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Invasive Species

April 25, 2016

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invasive species | breaking news

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invasive species | definition

From IUCN:

Introduced Alien Species: “introduced by man into places out of their natural range of distribution, where

they become established and disperse, generating a negative impact”

(link)

  • NISC

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invasives | examples at home

Plants - Herbaceous

  • Poison parsnip
  • Garlic mustard
  • Yarrow
  • Mullein
  • Queen Anne’s lace
  • Dandelion
  • Periwinkle
  • Bull thistle
  • Burdock
  • Curled dock
  • Red clover

Plants - Shrubs

  • Buckthorn
  • Honeysuckle
  • Barberry
  • Oriental bittersweet (vine)
  • Knotweed
  • Phragmites (kind of)

Plants - Trees

  • Norway maple
  • Tree of Heaven
  • Princess tree
  • Black locust
  • Eucalyptus

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invasives | examples at home

Animals - Invertebrates

  • Zebra mussels
  • Emerald ash borer
  • Asian tiger mosquito (Dengue, WNV)
  • Nightcrawlers
  • Giant African snail & Cannibal snail
  • Comb jellies

Animals - Fish, reptiles & amphibians

  • Asian carp
  • Sea lamprey
  • Box turtles
  • Cane toads
  • Pythons

Animals - Birds

  • Europeans: Starlings, Pigeons
  • N American: Double-crested cormorants, ring-billed gulls

Animals - Mammals

  • Rats
  • House mouse (hantavirus)
  • Nutria
  • Rabbit
  • Cats!
  • Dogs

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the invasive species cycle | Asian citrus psyllid

Step 1

  • Identify there’s a problem
  • Who does it affect?
  • Range of problem (map)?

Step 2

  • Identify the cause

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Asian citrus psyllid

Step 3

  • Study disease cycle
    • Vectors of disease

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Asian citrus psyllid

Step 4

Step 5

  • Outreach & education
  • Laws?

Tamarixia radiata

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Recap

Step 1

  • Observe, characterize the problem

Step 2

  • Identify the cause

Step 3

  • Identify and study vectors

Step 4

  • Propose, test, and implement controls

Step 5

  • Education, policy

$$

Cost increases as time elapses and invasion intensifies

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invasive rabbits | a case study

"The introduction of a few rabbits could do little harm and might provide a touch of home, in addition to a spot of hunting."

~ Thomas Austin, ~1860

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Recap

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invasives | why do we care?

  1. Biodiversity loss
    1. 20% of extinctions attributed to invasive species
    2. 400/1300 on ESA are threatened by invasives
    3. Goats caused 8 plant extinctions on Channel Islands
    4. Brown snakes in Guam has extirpated every forest �Bird and many bats, lizards, and more
    5. Leafy spurge won’t be grazed by cattle

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invasives | why do we care?

  • Ecological disruption
    • Tamarisk & salinization/evapotranspiration
    • Norway maple can displace native vegetation
    • Zebra mussels purify water
    • Increase likelihood of other invasives
      1. Feral pigs
      2. Honeybees

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invasives | why do we care?

Economic costs ~ $120 billion/year

  1. To agriculture
    1. Decreased productivity (12%, $33 billion)
    2. Low preference forage ($5 billion to control)
    3. Rats eat ~ $19 billion in food/year
    4. Mongoose eat $50 million in chickens
      1. Introduced to eat rats, only ate Asiatic rats
  2. To tourism
    • Feral cats (not domestic) kill 240 million birds
      • 1 bird = $30
      • Cost estimate based on hunters�birdwatchers ($.40/bird)�Rehabilitation costs
  3. Other
    • Brown tree snakes climb power poles

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invasives | why do we care?

  • Safety concerns

Greenstripping with

Kochia & Crested wheatgrass

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invasive species | Executive Order 13112

By the authority vested in me as President by the Constitution

and the laws of the United States of America,

including the National Environmental Policy Act of 1969,

as amended (42 U.S.C. 4321 et seq.),

Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990,

as amended (16 U.S.C. 4701 et seq.),

Lacey Act, as amended (18 U.S.C. 42),

Federal Plant Pest Act (7 U.S.C. 150aa et seq.),

Federal Noxious Weed Act of 1974,

as amended (7 U.S.C. 2801 et seq.),

Endangered Species Act of 1973,

as amended (16 U.S.C. 1531 et seq.),

and other pertinent statutes,

to prevent the introduction of invasive species and provide for their control and to minimize the economic, ecological, and human health impacts that invasive species cause, it is ordered as follows:

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invasive species | Executive Order 13112

Section 1. Definitions.

