Round-leaved greenbrier (Smilax rotundifolia) COSEWIC assessment and status report: chapter 12

Technical Summary - Atlantic population

Smilax rotundifolia

Round-leaved Greenbrier: Atlantic population – Smilax à feuilles rondes : Population de l’Atlantique

Range of Occurrence in Canada:

southwestern Nova Scotia

Extent and Area Information

Extent of occurrence (EO) (km²) :

<5000 km²

Specify trend in EO :

stable

Are there extreme fluctuations in EO?

No

Area of occupancy (AO) (km²)

>50 km² based on > 50 populations and using a 1 km² grid or a 2x2 km grid

Specify trend in AO :

stable

Are there extreme fluctuations in AO?

No

Number of known or inferred current locations :

Likely > 50

Specify trend in # :

Stable

Are there extreme fluctuations in number of locations?

No

Specify trend in area, extent or quality of habitat :

Uncertain but likely stable

Population Information

Generation time (average age of parents in the population) :

Difficult to assess: clonal – Average age of well-developed vines and clones could readily be several decades or older; age to reproduction could be only a few years.

Number of mature individuals :

3,000-10,000 individuals (crowns) but number of genetically discrete plants (clones) unknown

Total population trend:

Stable

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

-

Are there extreme fluctuations in number of mature individuals?

No

Is the total population severely fragmented?

Uncertain but disjunct from US populations

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:

No specific data are available since the populations are not tracked provincially

Threats (actual or imminent threats to populations or habitats)

Limited and related mainly to cottage and residential developments.

Rescue Effect (immigration from an outside source)

Status of outside population(s)?

USA: Common

Is immigration known or possible?

Unknown, but likely not possible

Would immigrants be adapted to survive in Canada?

Yes

Is there sufficient habitat for immigrants in Canada?

Yes

Is rescue from outside populations likely?

No

Quantitative Analysis

[provide details on calculation, source(s) of data, models, etc] : None available.

Current Status

  • Secure in Nova Scotia (General Status of Wild Species 2005)
  • COSEWIC: Not At Risk (2007)

Status and Reasons for Designation

Status: Not at Risk

Alpha-numeric code: Not applicable

Reasons for Designation: The species is known from at least 50 sites in southern Nova Scotia where there are estimated to be at least 3,000 to 10,000 individuals (crowns). The actual number of mature individuals for this clonal species is, however, unknown. No declines have been documented and threats are limited.

Applicability of Criteria

  • Criterion A: (Declining Total Population): Not applicable. No declines documented.
  • Criterion B: (Small Distribution, and Decline or Fluctuation): Not applicable. EO and AO are both below maximum levels allowed for either Endangered or Threatened but there are > 50 populations, no continuing decline has been documented, and the species does not undergo extreme fluctuations.
  • Criterion C: (Small Total Population Size and Decline): Not applicable. The actual number of mature individuals is unknown due to the clonal nature of the species and no continuing decline has been documented.
  • Criterion D: (Very Small Population or Restricted Distribution): Not applicable. Total number of mature individuals is unknown but likely > 1000 and there are >50 locations and the AO is much greater than 20 km².
  • Criterion E: (Quantitative Analysis): None available

Page details

Date modified: