus garryana)in BC (COSEWIC 2004), recent observations by Joya demonstrate that in nine records (10% of known) Twisted Oak Moss was found on other substrates (see Table 1). This suggests that Twisted Oak Moss may be able to persist on substrates other than Garry Oak tree trunks at some sites. Note, however, that in most of these cases, Garry Oak trees were present nearby; an epiphytic source population may be required for persistence on alternative substrates.

Notes of Range

Note a of Range

The other occurrence reported as new (Camosun College, Lansdowne Campus) was located < 1 km from a known occurrence at the intersection of Lansdowne Rd. and Cadboro Bay Rd.

Return to note a referrer of Range

Population Information:

Change in number of mature individuals:
Unknown
Change in population trend:
Unknown
Change in severity of population fragmentation:
Unknown
Change in trend in area and/or quality of habitat:
Unknown
Significant new survey information
Yes

Explanation:

Despite new records of Twisted Oak Moss having been reported since the status report was published in 2004, the number of mature individuals is not known. Similarly, nothing is known about population trends or trends in area or quality of habitat: less than half of the new records included data on population size or habitat, and only two of the 31 sites where Twisted Oak Moss was reported from in the 2004 status report have been revisited. The survey of known sites that was scheduled to be completed in 2012 (BCBRT and GOERT 2010, Parks Canada 2011) has not yet commenced.

Most sites where Twisted Oak Moss occurs have not been visited for > 10 years so the true extent of population fragmentation is unknown. However, based on known information > 50% of its total area of occupancy is in habitat patches that are very small and are separated from other habitat patches by long distances (IUCN 2014).

Threats:

Change in nature and/or severity of threats:
Yes

Explanation:

Previously described threats to Twisted Oak Moss include direct removal of individual host trees (or branches), loss of host trees as a result of habitat degradation, lack of host tree recruitment, and air pollution (COSEWIC 2004, BCBRT and GOERT 2010, Parks Canada 2011). All of these threats remain. However, an increase in substrates / species of trees on which Twisted Oak Moss grows means potential lack of Garry Oak recruitment may be slightly less critical to its survival in Canada than was previously thought.

Occurrences not located in parks or on provincial Crown land are highly threatened by urban development. In the long term, several occurrences could be eliminated by lack of recruitment of host trees, especially in areas where the surrounding habitat is no longer “natural”, or they could be eliminated by air pollution in urban areas.

The meaning of the term location for the purpose of COSEWIC assessments has changed since 2004. At that time location (equated with population) was less formally defined than it is now. The current assessment uses the IUCN (2014) definition of location: “a geographically or ecologically distinct area in which a single threatening event can rapidly affect all individuals of the taxon present.” The emphasis on threats requires careful analysis of factors that could eliminate occurrences. The “number of locations” is difficult to define for this species because the varying scale of the threats makes it difficult to predict which threat is most critical, especially where occurrences span areas with several forms of land ownership and plants occupy more than one substrate.

Protection:

Change in effective protection:
No

Explanation:

Twisted Oak Moss was designated as a species of Special Concern by COSEWIC in May 2004. It was subsequently added to Schedule 1 of the federal Species at Risk Act (SARA) in 2005. Only one occurrence is known from federal lands; it is located at the Canadian Forces Maritime Experimental Test Ranges (CFMETR) at Nanoose Bay, on Vancouver Island (COSEWIC 2004, BCBRT and GOERT 2010, Parks Canada 2011).

Thirteen additional occurrences of Twisted Oak Moss in BC may be afforded some form of protection because they are wholly or partially located within provincial parks, provincial ecological reserves, regional park reserves, Nature Conservancy of Canada preserves, municipal parks, or city parks. However, none of these places are explicitly managed for the persistence of Twisted Oak Moss populations.

Rescue Effect:

Change in evidence of rescue effect:
No

Explanation:

Although Twisted Oak Moss occurs in the nearby San Juan Islands of Washington, there is no evidence of a rescue effect.

