Candidate Species at Risk Evaluation Report for Showy Goldenrod (Solidago speciosa)

Committee on the Status of Species at Risk in Ontario (COSSARO)
Assessed by COSSARO as Threatened/Endangered
February 2011

Part 1: COSSARO Candidate Species at Risk evaluation form

Current designations:

GRANK

Solidago speciosa - G5
Solidago speciosa spp. speciosa – G5TNR
Solidago speciosa var. rigidiuscula – G4T4

NRANK Canada

Solidago speciosa – N1
Solidago speciosa spp. speciosa – NNR
Solidago speciosa var. rigidiuscula – N1

COSEWIC

Great Lakes Plains population – Endangered (November 2010)
Boreal population – Threatened (November 2010)

SARA

Showy Goldenrod – Endangered, Schedule 1
Showy Goldenrod (Great Lakes Plains population) – No status, No schedule
Showy Goldenrod (Boreal population) – No status, No schedule

General Status Canada

Showy Goldenrod – At Risk (2005)

ESA 2007

Showy Goldenrod – Endangered

SRANK

Solidago speciosa – S1
Solidago speciosa spp. speciosa – S1
Solidago speciosa var. rigidiuscula – S1

General Status Ontario

Showy Goldenrod – At Risk (2005)

Distribution and status outside Ontario:

The entire species has a range across much of eastern North America, with an outlying area in Montana, Wyoming and Colorado. It is fairly common through much of the range (COSEWIC, 2000). Much less than 1% of the total range and the total population is in Ontario.

Eligibility criteria

Native status

Yes. There are historic records from southern Ontario. There is no reason to doubt that it is native.

Taxonomic distinctness

Yes. Showy Goldenrod is a distinct species. Several varieties occur across the range. In Ontario, the southern populations have been identified as Solidago speciosa var. rigidiuscula. The variety of the northern population has not been determined.

Designatable units

There are two designatable units (DUs) in Ontario, a Great Lakes Plains DU and a Boreal DU in Northern Ontario (COSEWIC 2010). Both Great Lakes Plains populations are on Walpole Island First Nation (WIFN). The Boreal Population DU is near Kenora in northwestern Ontario. The two DUs are separated by about 1,200 km and occur in different ecological areas as recognized by COSEWIC. Plants from the two DUs also differ morphologically suggesting they may belong to different varieties and may be genetically distinct, although this has not yet been investigated.

Priority-setting criteria

Recent Arrival

No. The species is not a new arrival in Ontario. There are historical records from southern Ontario.

Non-resident

No. The species is clearly native to Ontario.

Great Lakes Plains DU

Primary criteria (rarity and declines)

1. Global rank

Not in any category. The G-Rank is G5 (G4 for Solidago speciosa var. rigidiuscula).

2. Global decline

Not in any category. There is no evidence for a substantial global decline. The species is not tracked in most of the jurisdictions where it occurs.

3. Northeastern North America ranks

Not in any category. Showy Goldenrod in occurs in 20 of 28 Northeastern North American jurisdictions, but is ranked in only 8 (40%) (Appendix 1). It has a rank of S1, S2, SH or SX in only two jurisdictions (S1 in Ontario and S2 in Maryland), 25% of the jurisdictions where it is ranked.

4. Northeastern North America decline

Not in any category. There are no data to document a North American decline. The species is common (and not tracked) over most of its range.

5. Ontario occurrences

EN. There are only two extant occurrences, both on Walpole Island First Nation.

6. Ontario decline

TH. The Great Lakes Plains DU has 2 extant populations and a recent population decline of about 38% based on censuses in 2003 and 2008. A WIFN population composed of a single plant was last recorded in 1998 and has since been extirpated. A large historical (1910) population has also disappeared on WIFN. A record from Perth County is presumed extirpated because the location has been developed. Assuming the existing 2 populations have been in existence for some time, there has been a loss of 50% (2 of 4) of documented Ontario sites (COSEWIC, 2010).

7. Ontario’s conservation responsibility

Not in any category. This DU represents <1% of the global range and the global population of this species (COSEWIC 2010).

Secondary criteria (threats and vulnerability)

1. Population sustainability

Not in any category. Most plants on WIFN are infested with the larvae of an unidentified species of Coleophora moth that destroy up to 85% of seeds in some populations (Mammoliti, 2006). The overall effects on recruitment are unknown.

2. Lack of Regulatory Protection for Exploited Wild Populations

Not in any category. There is no known exploitation of this species.

