Invasive Species An introduction

What is a native species? Native species are those that normally live and thrive in a particular community. They occupy specific habitats and have specific niches in their native environment. They have natural predators that help to keep their populations in check. Pink lady's slipper, Cypripedium acaule Red fox, Vulpes vulpes

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). Exotic Species – from another part of the world Introduced Species – implies introduction but not a threat Alien Species – implies introduction to a particular ecosystem- may be a nuisance Non-native species are NOT necessarily invasive!!

10% Rule Only 10% of introduced exotics will live at all due to wrong climate, food availability and other factors – Only 10% of introduced exotics will live at all due to wrong climate, food availability and other factors – Of the 10% that live, only 10% will actually breed and become invasive (EPA estimates) – Of the 10% that live, only 10% will actually breed and become invasive (EPA estimates) – 6,500 established invasive species in the U.S. (USGS) – 6,500 established invasive species in the U.S. (USGS)

Invasive Species Plants Insects Diseases

What is a non-native, invasive species? A non-native species that adversely affects habitats and biodiversity. Emerald ash borer, Agrilus planipennis, has killed millions of ash trees in the mid-west and has recently been found in Pennsylvania and surrounding states. Has not been documented in Delaware Japanese stilt grass, Microstegium vimineum, becomes established on recently disturbed areas and outcompetes native plants, reducing biodiversity.

Common characteristics of invasive species Invasive species in general: Have few 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 ability to tolerate a wide-range of environments year. Discussion: how would these characteristics enable a species to become invasive?

Spread of the Zebra Mussel

Geographic Barriers: Oceans Mountains Deserts Large Lakes Barriers are in the eye of the beholder: what is a barrier for one species is not a barrier to another e.g. mountains may restrict plant distributions, but not birds What prevents species from dispersing globally?

Globalization: The key to introduction Species are being transported across these barriers at an increasing rate owing to human movement and commerce. Major vectors are planes, ships and humans In some cases, the rate of spread may be 50,000 times greater than by natural dispersal!

Vectors of Invasion Intentional Release of Target Species into Containment: - Escapes from zoos and botanical gardens - Farmed species - Aquaculture - Research Intentional Release of Target Species into the Environment: - Plants for agriculture, forestry, soil improvements - Ornamental Plants/Naturalization societies - Birds and mammals for hunting - Biological control - Released pets and pet trade

Release of Non-Target Species (AKA “Accidental” Releases): Contaminants or hitchhikers with produce, ornamental plants and aquaculture Timber Contaminants of seed stock Cars Planes Hitchhikers with packing material, cargo Ballast in ships Tourists/Luggage Canals/manmade environmental structures Vectors of Invasion

Ballast Water Problem

Global Invader: European Starling 60 starlings were released in Central Park in 1890 by a Shakespeare fan, the population today is estimated at 200 million. Habitat generalists, able to exploit a large variety of habitats, nest sites and food sources Large flocks, highly colonial- aggressive and gregarious Impacts: Seed dispersal Agriculture damage Outcompete native species (cavity nesters)

Invasion of the States

Impacts of invasive species Economic impacts: Invasive species are responsible for tremendous economic losses through loss in forest and agricultural productivity and the spread of diseases that impact humans. European starlings, Sturnus vulgaris, spread diseases to wildlife, livestock, and humans, damage agricultural crops, and displace native birds. Their damage to agricultural crops is estimated at $800 million annually.

Impacts: Economical Estimated annual costs associated with non-native species: Groupcosts (in millions) Plants (purple loosestrife, weeds)34,000 Mammals (feral pigs, rats)37,000 Birds (pigeons, starlings) 2,000 Fishes 1,000 Arthropods (ants, termites, other pests)19,000 Mollusks (zebra mussel, asian clam) 1,200 Microbes (plant pathogens, animal disease)41,000 All organisms over $136 billion per year Source: Pimentel et al BioScience

Delaware Ecosystems at risk: Marine/Estuarine Ecosystems Terrestrial Ecosystems Freshwater/Riparian Ecosystems

Impacts: Ecological Direct competition with native species Loss of species diversity Disrupts interactions in natural communities and food webs Affects entire ecosystem functions (water availability and nutrient cycles)

Forest Invader: Japanese Stilt Grass It can become established and live in a wide variety of habitats Each plant produces hundreds of seeds that can remain viable in the seed bank for upward of five years. Seed can be transported long distances by water or contaminated hay, seed mix and soil. Plants also reproduce asexually. They form roots at the nodes, which allows for new vegetative stem growth. People can spread stilt grass by carrying the seeds on their shoes, equipment and vehicles. Monoculture of Japanese Stilt grass prevents the establishment of new tree seedlings and native herbaceous plants decreasing the amount of food for wildlife.

