http://www.sprl.umich.edu/GCL/notes2/introspp.html

A BIOLOGICAL INVASION is when a species arrives in an area in which it was previously not found.

An EXOTIC SPECIES is an organism that has invaded an ecosystem in which it did not evolve.

•@ least 10 will successfully colonize

•5 will naturalize

•2-3 will spread and become pests

3% have gone extinct in the past 100 years while another 26% are endangered. Reasons for their decline are:

•habitat destruction 73%•introduced species 68%•pollution 38%•hybridization 38%•overharvesting 15%

•Australia 10%•Canada 28%•Hawaii 18%•France 11%•New Zealand 47%•Spain 15%

•geographic isolation•large amounts of human produced habitat•large amounts of tropical/sub-trop habitat•travel centers

• agriculture• ornamental• hunting and sport• biotechnology• scientific research• pet trade

• ships• air travel• hitchhiking seeds• escapes from agriculture• side effects of habitat alteration

• disease transmissions (smallpox, rabies)

•disruption of the food web, predator-prey interactions• homogenization of the world’s biota: loss of biodiversity•extinction

•hybridization•outcompetition•direct predation (domestic cat, brown tree snake)

•disruption of the ecosystem (increased fire,

N-fixing, change in water table)

•plant pathogens (Ex. Chestnut blight)

•pioneer species•human commensal•prey generalist•habitat generalist•single parent reproduction

What makes something invasive?

Not native

Is able to survive and reproduce

Does something destructive to the environment

PREVENTION•inspection at travel centers•regulations/policiesCONTROL•shooting and trapping•mechanical removal of plants•pesticides•biological control