Detection and Control Measures for the Invasive Marsh Thistle (Cirsium palustre)

Eamonn Hinchey and Donna Vogler SUNY College at Oneonta November 19, 2011 European Marsh Thistle Cirsium palustre

• Endemic to British Isles • Invaded European continent • From Canada to Upper Peninsula Michigan in 1980’s • Monocarpic biennial – Flowers only once then dies

Other common members of Cirsium

Cirsium vulgare Cirsium arvense

Monocarpic biennial Perennial Why Do We Care?

Shade tolerant

Can impact any disturbed area including: “Like Purple Loosestrife, with spines” Tony Reznick.

• Wetlands •Pastures • Road Sides • Power Lines Original Goals

• Map and identify the leading edge of current C. palustre populations in NYS. – Remove small easily accessible fringe populations on site. • Select multiple high-density populations to test eradication methods. • Implement early detection rapid response measures facilitated by citizen science. Previously reported in 1994 in Madison Co Persists in Madison Co. but not at original USGS site Discovered in Otsego Co. in 2005 in a Ducks Unlimited constructed wetland on the Greenwoods Conservancy iMapInvasives.org iMapInvasives.org iMapInvasives.org Future Mapping goals • Continue to assess population extent (Dispersal Rate) • Soil map overlays • Contact landowners and follow-up with mailings (Employing NRCS help)

Removal of 28 plants along a hillside seep in Chenango Co.

What is the optimum cutting protocol?

• 4 treatments: – June cut (A) – June + August cut (B) – August cut (C) – Control (D)

• Assessed ability to re-bolt – June Aug – 2011 2012

Eamonn measures plant height before treatment. • Rosette Study to test Cut plants dried to determine above-ground biomass. bienniality

After cutting we bagged them

• SUNY Oneonta Biological Field Station interns helped collect and weigh plants throughout the summer. Some populations bigger and taller than others.

Marsh Thistle = 2.1m Me = 1.9m Some had more flowers than others Average June Height vs. Average August Height 1.6

1.4

1.2

1

0.8 Avg June Height Avg August Height 0.6 Height (m)

0.4

0.2

0 Bullfrog Goldfinch Redwing Blackbird Beaver Pond Kraham Location June Height as a Percentage of Final 100

90

80

70

60

50

40

30

20

10

0 Bullfrog Goldfinch Redwing Blackbird Beaver Pond Kraham

Average of all five = 87% Caterpillar damage • Genetics undergraduates studied the CO1 gene • Apamea devastator, a glassy cutworm in the Noctuidae family. Potential for Biocontrol…

Percent of Population with Frass

60

50

40

30 Percent 20

10

0 Bullfrog Goldfinch Redwing Blackbird Beaver Pond Kraham

Location Average Height of Plants with Frass vs. Without Frass

1.4 1.2

1

0.8 With Frass 0.6 Without Frass 0.4 Height (m) 0.2 0 Bullfrog Goldfinch Redwing Beaver Pond Blackbird Location Average Mass of Plants With Frass vs. Without Frass

20 18 16 14 12 With Frass 10 Without Frass 8 Mass (g) 6 4 2 0 Bullfrog Goldfinch Redwing Beaver Pond Blackbird Location One day on the way to Bear Swamp Conservancy… Confused by what looks like a C. palustre x arvense hybrid population in Madison Co. After some investigation….

• We found multiple studies investigating the hybridization potential of Cirsium. • Hybrids are so common in Europe because the many different species have overlapping flower periods and overlapping habitat.

So does this mean that we now have enough invasive thistles for hybridization?

What are the implications? Determining hybrid potential

Canada thistle or Bull Thistle

Experiment A: Pollinator exclusion survey to try and create hybrids

Experiment B: Genetic study to determine hybridization using molecular markers

Experiment C: Morphological analysis followed by PCA to determine intermediacy Possible hybrid Next year • Interns at BFS will continue to control peripheral populations (EDRR)

• Determine Results of different cutting protocols

• Demographic study continues. – Age class distribution. – Determine if facultative biennial.

• Analysis of potential hybrids • Continue to analyze Apamea’s potential as biocontrol.

Pursue the “Off with their Heads” campaign employing landowner mailings and citizen science Benefits of Early Detection Rapid Response

• Minimal funding required. Undergraduate/Graduate students, Small county/state level agencies , Concerned Citizens.

• Strong landowner approval

• Potential to monitor or even control other invasive plants along the way (iMap) Thank You