alien species

Alien species

Alien species

DefinitionsIntroduced (non-native, exotic) - species introduced deliberately or accidentally from somewhere else

Domestic/Feral (released pets, livestock and game animals) - can spread disease, compete with native species

Human commensal or subsidized (out of control natives) - native species that benefit from our land use (disturbance)

Invasive species - species that spread subsequent to establishment usually at some cost.

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Nature of introductionsIntentionalUnintentional3

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Vectors of invasion into ecosystems4

Vectors of invasion into ecosystems5

Why study biological invasions?ConsequencesUnique opportunities for research6

Estimated annual costs associated with non-native speciesGroupCost (in millions, US $)Plants34,000Mammals37,000Birds2,000Fishes1,000Anthropods19,000Mollusks1,200Microbes41,000All organisms over $136 billion per year

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Hypotheses for the success of introduced species8

Characteristics of invasive species9

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Stages of invasion10

What makes certain ecosystems more vulnerable?11

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