Section 16 4 Threats To Biodiversity Biology Objectives
Section 16. 4: Threats To Biodiversity Biology
Objectives • Why is the preservation of biodiversity important to the future of the biosphere? • What are the consequences of the loss of biodiversity? • How does the loss of habitat eliminate species? • How does an introduced species disrupt stable relationship in an ecosystem?
Preserving Biodiversity • Ecosystems are constantly changing, and populations adjust to these changes • Human actions alter ecosystems in ways that are harmful to biodiversity • Biodiversity is the future of Earth
Biodiversity • Diverse world of living things • A decrease in an ecosystem’s biodiversity will have a ripple effect through the entire ecosystem
Benefits of Biodiversity • Medical and technological advances come from nature • Most prescribed medicines are derived from plants • Many technologies get their inspiration from nature
Loss of Biodiversity • Long term effects • Once a species goes extinct, it is gone forever • Loss of that species can reduce an ecosystems stability and make it difficult for the ecosystem to handle change
Example • Sri Lanka – Ninety-five percent of the natural resources have been depleted – More than 19 frog species have gone extinct • Rain Forest – One of the most threatened biomes – 1% is lost each year to logging and agriculture – Preserving the rain forest will protect the biodiversity of our planet
Loss of Habitat • Governments agencies have developed programs to protect species and their habitats – Monitor & manage numbers – Ensure habitats are available – Protect from overhunting and overcollecting • Human population is responsible for much of the habitat destruction
Habitat Fragmentation • Barrier formed that prevents an organism from accessing its entire home range – Building of roadways or harvesting of forest – Addition of underpasses, overpasses, and corridors to help species to access more of their habitat safely away from the human population
Introduced Species • Introduced Species: Any organism that was brought to an ecosystem as the result of human actions – Prey on or crowd out native species • Invasive Species: Successful under many different circumstances – Niche that can be exploited – Better competitor than native species – Lack of predators to keep population stable
Effect On Native Species • Florida Everglades: – Unique plants and animals that have evolved in a complex ecosystem over tens of thousands of years – The Burmese Python has been introduced • Feeds on small animals, even dogs, and has threatened many of the native bird species • Endangered species protected in the Everglades may be severely affected
Effects On Native Species • Introduced Plants: Kudzu – Introduced in 1876 as a tropical houseplant – Planted as ground cover, but spread quickly – It’s growth rate makes it difficult to control, and it out competes many of the native species • Deprives other plants of the sunlight they need to survive – Also resistant to most pesticides
Economic Damage • Invasive species can have a major impact on humans as well as ecosystem • Australia – Mice were introduced by the British in 1700 s – Become a major pest species inflicting widespread economic damage • Corn and grain crops were damaged • $65 million in revenue lost (1993 -1994)
Output • How might a species of carnivorous fish introduced into a lake have a negative impact on the lake ecosystem? • How might the introduction of a mouse predator help with the mouse problems in Australia? What problems might it cause?
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