1. HOW INTRODUCED SPECIES AFFECT ECOSYSTEMS Introduced Species

2. Native Species Native species are plants and animals that naturally inhabit an area Slide 2

3. Introduced Species Introduced species are also called foreign species or non-invasive species Introduced species are plants or animals that are brought into an ecosystem and are usually beneficial or harmless to the ecosystem Slide 3

4. Invasive Species Some introduced species are invasive and can destroy ecosystems Invasive species are organisms that can take over the habitat of native species or invade their bodies, thus weakening their immune systems Slide 4

5. Impact of Invasive Species Invasive species have high reproduction rate, are aggressive competitors, and lack natural predators in new habitats Such introduced species can affect native species through:  Competition  Predation  Disease  Parasitism, and  Habitat alteration Slide 5

6. Competition Introduced invasive species compete against native species for essential resources such as food and habitat The original community has adapted to sharing resources, but invaders disturb this balance  Example: Kudzu Slide 6 First introduced to help control soil erosion “The Vine that Ate the South” – runs rampant in the Eastern US

7. Predation Introduced predators can have more impact on a prey population than native predators, as prey may not have adaptations to escape or fight them  Example: Burmese Pythons infest Everglades National Park Slide 7 Have very few predators Alligators up to five fee long have been found inside the bellies of captured pythons

8. Disease and Parasites An invasion of parasites or disease-causing viruses and bacteria can weaken the immune responses of an ecosystem’s native plants and animals, including humans This weakening provides less dominant species to outcompete other species, severely altering the ecosystem  Example: The parasitic sea lampreys in the Great Lakes in Eastern Canada Slide 8

9. Habitat Alteration Introduced invasive species can make a natural habitat unsuitable for native species by changing its structure or composition They may change the light levels, decrease dissolved oxygen in water, change soil chemistry, or increase soil erosion They can upset the balance of nutrient cycling, pollination, and energy flow Example: Wild boars are one of the world’s worse invasive species, damaging the environment by rooting, wallowing, and spreading weeds that interfere with natural succession Slide 9