Some invasive species kill native species About ¼ of the hardwood trees in the Eastern US used to be American chestnut. The invasive chestnut-blight fungus killed most American chestnut throughout the eastern US by American chestnut, Castanea dentata, at Grey Towers National Historic Site in Milford, PA, circa 1905 American chestnut infected with chestnut blight fungus, Cryphonectria parasitica

Indirect Impacts: Natural Communities Hemlock woolly adelgid is killing Eastern hemlock trees throughout the northeast. Eastern hemlock forests play an important role in maintaining stream temperatures and oxygen levels favorable for brook trout. Hemlock mortality leads to increased water temperatures and oxygen levels, and therefore reduced brook trout populations. Hemlock woolly adelgidHemlock mortality along stream bank Hemlock woolly adelgid infestation

Disturbances: A “root” in the door     The most successful invaders are those that are pre-adapted to disturbances. Natural Disturbances mature trees naturally die lightening strikes large winds can damage tree crowns fire Man-made Disturbances logging development recreation (trails)

Stages of Invasion 1.Opportunity (transport) 2.Establishment 3.Spread (different characteristics may be important at different stages)

Control Methods Prevention (education, restrictions, monitoring) Prevention (education, restrictions, monitoring) Eradication (time sensitive) Eradication (time sensitive) Physical (manual & mechanical) Physical (manual & mechanical) Cultural (ecosystem management) Cultural (ecosystem management) Biological (natural enemies) Biological (natural enemies) Chemical (pesticides) Chemical (pesticides) Integrated Pest Management (combination of methods – OFTEN MOST EFFECTIVE) Integrated Pest Management (combination of methods – OFTEN MOST EFFECTIVE)

Biological – control species can become invasive, takes a long time to research Biological – control species can become invasive, takes a long time to research Chemical – may kill native species Chemical – may kill native species Physical – may miss removing some of the invasive species Physical – may miss removing some of the invasive species Prevention – apathy and lack of awareness Prevention – apathy and lack of awareness Side effects of control methods

Public Outreach: What you can do! When boating, clean your boat thoroughly before transporting it to a different body of water. Clean your boots before you hike in a new area to get rid of hitchhiking weed seeds and pathogens. Don’t move firewood (it can harbor forest pests like emerald ash borer). Don't release aquarium fish and plants, live bait or other exotic animals into the wild. If you plan to own an exotic pet, do your research and plan ahead to make sure you can commit to looking after it. Volunteer at your local park, refuge or other wildlife area to help remove invasive species. Help educate others about the threat.

Laws & Regulations Federal -NISA -National Invasive Species Act – ANS “Aquatic Nuisance Species” Task Force -Executive Order on Invasive Species -The Lacy Act- regulates import and transport of species -USDA APHIS -CDC Center for Disease Control

Our mission is to “Protect Delaware’s Ecosystems by Preventing the Introduction and Reducing the Impact of Non-native Invasive Species.” Delaware Invasive Species Council

USDA Animal and Plant Health Inspection Services (APHIS) Plant Protection and Quarantine (PPQ) regulates the importation of plants and plant products under the authority of the Plant Protection Act. PPQ maintains its import program to safeguard US Agriculture and natural resources from the risks associated with the entry, establishment, or spread of animal and plant pests. Cooperative Agriculture Pest Survey (CAPS) ensures that new introductions of harmful plant pests and diseases are detected as soon as possible, before they have a chance to cause significant damage. State cooperators carry out surveys for high-risk pests.

Outreach publication, signage/ Education materials BINDERS!! DISC Website