Invasive Species:an overview

Field Biology

October 18, 2016

Carrie Brown-Lima Director, NYISRI Cornell Universitycjb37@cornell.edu

The Ecology of Invasions by Animals and Plants

1958 –Charles S. Elton

“…two rather different kinds of outbreaks in populations: those that occur because a foreign species successfully invades another country, and those that happen in native or long established populations. This book is chiefly about the firstkind – the invaders”.

Non-Native

Alien

Introduced

Exotic

Invasive

Pests

Non-Indigenous

Non-NativeAlien

Introduced

Exotic

Invasive

Pest

Non-Indigenous

Working Definitions in New York State and US

Invasive species: a species that is nonnative to the ecosystem under consideration, and whose introduction causes or is likely to cause economic or environmental harm or harm to human health. (To be considered invasive, the harm must significantly outweigh any benefits)

What is a native species?A species that is a “part of the balance of nature” that has developed over hundreds or

thousands of years in a particular region or ecosystem.

– The word native should always be used with a geographic qualifier (that is, native to New York [for example]).

– Only species found in this country before European settlement are considered to be native to the United States.

Non-Native Species = “Bad”Native Species = “Good”

What is a non-native species?

A species living outside its native distributional range, which has arrived there by human activity, either deliberate or accidental.

*Non-native species are not necessarily invasive.

Native Nuisance Species: Examples from NYS

Working Definitions in New York State and US

Invasive species: a species that is nonnative to the ecosystem under consideration, and whose introduction causes or is likely to cause economic or environmental harm or harm to human health. (To be considered invasive, the harm must significantly outweigh any benefits)

Impacts of invasive species

Economic

Ecological

Health

Economic Impacts of Invasive SpeciesNationwide:

Estimated $167 billion annual cost

• Agricultural productivity

• Forest Production

• Lake productivity (Fisheries)

• Impact on recreation (fishing,

boating, swimming)

• Ornamental/landscaping

$2-3 million lost from raspberry and blueberry industry due to spotted wing drosophila in 2012

$3.5 billion annual costs of non-native beetles

Hydrilla in Cayuga Lake –$1.5 million in treatment costs

Ecological Impacts of invasive species

• Reduced biodiversity

• Species endangerment

• Ecosystem functioning

Health Impacts of Invasive Species

• Poisonous or photo-dermatitis

• Disease

Hydrilla discovered in Cayuga Inlet in August of 2011

Photo credit: Robert L. Johnson

16

Hydrilla in the Cayuga Lake Watershed

Hydrilla verticillata

Cayuga Lake Watershed HydrillaEcological Impacts

• Outcompetes beneficial native species

• Thick mats of vegetative growth

• Reduces overall native habitat and water quality

• Oxygen deficits Fish kills

• Potential toxic blue-green algae outbreaks

Economic Impacts

• Impairs boating, fishing, swimming & recreation

• Cripple tourism and commerce, and decrease property values

• Flood capacity of waterways reduced

• Costs millions of dollars to manage on large scales

2-3 years…. 4-5 years?

17

$1.5 million spent for treatment since 2011

Emerald Ash Borer (EAB)

Ash trees in a Toledo, Ohio neighborhood in June 2006. Credit: D. Herms

Toledo, Ohio trees after emerald ash borer in August 2009.Credit: D. Herms.

• From Asia • First identified in Detroit, Mich., in 2002, • Has become the most destructive forest insect to ever

invade the U.S. Tens of millions of ash trees have already been killed

• Now found in 18 states, along with Ontario and Quebec. • Predicted to wipe out all ash trees in the US

Common characteristics of invasive species

Invasive species in general:

• Have few or no natural predators, competitors, parasites or diseases

• Have high reproductive rates

• Are long-lived

• Are generalists

• Are pioneer species

Characteristics that make Zebra mussels a good invader include its ability to tolerate a wide-range

of environments, and high reproduction rate; female mussels release up to 100,000 eggs year.

Invasive Establishment

Transitions that a species must overcome to become invasive

– Transport pathway– Introduction– Establishment– Spread

The “10s Rule”– 10% of introduced species

will survive after arrival– 10% of that will become

invasive

How do invasive species arrive?

Accidental

Ballast water of ships

Shipped materials (wood packing, etc)

Plants and produce transport

Escape from captivity (aquarium, bait, etc.)

How do invasive species arrive?

Intentional

For ecosystem service

For agricultural or landscape use

Biocontrol (before screening was mandated)

Aesthetic

Shakespeare enthusiasts?

