Lecture 22: Vector Control as a Management Option Flashcards Preview

Ecology of Species Invasions > Lecture 22: Vector Control as a Management Option > Flashcards

Flashcards in Lecture 22: Vector Control as a Management Option Deck (16)
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1
Q

Prevention?

A

stop a species from being introduced or established

L> need the most cost effective and practical way to deal with invasions

2
Q

Common trend in impact-density relationship for introduced sp?

A
  • S relationship
3
Q

Indicate where the following priorities go in invasion progression:

  1. Prevention
  2. Eradication
  3. Control
  4. Effective control is no longer possible
A
  • prevention should be before establishment occurs
  • eradication is once establishment has occurred
  • control is for when it is impossible to eradicate them bc they’ve generated a large enough population and have spread
4
Q

What is essential for prevention?

A
  • early detection
  • depends on the effectiveness of monitoring and taxonomical identification
    Problem: most invasions are not recognized right away and are not monitored
5
Q

What are methods of prevention?

A
  1. Vector Control
  2. Quarantine
  3. Habitat management (to reduce vulnerability)
6
Q

Vector control?

A
  • control movement of organisms (travel and delivery)
    ex: Shipping: ballast water treatments
    ex: recreational boats: cleaning them
    ex: Canals: electric barriers
7
Q

Vector Control:

- Ballast water treatment

A
  • mid oceanic exchange
  • filtration
  • chemical sterilization
  • uv light
  • heat treatment-good for cold dep organisms
  • de oxygenation - use bubbled nitrogen
8
Q

Counter productive public information. Explain this with the example of zebra mussels.

A

MYTHS
1. Noah fallacy
- it only takes one
L> “How can I possible be sure I got every last one off my gear”
L> truth: most larvae die, mussels might not reproduce successfully, you NEED HEEPS OF LARVAE. SO REMOVE THEM. Propagule pressure matters

  1. It only takes one mistake
    - “So why bother trying to prevent it”
    L> reality: invasion success increases with propagule pressure
  2. Invasions are inevitable
    - “ SO WHY BOTHER”
    L> Reality: a particular invasion is not necessarily inevitable. But even if the invasion is only delayed, we can buy ourselves time to research methods of control and eradication
9
Q

Quarantine?

A
  • form of vector control
  • prohibits organisms from entering a new range
  • most invasions begin with the arrival of a few individuals. The cost of excluding this is trivial compared to the cost of controlling the established form (rapid growing)
  • the ability off a nation to restrict the movement of invaders across borders is governed by international treaties.
10
Q

Ex of quarantine?

A
  • Asian longhorn beetle
    L> via crate from china
    L> US banned imports of untreated raw lumber and wood packing from ASIA
    *Can did too later but it was too late for Canada though bc the beetle was found here
11
Q

1912 Quarantine Act in USA

A
  • occurred after the chinese chestnut blight fungus happened
  • bans the unauthorized import of plant material to limit introduction of weeds and insects
12
Q
  1. Habitat management

L> agriculture?

A
  • modifications to reduce vulnerability to invasion
    ex: agricultural fields: made diverse using polycultures instead of monocultures
    L> pest insects are lower in polycultures
13
Q
  1. Habitat management

L> Forests?

A
  • diverse habitats compared to agricultural systems. But forestry practices simplify forests for efficiency in timber production
  • in theory, mixed species and mixed age stands would be least subject to damage by insect pests
14
Q
  1. Habitat management

L> Reducing fire freq

A
  • fire favours invasive grasses by removing native competitors and freeing up resources
  • many invasive grasses produce dormant seeds that germinate prolifically after a fire.
15
Q
  1. Habitat management

L> Design of nature parks?

A
  • Goal = reduce propagule pressure :
    1. limit tourist activity
    2. reduce proximity to cities
    3. reduce road access / traffic
    4. keep boundary line simple as possible bc the more circumference = more changes for something to invade

**reduce ratio of perimeter to interior

16
Q

Summary?

A
  1. Prevention is the best and most cost efficient method for managing exotic species
  2. Emphasis should be on controlling vectors rendering habitats less invisible, rather than attempting to control a species after they established
  3. Most important vectors should be targeted
  4. vector control should be linked with monitoring