Quantitative Analysis:

Change in estimated probability of extirpation:
No

Explanation:

Details: The probability of extirpation cannot be estimated owing to lack of data.

Summary and Additional Considerations: 

Twisted Oak Moss is characteristic of Garry Oak ecosystems, which are one of the most threatened native ecosystems in Canada (COSEWIC 2004). The Canadian portion of the population occurs at the northernmost extent of its range in North America. Many new sites have been discovered in BC since 2004. We now know that Twisted Oak Moss may occasionally occur on materials and species of trees other than Garry Oak. However, there is still very little data on population sizes and characteristics, geographical distribution, or habitat conditions. A substantial amount of data and information should be generated by the execution of objectives defined in the management plan for Twisted Oak Moss (BCBRT and GOERT 2010, Parks Canada 2011).

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Acknowledgements:

Steve Joya provided numerous new records. Judith Harpel shared information on populations in the United States. Marta Donovan and Terry McIntosh reviewed the database of records, helped define occurrences, and offered useful comments. Terry McIntosh facilitated access to data from the Nanoose Bay / Notch Hill occurrence located on federal government land; Tracy Cornforth granted permission for the data to be used in this report.

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Authorities Contacted:

Lyn Baldwin, Thompson Rivers University, Kamloops, BC

René Belland, Devonian Botanic Garden, and Department of Renewable Resources, University of Alberta, Edmonton, Alberta

Tracy Cornforth, CFB Esquimalt, BC

Brenda Costanzo, Terrestrial Conservation Science Section, BC Ministry of Environment, Victoria, BC

Marta Donovan, British Columbia Conservation Data Centre, BC Ministry of Environment, Victoria, BC

Judith Harpel, University of British Columbia Herbarium, Beatty Biodiversity Museum, Vancouver, BC

Steve Joya, University of British Columbia Herbarium, Beatty Biodiversity Museum, Vancouver, BC

Olivia Lee, University of British Columbia Herbarium, Beatty Biodiversity Museum, Vancouver, BC

Terry McIntosh, Vancouver, BC

Wynne Miles, Victoria, BC

Mike Ryan, BC Ministry of Forests, Lands and Natural Resource Operations, Kamloops, BC

Kella Sadler, Canadian Wildlife Service, Environment Canada, Pacific and Yukon Region, Delta, BC

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Information Sources

BC Conservation Data Centre (BC CDC). 2013. BC Species and Ecosystems Explorer. BC Ministry of Environment, Victoria, BC. [Web application]Syntrichia laevipila (Last accessed September 25, 2014)

British Columbia Bryophyte Recovery Team and Garry Oak Ecosystems Recovery Team (BCBRT and GOERT). 2010. Management plan for twisted oak moss Syntrichia laevipila in British Columbia. Prepared for the BC Ministry of Environment, Victoria, BC. 16 pp. (Last accessed September 25, 2014)

Committee on the Status of Endangered Species in Canada (COSEWIC). 2004. COSEWIC assessment and status report on the twisted oak moss Syntrichia laevipila in Canada (PDF; 499KB). Committee on the Status of Endangered Wildlife in Canada, Ottawa. vi + 21 pp. (Last accessed September 25, 2014)

Committee on the Status of Endangered Wildlife in Canada (COSEWIC). 2011. Status Reports. Definitions and Abbreviations. Approved by COSEWIC in November 2011. (Last accessed September 25, 2014)

Gallego, M.T., M.J. Cano, and J. Guerra. 2004. A taxonomic study of Syntrichia laevipila (Pottiaceae, Musci) complex. Botanical Journal of the Linnean Society 145: 219–230.

IUCN Standards and Petitions Subcommittee. 2014. Guidelines for Using the IUCN Red List Categories and Criteria (PDF; 1.3MB). Version 11. Prepared by the Standards and Petitions Subcommittee. (Last accessed September 25, 2014)

McIntosh, T.T. and K. Sadler. 2011. Spring, 2011, addendum to results from a 2010 rare plant survey at the Canadian Forces Maritime Experimental Test Ranges (CFMETR), Vancouver Island. Report prepared for Natural Resources Canada, Canadian Forest Service.

