Archive for the ‘Invasive Species’ category

Carline Thistle Seen in Otsego County

September 6, 2012

Until now, the Carline thistle (Carlina vulgaris) has only been recorded for Cortland and Tompkins County, New York (see NYFA Atlas). Recently it was seen naturalized in fields in Otsego County by NYFA board member and botanist Connie Tedesco. The USDA Plants database only has it occurring in New York and New Jersey.  It is a Eurasian species that was introduced in the mid-1900s to New York.

The information at the NY state museum for this species shows it was collected for the first time in Cortland County in August, 1948 by R.T. Clausen “SE of Dryden Lake, Harford.” It was seen again south of Harford Mills in Cortland County by Stanley Smith Sept. 17, 1955. This is on the border of Tioga County. Arthur Cronquist reported it to the museum as common and spreading in Ithaca in 1983.

Is this a new invasive species on the move? If you see this plant naturalizing in your area please leave a comment at this blog entry.  Thanks. – Steve Young

Plants from an Otsego County field. Photos Connie Tedesco.


Check Native Impatiens/Touch-me-not/jewelweed for Downy Mildew

June 7, 2012

Recently there have been outbreaks in the Northeast of a potentially devastating disease on garden impatiens (Impatiens walleriana), a downy mildew caused by Plasmopara obducens.  Cornell Cooperative Extension is looking for help in determining whether this downy mildew is currently affecting native jewelweeds. The New Guinea impatiens (I. hawkeri) does not seem to be affected.  For more info on the disease CLICK HERE.  For more information on what to look for CLICK HERE. If you find what you think is the mildew, collect a sample of the leaves in a clean plastic bag with a moist paper towel, seal it, and mail to:

Margaret Daughtry, Cornell University-LIHREC, 3059 Sound Ave., Riverhead, NY 11901.

This shows what happens to garden impatiens with the mildew.

NY Botanical Garden Seminar, May 4: Phenotypic Plasticity and Plant Invasions.

April 30, 2012

“Examining the role of natural selection and phenotypic plasticity in plant invasions: a study of invasive Japanese knotweed (Fallopia japonica) and native woodland knotweed (Persicaria virginiana)”

Kelly O’Donnell, PhD., Postdoctoral Fellow
Columbia University

Friday, May 4, 2011
11am-12 noon
Watson 302
Refreshments at 10:45

Kelly O’Donnell

Dissertation Abstract

Determining the role of natural selection in plant invasions

The ecological and evolutionary study of plant invasion processes is of exceeding importance in today’s changing environment. However, few studies have addressed the impact of natural selection on invasive plant species. While scientists have been able to detect selection in natural populations, most studies are not replicated in space or time leading to unreliable statistical estimates and tentative causal analyses. My objective is to further our knowledge of selection dynamics in the wild by working in the area of invasion biology through studies that combine both field and controlled settings. Biological invasions may be thought of as natural evolutionary experiments that scientists can use to study the effects of possibly novel and intense selection pressures on species that are in the process of aggressively expanding their range. It has been suggested that plant invasion affords us the ability to better assess the speed and predictability of local adaptation by natural selection, and that there are at least two mechanisms by which species can become invasive: through rapid local adaptation and/or through augmented phenotypic plasticity. It remains to be seen if either or both of these statements are generally true, as they have been rarely tested in the field. I have conducted a multi-year selection analysis on field populations of invasive Japanese knotweed (Fallopia japonica) and a native relative, woodland knotweed (Persicaria virginiana) and found strong, but temporally variable, natural selection. I then assessed the level of local adaptation in Japanese knotweed and compared it to woodland knotweed via a reciprocal transplant experiment. Despite the strong selection pressure (but perhaps because of the variability), there was little evidence of local adaptation in either species. Finally, I examined both species to measure their plasticity for traits relating to light acquisition in a common garden experiment. Both species had plastic trait responses to shade, but they followed different plasticity strategies. Woodland knotweed followed a “jack-of-all-trades” approach; it was able to thrive under either light treatment. Japanese knotweed seemed to use the opportunistic “master-of-some” strategy; its trait plasticity allowed it to take advantage of a better quality environment. Overall, there was no clear distinction between the native and invasive species studied. Both experience strong selection, but do not seem to locally adapt to it. Both possess trait plasticity that allows them to thrive in different light conditions, although the strategy is different.