3. Direct threats

TH. Loss of prairie and savanna habitat where this species grows is the greatest threat facing this species on WIFN. Historically conversion to agriculture as destroyed many plants. Plants have has been lost to house building and cemetery expansion in the last 10 years. A population of one plant was destroyed by mowing. Proximity to housing has led to decreased fire frequency and growing in of trees and shrubs. Phragmites stands are expanding very close to plants at one population (Bowles, 2005)

Coleophora moth larvae destroy up to 85% of seeds in some populations.

4. Specialized life history or habitat-use characteristics

EN. This plant is a perennial that reproduces by seed. In southern Ontario it is restricted to tallgrass prairie and savanna habitats that are critically imperiled in Ontario and require fire for their maintenance.

COSSARO criteria met (primary/secondary)

Great Lakes Plains DU:

  • Endangered – [1/1]
  • Threatened – [1/1]
  • Special concern – [0/0]

Recommended Status: Endangered.

Boreal DU

Primary criteria (rarity and declines)

1. Global rank

Not in any category. The G-Rank for the species is G5, but the Boreal DU does not have an assigned G-Rank.

2. Global decline

Not in any category. There is no evidence for a substantial global decline. The species is not tracked in most of the jurisdictions where it occurs.

3. Northeastern North America ranks

Not in any category. Showy Goldenrod in occurs in 20 of 28 Northeastern North American jurisdictions, but is ranked in only 8 (40%) of them (Appendix 1). It has a rank of S1, S2, SH or SX in only two jurisdictions (S1 in Ontario and S2 in Maryland), 25% of the jurisdictions where it is ranked.

4. Northeastern North America decline

Not in any category. There are no data to document a North American decline. The species is common (and not tracked) over most of its range.

5. Ontario occurrences

There is one population near Kenora.

6. Ontario decline

Not in any category. The Boreal DU is a recent discovery (2007) and there are no data on population trends.

7. Ontario’s conservation responsibility

Not in any category. The DU represents <1% of the global range and the global population of this species.

Secondary criteria (threats and vulnerability)

1. Population sustainability

Not in any category. There are no data on population sustainability.

2. Lack of Regulatory Protection for Exploited Wild Populations

Not in any category. There is no known exploitation of this species.

3. Direct threats

Not in any category. The population is on Crown land, and a potential threat from development has probably been averted because development has been denied partly because of the presence of the plant. No other threats are known.

4. Specialized life history or habitat-use characteristics

This plant is a perennial that reproduces by seed. The plants grow along a steep rocky south-facing slope above a river shoreline. This is a habitat that often supports Dry Bur Oak Savannah (S3), but the site doesn't have any Bur Oak. It’s on a relatively open, grassy community dominated by Stipa spartea, and resembles a Dry Tallgrass Prairie, which is S1. This habitat type is unusual in the area (Bakowsky, pers. comm.).

COSSARO criteria met (primary/secondary)

Boreal DU:

  • Endangered – [1/0]
  • Threatened – [0/1]
  • Special Concern – [0/0]

Recommended Status: Threatened.

Summary

Showy Goldenrod (Solidago speciosa), a perennial, herbaceous plant, occurs as two DUs in Ontario, the Great Plains DU is Endangered, the Boreal DU is Threatened. The Great Lakes Plains DU has two populations of about 670 and 125 individuals respectively restricted to tallgrass prairie and savanna habitats. One of these populations had declined an estimated 38% between 2003 and 2008. Threats include habitat loss due to house building, cemetery expansion, invasive species and encroachment of woody species due to lack of fire. Furthermore, the larvae of an unidentified Coleophora moth has been eating the seeds of this plant. Declines in one population and threats to both account for the listing as Endangered.

The Boreal DU consists of a single, recently discovered population of about 1110 mature individuals. There is no information on decline in the number of mature individuals or quality of habitat of this population and no direct human threats have been documented. The single population accounts for the listing as Threatened.

Information sources

Bakowsky, W. 2011. Personal Communication. E-mail to M.J. Oldham, 16 February 2011.

Bowles, J.M. 2005. Recovery Strategy for the Showy Goldenrod (Solidago speciosa) in Canada [Proposed]. Species at Risk Act. 14 pp.

COSEWIC 2000. COSEWIC assessment and status report on the Showy Goldenrod Solidago speciosa var. rigidiuscula in Canada. Committee on the Status of Endangered Wildlife in Canada, Ottawa. vi + 14 pp.