Merrifield, K. 2000. Bryophytes on isolated Quercus garryana trunks in urban and agricultural settings in the Willamette Valley, Oregon. The Bryologist 103(4): 720–724.

Miles, W. 2002. Unpublished report summarizing results of 2001–2002 search for Tortula laevipila var. meridionalis (Contract # 02-225). BC Conservation Data Centre, Victoria, BC. 10 pp.

Mischler, B.D. 2007. Syntrichia. Pp. 618–627. In: Flora of North America Editorial Committee (eds.). Flora of North America north of Mexico, Vol. 27, Bryophytes: Mosses, part 1. Oxford University Press, New York, NY. 734 pp. (Last accessed September 25, 2014)

NatureServe. 2004. A habitat-based strategy for delimiting plant element occurrences: Guidance from the 2004 Working Group (PDF; 82.6KB). (Last accessed September 25, 2014)

NatureServe. 2013. NatureServe Explorer: An online encyclopedia of life. Version 7.1. NatureServe, Arlington, Virginia. [Web application] Tortula laevipila. (Last accessed September 25, 2014)

Parks Canada Agency. 2011. Management plan for Twisted Oak Moss (Syntrichia laevipila) in Canada (PDF; 499KB). Species at Risk Act Management Plan Series. Parks Canada. Agency. Ottawa. iii + 30 pp. (Last accessed September 25, 2014)

Tropicos. 2013. Tropicos, botanical information system at the Missouri Botanical Garden, St. Louis, Missouri. [Web application] Syntrichia laevipila. (Last accessed September 25, 2014)

University of British Columbia Herbarium (UBC). 2013. Bryophyte Database. Herbarium, Beaty Biodiversity Museum, University of British Columbia, Vancouver, BC. [Web application]. Syntrichia laevipila. (Last accessed September 25, 2014)

Author of SAS: G. Karen Golinski

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Technical Summary

Scientific Name:
Syntrichia laevipila
English Name:
Twisted Oak Moss
French Name:
Tortule à poils lisses
Range of occurrence in Canada:
British Columbia

Demographic Information

  • Generation time (usually average age of parents in the population; indicate if another method of estimating generation time indicated in the IUCN guidelines (2008) is being used).

    To date there have been no studies of population characteristics of Twisted Oak Moss.

    • Unknown
  • Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?

    There is no evidence to suggest that the number of mature individuals is declining except through habitat destruction such as the loss of the Langford occurrence to urban development.

    • Unknown
  • Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]

    • Unknown
  • [Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations]

    • Unknown
  • [Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations] (78-90 years).

    • Unknown
  • [Observed, estimated, inferred or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.

    • Unknown
  • Are the causes of the decline clearly reversible and understood and ceased?

    The only suspected loss of mature individuals occurred as a result of urban development which eliminated the host tree.

    • Not applicable
  • Are there extreme fluctuations in number of mature individuals?

    • No

Extent and Occupancy Information

  • Estimated extent of occurrence

    The discovery of two new occurrences outside the existing EO substantially increased its area.

    • 4600 km²
  • Index of area of occupancy (IAO)

    (Always report 2x2 grid value).

    The discovery of 24 new sites since 2004 substantially increased the IAO.

    • 112 km²
  • Is the population severely fragmented?

    Most sites where Twisted Oak Moss occurs in Canada have not been visited for > 10 years. Therefore the true extent of population fragmentation is unknown. However, based on known information, at least 50% of the total area of occupancy is in habitat patches that are very small and are separated from other habitat patches by long distances (IUCN 2014).

    • Unknown
  • Number of locations

    See Definitions and Abbreviations on COSEWIC website and IUCN 2014 for more information on this term.

    Based on threat of tree removal, and habitat alteration resulting from urban development

    • Unknown, but possibly > 90
  • Is there an observed continuing decline in extent of occurrence?

