Science 10 – Chapter 3.3

How Introduced Species Affect Ecosystems

• Native species are species that naturally inhabit an area– British Columbia is home to about 3,000 species of native plants, including

ferns, wildflowers, shrubs and trees. These native plants have co-evolved with animals, fungi, and microbes to form a complex network of relationships.

Native species

Lilium columbianum (Columbia lily)

npsbc: Native Plant Society of British Columbia

Native Species

Myosotis asiatica (Mountain Forget-Me-Not)

Native Species

Rubus idaeus (Raspberry)

Native Species

Thamnophis sirtalis

Common Garter Snake

Coccinellidae

Lady Bug

• Non-native, exotic, or alien species• Brought intentionally or not intentionally by humans. • Most are harmless or beneficial to the environment

Introduced Species

Salmo trutta

Brown Trout

Introduced species

• Introduced species that take over the habitat of native species or can invade the bodies of native species.

• Competition – have an advantage over natural habitants• Predation – interactions between predator and prey not established• Disease and parasites – gives the less dominant species an upper hand• Habitat alteration– Change light and oxygen conditions– Change soil chemistry– Change nutrient cycling, pollination, energy flow– Spreading weeds– Eat the native birds, reptiles, amphibians, soil organisms, fruits and vegetation

Invasive species

Invasive species

Harmonia-axyridis Asian Lady Beetle

INVASIVE- Introduced 1970’s

Native Ladybug!

9 spots!

• English Ivy in Stanley Park

• In Stanley Park there are 72 non-native, invasive plant species.

• SPES – Stanley Park Ecology Society

Invasive Species

• Australia is host to 56 introduced invasive vertebrate animal species– Cane Toad– Red Fox– European Rabbit– Dromedary Camel– Water Buffalo– Feral cats, pigs, donkeys, and goats!• Feral: descendants of domesticated animals

Australia

• 24 rabbits brought to Australia in 1859 by estate owner Thomas Austin in Eastern Australia

• No predators• Could breed all year with perfect climate• Ate all the farmer’s crops, outcompeted the

native rabbit• In 1901-1907 Australia built the

RABBIT PROOF FENCE to halt western expansion!– Now called State Barrier Fence of Western Australia– 1833 km long!– Following the introduction of myxomatosis (a rabbit

virus) to control rabbits in the 1950s, the importance of the rabbit-proof fence diminished

European Rabbit in Australia

• Eastern Grey Squirrel• The Eastern grey squirrel is one of seven mammals among the 173

invasive species identified by the Garry Oak Ecosystem Recovery Team (GOERT) as a species of concern to Garry oak and associated ecosystems.

Invasive Species in BC

• Eastern Grey Squirrel• Gypsy moth • Scotch Broom

Garry Oak Invaders

• Raises the profile of invasive species• Provides education to the public and land managers on invasive

species• Provides land managers assistance with planning invasive species

management• Conducts on-the-ground management of invasive plants (inventory and

control)• Conducts research activities pertaining to invasive species

management• Provides regional direction on invasive species management

ISCMV: Invasive Species Council of Metro Vancouver

• Prevent – not here but close by!– kudzu

• Eradicate – if we act quickly we can get rid of the species– Common reed

• Control – widespread, very little chance of eradication (not isolated)– Scotch broom – purple loosestrife

• Contain – isolated but with low chance of eradication– Giant hogweed

• Bio-control – scientists are hard at work on this method to use another species to control the problem without creating new problems!

ISCMV put invasive species into 5 categories

Giant Hogweed

• Biomes and ecosystems are divisions of the biosphere– Biotic and abiotic components– Adaptations – the characteristics that help species survive– Biotic interactions – symbiosis, competition, predation

• Energy flow and nutrient cycles support life in ecosystems– Food pyramids, food chains, food webs– Nitrogen, carbon, and phosphorous– Humans and persistent organic pollutants, bioaccumulation

• Ecosystems continually change over time– Natural changes – natural selection, adaptive radiation, natural events– Human influence - carbon footprint, agriculture, resource exploitation– Introduced species – invasive species can destroy an ecosystem

Unit 1 is now complete!