Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Occupancy–abundance relationship wikipedia , lookup
Ecological fitting wikipedia , lookup
Theoretical ecology wikipedia , lookup
Latitudinal gradients in species diversity wikipedia , lookup
Habitat conservation wikipedia , lookup
Biodiversity action plan wikipedia , lookup
Assisted colonization wikipedia , lookup
Invasive species wikipedia , lookup
Introduced species wikipedia , lookup
Invasive Species What is an Invasive Species? • A species that has been introduced or is not native to an environment • Invasive species are generally harmful to the local habitat or native species • Unwanted pest • Not all non-native organisms are invasive More Examples of Invasive Species • Grey squirrel • American beaver • Cane toad Different Routes of Invasion Most invasions are due to human activities: • Plant or pet trade • Commercial shipping • Tourism …and many other routes… Quiz: What Characteristics Make A Good Invader? • • • • • • Rapid reproduction Fast growth High dispersal Tolerant to many different conditions Able to live off many different foods Used by humans The Impact of Invasive Species • Ecological: – Reduce native biodiversity – Direct predation on local species – Spread of disease – Upset balance of local ecosystem The Impact of Invasive Species • Economical: - Very expensive - agricultural pests cause millions of dollars of damage every year! - Very expensive to eradicate invasive species Controlling Invasive Species • Controlling invasive species once they have become established is difficult. • Control is also usually very expensive! • There are four main ways that invasive species are controlled: – – – – Physical control Chemical control Biological control Prevention Physical Control of Invasive Species Controlling plants: • Mechanical – excavation, strimming, etc. • Removal of plants by hand • Installation of growth barriers Controlling animals: • Culling • Trapping and hunting • Putting up barriers or fences Chemical Control of Invasive Species • Chemical control involves applying poison to eliminate invasive species • E.g. Eradication of rats on Henderson Island – Use rodenticide (rat poison) • Insecticides & pesticides to control insect pests • Herbicides (weed-killer) to control plants Biological Control of Invasive Species • Uses a living organism to control invasive species • This organism may eat the invasive species or cause it to become diseased • Biological control agents must be carefully assessed before release to ensure the control species will not become invasive itself Seven-spot ladybird Harlequin ladybird Preventing Invasive Species • Prevention is better than cure! • Preventing invasive species from being introduced somewhere in the first place, or preventing them from spreading if they do arrive, is the key to avoiding long-term harm to ecosystems Barrow Island Case Study • Barrow Island is a small island off the NW coast of Australia that is home to many species that have become rare or extinct on the Australian mainland • This is partly due to a rigorous Quarantine Management System (QMS) operated by Chevron, which prevents invasive species from becoming established on the island