    • No
  • Is there an observed continuing decline in index of area of occupancy?

    • No
  • Is there an observed continuing decline in number of populations?

    • No
  • Is there an observed continuing decline in number of locations?

    See Definitions and Abbreviations on COSEWIC website and IUCN 2014 for more information on this term.

    • No
  • Is there an observed continuing decline in area, extent and/or quality of habitat?

    Based on the loss of one occurrence to urban development, and the continued urban expansion in SW British Columbia.

    • Maybe
  • Are there extreme fluctuations in number of populations?

    • No
  • Are there extreme fluctuations in number of locations?

    See Definitions and Abbreviations on COSEWIC website and IUCN 2014 for more information on this term.

    • No
  • Are there extreme fluctuations in extent of occurrence?

    • No
  • Are there extreme fluctuations in index of area of occupancy?

    The IAO has increased since 2004, but again, only two sites have been revisited since that time.

    • No

Number of Mature Individuals

  • Total SLE Population:

    See Table 1. Population details for most occurrences are vague, outdated, or non-existent.

    • Total: > 450?

Quantitative Analysis

  • Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years].

    • Not available

Threats (actual or imminent, to populations or habitats)

Threats to Twisted Oak Moss identified in previous reports (COSEWIC 2004, BCBRT and GOERT 2010, Parks Canada 2011) include:

  1. Direct removal of individual host trees (or branches),
  2. Loss of host trees as a result of habitat degradation,
  3. Lack of host tree recruitment, and
  4. Air pollution.

The threat of lack of host tree recruitment is slightly diminished by the discovery of Twisted Oak Moss on substrates and tree species other than Garry Oak (although this is not frequent).

Rescue Effect (immigration from outside Canada)

  • Status of outside population(s)?

    • Syntrichia laevipila (Tortula laevipila) is not ranked in any US states. Its global status is G3G4 (NatureServe 2013).
  • Is immigration known or possible?

    • Unknown
  • Would immigrants be adapted to survive in the SLE?

    • Possibly
  • Is there sufficient habitat for immigrants in the SLE?

    • Possibly
  • Is rescue from outside populations likely?

    • No

Data-Sensitive Species

  • Is this a data-sensitive species?
    • Yes

Permission was not granted to share data from one occurrence on Saltspring Island (EO ID 7856). Data from the Canadian Forces Maritime Experimental Test Ranges (CFMETR) at Nanoose Bay (EO ID 7895) cannot be shared with the BC Conservation Data Centre until a data-sharing agreement is established.

Status History

  • COSEWIC(2004): Special Concern

Criteria: “Met criterion for Threatened, D2, but designated Special Concern because of the high potential numbers of Garry Oak host.”

Reasons for Designation (2004): “This moss is a small species that occurs from British Columbia and Washington southward to California. The Canadian populations are at the northern limits of their range in western North America, and in Canada the species has a restricted distribution where it occurs in the area of south-eastern Vancouver Island and the Gulf Islands. The species is known from more than 25 sites where it is restricted to the bark of trees, in particular Garry oaks. This species is never dominant where it grows, nor is it frequent in large oak stands. Many of the known populations are in protected areas. The major threat to the species is the disappearance of mature Garry oaks, which would result in the extirpation of most populations of this species.”

Status and Reasons for Designation:

Status:
Special Concern
Alpha-numeric code:
not applicable
Status History:
Designated Special Concern in May 2004. Status re-examined and confirmed in November 2014
Reasons for designation:
This moss occurs from British Columbia and Washington southward to California. The Canadian populations, which are at the northern limits of the species’ range in western North America, occur only in the area of southeastern Vancouver Island and the Gulf Islands. The species is known from more than 90 sites where it is largely restricted to the bark of trees, especially Garry Oak. This species is never dominant where it grows, nor is it frequent in large oak stands. The major threat to the species is the removal of mature Garry Oak. Without land management practices that build and preserve Garry Oak populations, this threat would result in the extirpation of most populations of this species.