Cornell Announces Emerald Ash Borer NYS First Detector Training

April 23, 2012

Want to help in the fight with Emerald Ash Borer? We’re looking for First Detectors who want to:

  • Become a local expert who can answer EAB biology and management questions.
  • Aid in the community preparedness planning process
  • Engage others as volunteers to monitor for EAB, conduct street tree inventories, collect ash seed and educate about the issues surrounding Emerald Ash Borer

These training sessions will go over in-depth details of EAB biology, signs and symptoms, hosts, control and management, reporting, and resources through presentations and hands-on field activities at near-by EAB infested locations. Materials have been created by Cornell University and the Northeast Plant Diagnostic Network. These workshops are supported by a Northeastern IPM Center- IPM Partnership Grant.

Who should take this training?

Anyone that is concerned about EAB. But especially if you are a: Cornell Cooperative Extension employee; Cornell Cooperative Extension volunteer (Master Gardener, Master Forest Owner, Master Naturalist, 4-H Leader); PRISM partner (Partnerships for Regional Invasive Species Management); SWCD or NRCS employee; Arborist; Forester; Logger; Landscaper; Planner; Environmental Educator; Municipal Employee; or a  Community Volunteer

First Detectors can give back.

There is huge public demand for answers on what to do about EAB. As a trained EAB First Detector, you’ll have those answers. We hope that you will be able to help the greater community by sharing your EAB knowledge, participating in community preparedness activities, or monitoring for EAB.

Workshop Details

May 14, 2012. 1-5 pm at the Agroforestry Resource Center (CCE Columbia and Greene) 6055 Route 23, Acra, NY 12405.

May 18, 2012. 1-5 pm at Reinstein Woods Nature Preserve and Environmental Education Center (Erie County), 93 Honorine Dr. Depew, NY 14043.

May 29, 2012. 1-5 pm at Cornell Cooperative Extension of Monroe County, 249 Highland Avenue
Rochester, NY 14620.

All sessions are FREE, but registration is required. Please register at

These courses are eligible for: 2.5 ISA CEUs, 0.5 NYLT TLC elective credits, and 4 CNLP credits.

NYS DEC Pesticide & SAF CF credits have been applied for. Please stay tuned to the Events section of for updates.

Questions, email Rebecca at or call 607-334-5841 x 16

J Rebecca Hargrave

Horticulture and Natural Resources Extension Educator, Cornell Cooperative Extension of Chenango County

99 N Broad St, Norwich, NY 13815  phone: 607-334-5841 x 16    fax: 607-336-6961

State Champion Asian Bittersweet?

February 10, 2012

Tim Wenskus from New York City Department of Parks holds the trunk of an Asian bittersweet vine recently cut by Mike Feder in Highland Park on the border of Queens and Brooklyn. This is the largest diameter bittersweet that Tim had ever seen.  Has anyone seen a bigger one?

Guide to Identifying Viburnum Species

February 7, 2012

Cornell University has a guide to identifying native and exotic Viburnum species as part of their citizen science project on Viburnum leaf beetles. To access the guide CLICK HERE. There is also good information on the beetle itself and a list of viburnums with their susceptibility ranking that you can ACCESS HERE. We hope the Viburnums can somehow survive the beetles in the long run.

Information on New Hydrilla Infestation in Cayuga Lake

October 7, 2011

The invasive aquatic plant Hydrilla has been found in the inlet to Cayuga Lake in Ithaca.  This may have a big impact on the lake and its native aquatic flora in the future.  For a 40 minute video about the infestation CLICK HERE.

iMap Invasives Program Now Has a Facebook Page

September 13, 2011

Get the latest information about what invasives are being mapped, where new invasives are turning up, announcements and more.  CLICK HERE to see the page and become more involved in helping iMap locate invasive species.

Screenshot of the iMap Facebook page

Our Disappearing Flora and Deer

August 1, 2011

The deleterious effect of too many deer on native vegetation has been known for some decades now and many studies have been done in New York. Unfortunately we are still unable to change policy and practices to reduce the deer herd to levels where our vegetation can recover.  Two recent articles have come out demonstrating how far we have to go to tackle this problem and save our flora from the ravages of overabundant deer.  One is a report by Tom Rawinski on his visit to see deer exclosures on Shelter Island.  The other is a pair of articles about the loss of the flora from deer herbivory in Letchworth State Park by Doug Bassett and Steph Spittal. – Steve Young

CLICK HERE for the Shelter Island story.

CLICK HERE for the Letchworth story.

CLICK HERE for a deer story from East Hampton.

Some rare plants must be fenced in at Mashomack Preserve on Shelter Island to protect them from the deer.

How Phragmites REALLY Gets Around

June 11, 2011

This photo from a saltmarsh on Long Island caught Phragmites in the act of spreading from one marsh to another. It probably happens under the cover of darkness but this crew was headed out in broad daylight.

Click for a larger image. Photo Steve Young