Chapter 3 3 How Introduced Species Affect Ecosystems

Chapter 3. 3 How Introduced Species Affect Ecosystems

Road map for today q Go over and mark WB pages 46 -49 q. Warm up game q. Native vs. non-native species q Invasive species and their impacts (4) q Workbook pages 52 -55

What’s happening here?

Warm-up game: Name That (Invasive) Species

Warm-up game: Name That (Invasive) Species

Warm-up game: Name That (Invasive) Species

“A public health hazard, hogweed's clear, watery sap has toxins that cause photo-dermatitis. Skin contact followed by exposure to sunlight produces painful, burning blisters that may develop into purplish or blackened scars. ” -Noxious weeds, King County, Washington http: //www. kingcounty. gov/environment/animals. And. Plants/noxious-weeds/weedidentification/giant-hogweed. aspx

Warm-up game: Name That (Invasive) Species

Warm-up game: Name That (Invasive) Species Video http: //www. youtube. com/watch? v=g. Fch. SGI 0 j. B 4

Native species vs. non-native species • Native species are plants and animals that naturally inhabit an area • Introduced species new species of plants and animals introduced accidentally or on purpose – A. K. A. foreign species, non-native species, exotic species, or alien species – Many of these species are harmless, or sometimes even beneficial – Occurred due to immigration over past 400 years

Invasive species • Organisms that can take over the habitat of native species or invade their bodies, thus weakening immune system.

Invasive Species • Often have high reproductive rates, are aggressive competitors, and lack natural predators in new habitats • Have potential to dramatically change ecosystems through – Competition – Predation – Disease and parasitism – Habitat alteration

Impacts of invasive species • Competition: invasive species compete against native species for essential resources such as food and habitat • Predation: invasive species can have more impact on a prey population than native predators, as prey may not have adaptations to escape or fight them off American Bullfrog

Impacts of invasive species • Disease and Parasitism: can weaken the immune response of an ecosystem’s native plants and animals, influencing humans • Allows opportunity for less dominant species to outcompete other species European Starling outcompetes western bluebirds for nesting habitat Norway Rat Eats ground-nesting sea birds’ eggs

Impact of Invasive Species • Habitat alteration: make a natural habitat unsuitable for native species by changing its structure or composition • • Change light level Decrease dissolved O 2 Change soil chemistry Increase soil erosion • E. g. , scotch broom acidifies soil

West Nile Virus • Introduced to U. S. in 1999, started causing deaths in birds and illness in humans in NY • Carried by mosquito How is this related to invasive species? http: //www. youtube. com/watch? v=EVk 5 rf. IA 4 k. U

Pick two • Silent Invaders • http: //www. youtube. com/watch? v=9 JQ 6 o. Hjpeq U • Spit • http: //www. youtube. com/watch? v=eqo. T 8 tc. Zq 6 k • Death Scent • http: //www. youtube. com/watch? v=8 Lk. RChk. UIR M

Habitat alteration • Eurasian Milfoil first ID’d in Okanagan Lake in 1970. • Forms wide, dense mats at lake surfaces • Cuts off sunlight • Interferes with boaters/swimmers • Can grow from fragments spreads!!!

Saving an Ecosystem Under Siege • Often requires human intervention to save established ecosystems • Garry Oak Ecosystem Recovery Team (GOERT) is trying to save several areas because Garry Oak trees: – Are a Keystone Species – May be better suited for future than Douglas fir forests • Scotch broom, and English ivy are biggest threats

Garry Oak Forests • 95% of the original ecosystem has been lost to urban development • The remaining 5% is threatened by invasive species.

Cleaning up the fragments of the chapter q. Native species q. Non-native species q. Invasive species q. Impacts of invasive species (4) q Workbook pages 52 - 55 q Next class…Ch 3 review! Coming up… Ch 3 Celebration of Learning!