Applicability of Criteria

Criterion A (Decline in Total Number of Mature Individuals):
Not applicable. Data not sufficient to infer declines.
Criterion B (Small Distribution Range and Decline or Fluctuation):
Not applicable. Meets B1 (extent of occurrence estimated to be < 5000 km²) and B2 (index of area of occupancy estimated to be < 500 km²) criteria for Endangered, but there is no evidence for a decline in extent of occurrence, index of area of occupancy, area, extent and/or quality of habitat, number of locations or subpopulations, or number of mature individuals; the population is not severely fragmented and the number of locations is much higher than the thresholds.
Criterion C (Small and Declining Number of Mature Individuals):
Not applicable. Based on available information, the number of mature individuals is not declining.
Criterion D (Very Small or Restricted Population):
Not applicable. The number of mature individuals for this species likely exceeds 1000 and the number of locations is much greater than 5.
Criterion E(Quantitative Analysis):
Not applicable. No analysis has been done.

Additional Sources of Information:

Tracy Cornforth, CFB Esquimalt, BC

Marta Donovan, British Columbia Conservation Data Centre, BC Ministry of Environment, Victoria, BC

Judith Harpel, University of British Columbia Herbarium, Beatty Biodiversity Museum, Vancouver, BC

Steve Joya, University of British Columbia Herbarium, Beatty Biodiversity Museum, Vancouver, BC

