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COSEWIC Assessment and Status Report on the Baikal Sedge in Canada

Technical Summary

Carex sabulosa

Baikal sedge
carex des sables

Range of Occurrence in Canada: Yukon Territory


Extent and Area Information

Extent of occurrence (EO)(km2)
(Area encompassed within a polygon including the 3 extant dune systems)

ca. 200 km2


Specify trend in EO

Stable


Are there extreme fluctuations in EO?

No


Area of occupancy (AO)(km2)
(Sum of the extant dune systems supporting the 5 populations)

ca 0.74 km2


Specify trend in AO

Decline (2-3%)


Are there extreme fluctuations in AO?

No


Number of known or inferred current locations

3 extant with 5 populations


Specify trend in #

Stable


Are there extreme fluctuations in number of locations?

No


Specify trend in area, extent or quality of habitat

Decline



Population Information

Generation time (average age of parents in the population)

Several years


Number of mature individuals

3.5-5 million ramets (uncertain as to how many separate plants this represents due to extensive rhizomatous growth)


Total population trend

Declining


% decline over the last/next 10 years or 3 generations

1-2% over 30-40 years


Are there extreme fluctuations in number of mature individuals?

No


Is the total population severely fragmented?

No


Specify trend in number of populations

Stable


Are there extreme fluctuations in number of populations?

No


List populations with number of mature individuals in each:

  1. 3-4 million/ca. 38.3 ha (Kaskawulsh/Dezadeash Rivers
  2. 168-294 000/ca. 8.4 ha (Takhini River, south)
  3. 240-288 000/ca. 9.6 ha (Takhini River, north)
  4. 131-196 000/ca. 13.1 ha (Carcross-Bennett Lake)
  5. 38-58 000/ca. 4.8 ha (Carcross-Klondike Highway)


Threats (actual or imminent threats to populations or habitats)

  • imminent development of a major resort at Carcross, together with a planned regular rail service to Carcross for 2006, poses a significant threat from increased recreational use of the dunes in the area
  • future changes due to climate changes may pose a real threat in northern mountains and the arctic (Kluane Glaciers are retreating dramatically)
  • future changes due to climate changes may pose a real threat in northern mountains and the arctic (Kluane Glaciers are retreating dramatically)


Rescue Effect (immigration from an outside source)

Status of outside population(s)?

USA: Critically imperiled in Alaska; Asia?



Is immigration known or possible?

Unlikely


Would immigrants be adapted to survive in Canada?

Yes


Is there sufficient habitat for immigrants in Canada?

No


Is rescue from outside populations likely?

No



Quantitative Analysis

[provide details on calculation, source(s) of data, models, etc]

N/A


Current Status

COSEWIC: Threatened (May 2005)


Status and Reasons for Designation

Status: Threatened

Alpha-numeric code:  Met criterion for Endangered B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v), but designated Threatened because there are large numbers in protected areas and because of the low level of threats within these localities. Criteria met for Threatened B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v); D2. 

Reasons for Designation: A geographically restricted species of three sand dune areas that serve as habitat for five populations. These consist of several million shoots produced mainly through asexual reproduction. The species has been impacted by declines in population size, area, quality of its habitat and on-going impacts from the recreational use of all-terrain vehicles: at Carcross and Bennett Lake. Such activity and much increased tourist visitations at the Carcross dune systems may result in increased impacts on the habitat with the development of a major resort facility at this location by 2006. If the Alsek River is dammed again by the advance of the Lowell Glacier, as has occurred in recent past, the large population at the confluence of the Dezadeash and Kaskawulsh Rivers could be at risk.


Applicability of Criteria

Criterion A (Declining Total Population):
Not met due to very limited decline.

Criterion B (Small Distribution, and Decline or Fluctuation):
Meets Endangered B1ab(ii-v)+2ab(ii-v) with a very small extent of occurrence (ca. 200 km²) and area of occupancy (<1 km2); declines are also evident in area of occupancy, quality of habitat, and number of mature plants resulting especially from recreational use of the sand dune habitat. However, in spite of the potential impact of a major resort facility at Carcross, the largest population is within Kluane National Park Reserve (Kaskawulsh/Dezadeash River population), comprising perhaps 80% of the total population. Also, the two Takhini River populations are only accessible by canoe with no or minimal human disturbance at these sites at present and will be protected within the proposed Kusawa Territorial Park. The past overall decline in total habitat has only been in the order of 2-3%.

Criterion C (Small Total Population Size and Decline):
Not met due to large population size.

Criterion D (Very Small Population or Restricted Distribution):
Meets threatened D2 based on the presence of only 5 populations and on-going and imminently increased threat from recreational activities, particularly at the Carcross dunes.

Criterion E (Quantitative Analysis):
None available.