Invasive Species Flashcards
Define Exotic Invasive Species.
Plants, animals, and microbes not native to a region introduced accidently or intentionally.
What are the 3 characteristics of Invasive Species?
- Out-compete native species for available resources
- Reproduce prolifically
- Dominate regions and ecosystems
Are all exotic species invasive?
- No.
- About 50,000 exotics introduced in US.
- About 4,300 of the 50,000 exotic species in the US are considered invasive
What are exotic invasive species like in their native range?
- Usually not pests
- Populations managed by: Predators/parasitoids, Diseases, Co-evolution, Competition, etc.
List 4 examples of non-arthropod exotic invasive species.
- Purple loosestrife: plant that takes over native wetland areas
- Kudzu: covers native plants and dominates
- Zebra mussels: native to Asia; take over and displace the natives; clog tubes and pipes
- Python: invading Florida everglades
What is the status of exotic forest insects?
- About 360 exotic insects in forests
- About 30% are pests
- $2.1 billion / year in losses
- Frequency is increasing because of increased global population and commerce and travel
List 3 main consequences of Invasive Species.
- Loss of biodiversity
- Ecological impacts
- Economic damages
What are the characteristics of Loss of Biodiversity?
- 2nd to human population growth and activities as a cause of loss of biodiversity
- 42% of species on endangered or threatened list result of invasive species (competition, displacement, predation, hybridization)
Name 5 ecological impacts of Invasive Species.
- Competition with native species
- Ecosystem changes
- Ecosystem domination
- Introduce disease
- Hybridization
What are economic damages of Invasive Species?
- Invasive species (all): est. $125-140 billion/yr
- 25% of US agriculture lost to foreign pests
- Invasive invertebrates: $20 billion/yr in agricultural and forest damage
List and describe the 5 steps in a Biological Invasion.
- Pre-introduction: Prevention, risk assessment
- Introduction: Founders or source population (accidently or intentionally)
- Establishment: Successful
- Spread: Multiply, mate and reproduce, disperse
- Impacts: Depends on the species; Environmental $ loss
What are the general policy and management options for each step in biological invasion?
- Pre-introduction: Prevention
- Introduction: Early detection, rapid response, and eradication
- Establishment/Spread: Control and slow the spread (so that research can catch up)
- Spread/Impacts: Human adaptation (change behavior and bear the costs)
List 3 areas of current research on Invasive Species.
- Prediction and prevention
- Detection and monitoring
- Management and restoration
What is the debate over Invasive Species?
- Should we actively manage exotic invasive species or should we do nothing and “live with it”?
- One view: We’re causing the problem, it’s our responsibility to manage it.