Terry McIntosh, Vancouver, BC

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Table 1. Occurrences of Twisted Oak Moss in Canada. Asterisks (*) indicate occurrences and sub-occurrences (found within 1 km of other places where the species was found) discovered after the status assessment was published (COSEWIC 2004). “EO ID” refers to the unique identifier applied by the BC Conservation Data Centre. Data sources: COSEWIC 2004, BCBRT and GOERT 2010, Parks Canada 2011, Joya pers. comm. 2012, 2013, and BC Conservation Data Centre 2013. Note:  Sensitive data have been removed but can be made available upon request from the COSEWIC Secretariat.
No.Occurrence (EO ID)Sub-occur-anceDates observedPopulation sizeSubstrateLand tenureNew observations*; extirpated
1Nanoose (7895)1a-Sensitive data---
--1b*-Sensitive data---
--1c*-Sensitive data---
--1d*-Sensitive data---
--1e*-Sensitive data---
--1f*-Sensitive data---
2Nanoose (11219)*-2011No dataGarry OakPrivate (undeveloped)New
3Galiano Island (7421)-20028 small tuftsGarry OakRegional (CRD Park Reserve)-
4Duncan (7424)-2001No dataGarry OakNature Conservancy of Canada-
5Duncan (7896)-1978No dataGarry OakProvincial (Ecological Reserve)-
6Saltspring I. (7422)6a20025-20 clumpsGarry OakProvincial (Ecological Reserve)-
--6b2002No dataGarry OakProvincial (Ecological Reserve)-
--6c2002No dataGarry OakProvincial (Ecological Reserve)-
--6d2002No dataGarry OakProvincial (Ecological Reserve)-
--6e*2006Large patchGarry OakProvincial (Ecological Reserve)New
7Saltspring I. (7855)72001No data (2001, 2002), > 5 patches (2007)Garry OakProvincial (Park)-
8Saltspring I. (7856)*8-Sensitive data---
9North Saanich (7418)9a200215 tufts (2002), 5-20 clumps (2002)Garry OakRoadside / School-
--9b2002No dataGarry OakRoadside / School-
--9c2002No dataGarry OakRoadside / School-
10North Saanich (7419)1020025 to 6 tufts (2002),
< 5 clumps (2002)
Garry OakRoadside-
11Victoria (11168)*112010No dataGarry OakCollegeNew
12Saanich (7423)1220025-20 clumpsGarry OakMunicipal park-
13Saanich (7409)13a2001No dataGarry OakMunicipal park-
--13b2001No dataGarry OakMunicipal park-
--13c2001No dataGarry OakMunicipal park-
--13d2001No dataGarry OakMunicipal park-
--13e2001No dataGarry OakMunicipal park-
--13f20018 small tuftsGarry OakMunicipal park-
--13g2002No dataGarry OakMunicipal park-
--13h2002No dataGarry OakMunicipal park-
--13i200211 clumpsGarry OakMunicipal facility-
--13j2002No dataGarry OakMunicipal facility-
--13k2002No dataGarry OakMunicipal facility-
--13l200214 tuftsGarry OakMunicipal park-
--13m2002No dataGarry OakMunicipal park-
--13n2002No dataGarry OakMunicipal park-
--13o20035-20 clumpsGarry OakMunicipal park-
14Saanich (7412)142002No dataGarry OakUniversity-
15Saanich (7406)15a2001No data (2001), 11 clumps (2002)Garry OakMunicipal park-
--15b2002No dataGarry OakMunicipal park-
16Saanich (7411)16a200230 tufts (2002), > 20 clumps (2002)Garry OakRoadside-
--16b2002No dataGarry OakRoadside-
--16c2002No dataGarry OakRoadside-
--16d*20082-3 clumpsGarry OakPrivate (residential)New
17Oak Bay (7403)17a2001> 20 patches (2001)Garry OakRoadside-
--17b*2007> 20 patches (2007)Garry OakCollegeNew
18Oak Bay (7407)18a2001No data (2001), 13 clumps (2002), 5-20 clumps (2003)Garry OakMunicipal park-
--18b2001No dataGarry OakMunicipal park-
--18c2001No dataGarry OakMunicipal park-
--18d2001No dataGarry OakMunicipal park-
19Oak Bay (7404)19a2001No data (2001, 2002), > 20 clumps (2002)Garry OakMunicipal (library)-
--19b2001Large clump (2001), > 20 clumps (2002)Garry OakRoadside-
--19c2001~40 clumps (2001), < 25 clumps (2003)Garry OakPrivate (residential)-
--19d*2009No dataGarry OakRoadsideNew
--19e*2009No datamortar, stone wallRoadsideNew
--19f*2010No dataGarry OakMunicipal (public works yard)New
20Victoria (7425)-2003> 20 clumps (2003)Garry Oak, Bigleaf MapleCity parkNew
21Victoria (7415)21a2002> 20 clumps (2002)Garry OakCity park-
--21b2002No dataGarry OakCity park-
22Victoria (7410)22a2001> 10 clumps (2001)Garry OakMunicipal park-
--22a20025-20 clumps (2002)Garry OakMunicipal park-
--22b2001No data (2001)Garry OakMunicipal park-
--22c2001No data (2001)Garry OakMunicipal park-
--22d2001No data (2001)Garry OakMunicipal park-
--22e2002Several tufts (2002), > 20 clumps (2003)Garry OakPrivate (residential)-
--22f*2009No dataElmRoadsideNew
--22g*2009No dataGarry OakRoadsideNew
--22h*2009No dataGarry OakRoadsideNew
--22i*2009No dataElmRoadsideNew
--22j*2011No dataSweetgumRoadsideNew
--22k*2011No dataGarry OakRoadsideNew
23Victoria (7408)23a1930No data (1930, 1996, 2001), > 20 clumps (2002)Garry Oak, Norway MapleCity park-
--23b2001No dataGarry OakCity park-
--23c2001No dataGarry OakCity park-
--23d2001No dataGarry OakCity park-
--23e*2007No dataGarry OakCity parkNew
--23f*2009No dataNorway MapleCity parkNew
24Victoria (11208)*242010No dataSweetgumRoadsideNew
25Colwood (7414)25a2002> 20 tufts (2002)Garry OakMunicipal (recreation centre)-
--25b2002No dataGarry OakMunicipal (recreation centre)-
--25c2002No dataGarry OakMunicipal (recreation centre)-
26Esquimalt (7416)26a2002Several tufts (2002), > 20 clumps (2002)Garry OakSchool-
--26b2002No dataGarry OakSchool-
--26c2002No dataGarry OakMunicipal park-
--26d2002No dataGarry OakMunicipal park-
--26e2002No dataGarry OakMunicipal park-
--26f2002No dataGarry OakMunicipal park-
27Pedder Bay (7897)271976No dataGarry OakUnknown-
28Vancouver (11213)*282010No dataNorway MapleRoadsideNew
29Langford (7413)29200222 tufts (2002), > 20 clumps (2002)Garry OakRoadsideExtirpated