COSEWIC 2010. Update COSEWIC Status Report on Showy Goldenrod (Solidago speciosa) in Canada. 6 month Interim Report. Committee on the Status of Endangered Wildlife in Canada. xv + 21 pp.

COSEWIC 2011. Database of wildlife species assessed by COSEWIC. [http://www.cosepac.gc.ca/eng/sct1/searchform_e.cfm]. [link inactive] Accessed January 2011.

Mammoliti, P. 2006. Studies in seed predation of Endangered Showy Goldenrod (Solidago speciosa) on Walpole Island First Nation. Unpublished Honours Thesis, Department of Biology, University of Western Ontario. 34 pp.

MNR, 2011. Ministry of Natural Resources. Species at Risk Website. Accessed January 2011.

NatureServe 2011. NatureServe Explorer: an Online Encylopedia of Life. [http://www.natureserve.org/explorer/]. Accessed January 2011.

Species at Risk Public Registry, 2011. Accessed January 2011.

Walpole Island Heritage Center, 2008. Species at Risk database. Internal information.

Wild Species, 2005. General Status Search Tool. [http://www.wildspecies.ca/wildspecies2005/search.cfm?lang=e&sec=9]. [link inactive] Accessed January 2011.

Appendix 1 – Showy Goldenrod

Northeastern North America rank, status and decline
(NatureServe 2011)

LocationNorth America rank

CT

SNR

DE

Not present

IL

SNR

IN

SNR

IA

S4

KY

S4?

LB

Not present

MA

SNR

MB

Not present

MD

S2

ME

Not present

MI

SNR

MN

SNR

NB

Not present

NF

Not present

NH

SNR

NJ

SNR

NS

Not present

NY

SNR

OH

SNR

ON

S1

PA

S3

PE

Not present

QC

Not present

RI

SNR

VA

S4

VT

S4

WI

SNR

WV

S4

Occurs as a native species in 20 of 29 northeastern jurisdictions Srank or equivalent information available for 8 of 20 jurisdictions = 40% S1, S2, SH, or SX in 2 of 8 = 25%

Part 2: Ontario evaluation using COSEWIC criteria

Great lakes Plains DU:

Regional (Great Lakes Plains DU) COSEWIC Criteria Assessment

Criterion A – Declining population

EN (A2, a,c,e). There was an estimated 38% decline in the number of mature individuals between 2003 and 2008 censuses. The quality of habitat is declining due to lack of fire and encroachment by woody species. Phragmites threatens to invade one site. Most seeds are destroyed by a moth larva.

Criterion B – Small distribution and decline or fluctuation

EN (B1a,b(iii,v) + B2a,b(iii,v)). EO is 2.2 km2 based on a convex polygon drawn around known sites. IAO is 8 km2. There are only 2 extant populations. Area and quality of habitat are declining and the number of mature individuals has declined.

Criterion C – Small population size and decline

TH (C2, a(i)). There are estimated <795 mature individuals. Both populations combined contain >250, but <1000 mature individuals.

Criterion D – Very small or restricted

TH (D1, D2). The total estimated population is <1000 mature individuals. There are 2 known locations with an IAO of 8 km2 and there are continuing threats that are likely to reduce the populations.

Criterion E – Quantitative analysis

Insufficient Information. There are insufficient numerical data available to develop a PVA.

Rescue effect

No. There is very unlikely to be rescue from populations in Michigan, because of the large distance and intervening unsuitable habitat. Habitat is Canada is very rare and declining.

Boreal DU:

Regional (Boreal DU) COSEWIC criteria assessment

Criterion A – Declining population

Insufficient Information. There is no demonstrated population decline.

Criterion B – Small distribution and decline or fluctuation

Insufficient Information. EO is <4 km2 as a nominal value based on minimum IAO. IAO is 4 km2. There is only one population, but there is insufficient evidence to show if the habitat or number of individuals is declining.

Criterion C – Small population size and decline

Insufficient Information. There are estimated 1100 mature individuals in one population, but there is no documented decline.

Criterion D – Very small or restricted

?TH (D1). There is one known location with an IAO of 4 km2, The number of mature individuals is estimated at 1100, which is slightly above the threshold for threatened. This may be an over-estimate if some plants are connected underground.

Criterion E – Quantitative analysis

Insufficient information. There are no trend data available with which to perfrom a PVA.

Rescue effect

No. Rescue is highly unlikely because the nearest populations of the species are a great distance away with unsuitable intervening habitat. There may be no other populations in this DU. Suitable habitat in Canada is very limited.