How Introduced Species affect Ecosystems

3.3

Agenda•3.3 Notes•BBC Video on pythons •Video on Sea Lamprey •Work on review package 3.3 •Work on review package 3.1-3.2 •Work on Practice Problems

Native Species•Organisms that naturally inhabitant a given area•For example: “Cattails” at Lily Lake in Merrit

Introduced Species•Non-native organisms that enter a new ecosystem•Can be distributed by people, intentionally or by accident.

Introduced Species•These species are typically harmless, or sometimes beneficial. • i.e. loosestrife-eating beetle

Invasive Species•Harmful introduced species•Can take over the habitat of native species• https://www.youtube.com/watch?v=Qy67XU6xEi8

Ex. Purple Loosestrife

Invasive Species•Why are they so harmful?

–Have no predators–Could aggressively compete (negatively affect native species)

–Reproduce quickly

Invasive Species• Invasive species can weaken ecosystems–Make them more susceptible to disease and parasitism by micro-organisms

•Some invasive species can change, both physically and chemically, the make up of an ecosystem = Habitat alteration!

|Cattails:Native Species

Purple Loosestrife:Invasive Species

Loosestrife eating beetle:Introduced Species