7 Flashcards
(15 cards)
What is an invasive species?
A mostly exotic species that displaces, outcompetes, or harms native species, often altering ecosystem function.
What are some interchangeable terms for invasive species?
Exotic, non-native, non-indigenous, alien, introduced.
How do invasive species threaten biodiversity?
By excluding native species, spreading disease, disrupting food webs, and degrading ecosystem quality.
What are the three stages of invasion?
Opportunity (transport), establishment, and spread.
What makes islands particularly vulnerable to invasions?
Lack of native predators, competitors, or diseases, and a history of evolutionary isolation.
What traits make invader species successful?
High reproductive rate, short generation time, generalist diet, high dispersal ability, and high genetic variability.
What types of ecosystems are most vulnerable to invasive species?
Disturbed, low-diversity, early-successional systems with human activity and no natural predators.
Give an example of a classic invasive species and its impact.
Purple loosestrife: dries wetlands, alters habitat structure, and outcompetes native plants.
What is biotic resistance?
The ability of diverse, undisturbed ecosystems to resist invasion due to strong native species interactions.
What is biotic homogenization?
The process by which ecological communities become more similar due to habitat loss and species introductions.
Name two types of species introductions.
Intentional (e.g. pest control, horticulture)
Accidental (e.g. ballast water, fruit shipments)
Why are fire ants considered a harmful invasive species?
They reduce native insects and ground-nesting animals, disrupt agriculture, and can cause ecological cascades.
What is an example of an unintentional species introduction with major impacts?
Burmese pythons in the Everglades, which prey on native wildlife and disrupt food chains.
What are two main types of invasive species control?
Chemical control (e.g. pesticides) and biological control (introducing predators or competitors).
What is the best method to manage invasive species?
Prevention—stopping the introduction before it happens using the precautionary principle.