Prevention – “Targeting Pathways”

Early Detection

Needed to have Structure

Needed To Be Organized

Would lead to Success

So we organized for efficiency by:

1. Developing Priority Conservation Areas, PCA’s.2. Developing Early Detection Protocols.3. Developing Rapid Response Protocols.

Realizing that surveying and responding is based on available resources, we recognized early on that we cant be everywhere detecting and responding to everything.

Eradication• Goal – Eliminate all individuals and seeds

Weed-free for 3+ years• Low likelihood of species returning (10 year timeframe)• Greatest success for small infestations (< 2.5 acres)

Exclusion or Containment• Goal – Prevent infestation from

spreading to uninfested areas• Best for slow spreading species and when

effective barriers exist• May require long term maintenance

Suppression• Goal – reduce the population or reproductive

output to a level that maintains native species or ecosystem processes

• May require long term maintenance

Potential Control Strategies

Taken from NY Natural Heritage Program Imap presentation

Control options

Chemical Physical Removal Biological Control

Physical Removal/Mechanical Control

Photo credit: Robert L. Johnson

33

Chemical Control

Biological Control

Biological Control ofPurple Loosestrife (Lythrum salicaria)

Leaf beetles: Galerucella calmariensis & G. pusillis

Manitoba Montezuma

Control options: Risk vs Benefits

Chemical Physical Removal Biological Control

Decide not to take action?

How do we know if we were successful?

OR

HEALTHY ECOSYSTEMS

HEALTHY ECOSYSTEMS

Driver: Hemlock Woolly Adelgid(Adelges tsugae)

Passenger: Japanese Stilt Grass(Microstegium vimineum)

Common (often unfounded) assumption with “passenger invasives”:

?

Deer drive stilt grass abundance

Davalos et al. 2015 Forest Ecol. Manag.

Davalos et al. 2015 Biological Conservation

Seeding experiment: Higher native trillium

emergence in stilt grass

Davalos et al. 2015 Forest Ecol. Manag.

Transplant experiment:Adult trillium are taller and have more stems when deer excluded

Multiple Stressors: More than one driver?

Growing debate surrounding invasion biology

“Invasive species differ significantly from non-invasive species (Thompson 1994), but the attributes of invasive aliens are not unique; most are shared by invasive native species. “

From: Native and Alien Invasive Plants: More of the Same? Author(s): Ken Thompson, John G. Hodgson and Tim C. G. Rich Source: Ecography, Vol. 18, No. 4 (Dec., 1995), pp. 390-402

Impact matters more than originEx: Southern Pine Beetle in New York

• First documented occurrence in NYS (Long Island) in 2014 (since first systematic entomological records collected in 1800s)

• Native to the southern pine ecosystem and the pine barrens ecosystem.

• Highly destructive forest pest with the ability to rapidly change forest type (e.g., from pines to scrub hardwoods).

Expert Opinions: Native Pest or Invasive Species?

“This is a native species and I feel quite certain that

this is all about climate change. It must have been

brought north many times but for some reason, now

it’s surviving in more northern locations than in the

past.”

“I feel SPB is invasive because 1) there are no

past records of its presence in Long Island; and

2) because the Long Island population of pine

is disjunct from others”

“In my opinion, SPB is an invasive native, but

not exotic pest expanding into New York State

as a result of climate change or extreme

weather events. Invasive does not necessarily

mean exotic; SPB is an invasive pest even in

NC.”

What difference will this make?

• Where do the management resources come from?

• Who is responsible for addressing the problem?

“The administrative decision of whether SPB is an “invasive species” under New York law should not affect the practical responses.” Dr. Matt Ayres, Dartmouth College

Challenges for invasive species management:

• Many species – which ones, where?

• Understanding new and existing invasive species, species interactions/impacts

• Setting objectives and measuring real results

• Best control methods – quantitative not qualitative

• Were we successful – cost / benefits of control?

Invasive Species in NYS

389 species of non-native (varying levels of

invasiveness) plants, animals, insects, pathogens documented in New York(was 346 a year ago)

Solutions in New York

• In 2003 Gov. Pataki called for an Invasive Species Task Force (ISTF) to explore invasive species issues and provide recommendations

• Published report in 2005 with 12 recommendations to address invasive species in the state

Building a Strategic System

Coordination and Communication Funding provided by:

New York State Environmental Protection Fund

New York's Online Invasive Species

Database and Mapping System

Carrie Brown-Lima

Director, NY Invasive Species Research Institute

Fernow Hall, Room 216

cjb37@cornell.edu

www.nyisri.org