(a) ‘‘Alien species’’ means, with respect to a particular ecosystem, any species, including its seeds, eggs, spores, or other biological material capable of propagating that species, that is not native to that ecosystem.

(b) ‘‘Control’’ means, as appropriate, eradicating, suppressing, reducing, or managing invasive species populations, preventing spread of invasive species from areas where they are present, and taking steps such as restoration of native species and habitats to reduce the effects of invasive species and to prevent further invasions.

(c) ‘‘Ecosystem’’ means the complex of a community of organisms and its environment.

(e) ‘‘Introduction’’ means the intentional or unintentional escape, release, dissemination, or placement of a species into an ecosystem as a result of human activity.

(f) ‘‘Invasive species’’ means an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.

(g) ‘‘Native species’’ means, with respect to a particular ecosystem, a species that, other than as a result of an introduction, historically occurred or currently occurs in that ecosystem.

(h) ‘‘Species’’ means a group of organisms all of which have a high degree of physical and genetic similarity, generally interbreed only among themselves, and show persistent differences from members of allied groups of organisms.

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Invasive Species

Sec. 2. Federal Agency Duties.

(a) Each Federal agency whose actions may affect the status of invasive species shall, to the extent practicable and permitted by law,

(1) identify such actions;

(2) subject to the availability of appropriations, and within Administration budgetary limits, use relevant programs and authorities to:

(i) prevent the introduction of invasive species;

(ii) detect & respond rapidly to and control populations of such species in a cost-effective and environmentally sound manner;

(iii) monitor invasive species populations accurately and reliably;

(iv) provide for restoration of native species and habitat conditions in ecosystems that have been invaded;

(v) conduct research on invasive species and develop technologies to prevent introduction and provide for environmentally sound control of invasive species; and

(vi) promote public education on invasive species and the means to address them; and

(3) not authorize, fund, or carry out actions that it believes are likely to cause or promote the introduction or spread of invasive species in the United States or elsewhere unless, pursuant to guidelines that it has prescribed, the agency has determined and made public its determination that the benefits of such actions clearly outweigh the potential harm caused by invasive species; and that all feasible and prudent measures to minimize risk of harm will be taken in conjunction with the actions.

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invasives | characteristics

  • 10% rule
    • 10% escape cultivation
    • 10% of these can survive next generation
    • 10% of these can continue to reproduce
    • 10% of these become pests

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invasives | characteristics

Adaptability in form and function!!

  • Yarrow & phenotypic plasticity
  • American mink = swim, climb, hunt on land

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invasives | characteristics

Aggressive

  • Starlings & nest competition
  • Video
  • Able to deal with humans

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invasives | characteristics

r-Strategists

  • Produce heaps & heaps of offspring
  • Reach maturity quickly
  • Can reproduce asexually
  • Invasive pollinators

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invasives | characteristics

Exploit many resources

  • Diverse food preferences (generalists)
  • Diverse habitat preferences
  • New host has no disease resistance
    • Chestnut blight
    • Dutch elm disease
    • Nectria
    • Smallpox

Exploited by fewer things (because not native)

  1. Fewer predators
  2. Disease resistant

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invasives rabbits | a case study

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invasives | characteristics

Ability to disperse over long distances

  1. Winged seeds
  2. Long viability
  3. Period of dormancy
  4. Fruits
  5. Winged animals

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invasives | arrival

  • Shakespeare
  • Ecosystem services
  • Ballast water
  • Aquarium
  • Shipping pallets
  • Rootballs

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invasives | what makes a good invasion site?

  • Disturbance-heavy
  • Humans nearby
  • Isolated island
  • Ports
  • Globally connected areas
  • High concentrations of specialists

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invasives | management strategies

Negative controls

Positive supports

Mechanical

  • Hand removal, tilling, cutting, extractigators!
  • Solarization

Chemical

  • Poison bait, introducing pathogens
  • Herbicides
  • Sterilization

Fire Control

  • Flame weeding, controlled burns

Biological Controls

  • Introducing predators

  1. Planting
  2. Habitat conservation
  3. Restricting use (LNT)
  4. Restricting behaviors (caves, felt boots)
  5. Education
  6. Thinning
  7. Breeding/hybridization programs

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invasives | back to rabbits

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invasives | case study

Nutria

  • Study organism
  • Stakeholders
  • Possible controls
  • Other considerations
  • Prioritizing