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Figure 1. The distribution of Twisted Oak Moss in Canada.
The distribution of Twisted Oak Moss in Canada
Long description for Figure 1

Map showing the distribution of the Twisted Oak Moss in Canada. The moss is currently known from 28 occurrences. Twenty-seven are located on southeastern Vancouver Island and the adjacent Gulf Islands of British Columbia. One is found in Vancouver.

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Glossary

Impact
The degree to which a species is observed, inferred, or suspected to be directly or indirectly threatened in the area of interest. The impact of each threat is based on Severity and Scope rating and considers only present and future threats. Threat impact reflects a reduction of a species population or decline/degradation of the area of an ecosystem. The median rate of population reduction or area decline for each combination of scope and severity corresponds to the following classes of threat impact: Very High (75% declines), High (40%), Medium (15%), and Low (3%). Unknown: used when impact cannot be determined (e.g., if values for either scope or severity are unknown); Not Calculated: impact not calculated as threat is outside the assessment timeframe (e.g., timing is insignificant/negligible or low as threat is only considered to be in the past); Negligible: when scope or severity is negligible; Not a Threat: when severity is scored as neutral or potential benefit.
Scope
Proportion of the species that can reasonably be expected to be affected by the threat within 10 years. Usually measured as a proportion of the species’ population in the area of interest. (Pervasive = 71–100%; Large = 31–70%; Restricted = 11–30%; Small = 1–10%; Negligible < 1%).
Severity
Within the scope, the level of damage to the species from the threat that can reasonably be expected to be affected by the threat within a 10-year or three-generation timeframe. Usually measured as the degree of reduction of the species’ population. (Extreme = 71–100%; Serious = 31–70%; Moderate = 11–30%; Slight = 1–10%; Negligible < 1%; Neutral or Potential Benefit > 0%).
Timing
High = continuing; Moderate = only in the future (could happen in the short term [< 10 years or 3 generations]) or now suspended (could come back in the short term); Low = only in the future (could happen in the long term) or now suspended (could come back in the long term); Insignificant/Negligible = only in the past and unlikely to return, or no direct effect but limiting.

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COSEWIC History

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.

COSEWIC Mandate

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.

COSEWIC Membership

COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non-government science members and the co-chairs of the species specialist subcommittees and the Aboriginal Traditional Knowledge subcommittee. The Committee meets to consider status reports on candidate species.

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Definitions (2014)

Wildlife Species
A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.
Extinct (X)
A wildlife species that no longer exists.
Extirpated (XT)
A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.
Endangered (E)
A wildlife species facing imminent extirpation or extinction.
Threatened (T)
A wildlife species likely to become endangered if limiting factors are not reversed.
Special Concern (SC)
(Note: Formerly described as “Vulnerable” from 1990 to 1999, or “Rare” prior to 1990.)
A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.
Not at Risk (NAR)
(Note: Formerly described as “Not In Any Category”, or “No Designation Required.”)
A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.
Data Deficient (DD)
(Note: Formerly described as “Indeterminate” from 1994 to 1999 or “ISIBD” [insufficient scientific information on which to base a designation] prior to 1994. Definition of the [DD] category revised in 2006.)
A category that applies when the available information is insufficient (a) to resolve a species’ eligibility for assessment or (b) to permit an assessment of the species’ risk of extinction.

The Canadian Wildlife Service, Environment Canada, provides full administrative and financial support to the COSEWIC Secretariat.

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