Presentation on theme: "Chapters 23 and 24. 23 -extinction: disappearance of a species from all or part of it’s geographical range. -More than 99% have become extinct -Mass extinctions."— Presentation transcript:
23 -extinction: disappearance of a species from all or part of it’s geographical range. -More than 99% have become extinct -Mass extinctions (been 5) -Biodiversity: variety of species. -Habitat destruction: disturbing part of an ecosystem, ex: cutting down trees. -Humans number 1 contributor (with 50% being commercial harvesting) -Invasive species: non native species, introduced usually by humans
Deforestation -Loss of biodiversity -½ of all rainforests are gone -Growing populations huge factor -Mostly in developing nations -100’s to 1000’s of years to regenerate Aquatic destruction -Coral reefs and wetlands are number one areas -Pollution and overfishing large causes -Draining for water and development another huge cause
Everglades -In Florida -Prime real-estate, being drained and blocked off -Over half of all wetlands in the US have been lost Aral Sea -We covered already in detail Biodiversity -Humans benefit from high biodiversity, so why are we destroying it -Directly threatens human health by destroying.
GMO’s: genetically altered plants (by humans) -Good and bad -Loss of biodiversity -Good for creating new and better food sources for humans -Creates draught and pest resistant plants -Bad, when a disease or pest strikes, wipes everything out Medicines -Natural chemicals for medicine -40% of all medicines used comes from plants -Unclear as to how many cures can still be found -Lose the plants, lose the cures Wilderness - Area where the ecosystem is relatively untouched.
Gene bank: secure place where seeds, plants, and genetic material are kept. ESA: endangered species act: 1973, requires a list of all species in the US that are considered in danger. -Handled by the USFWS -Threatened species may not be caught or killed -May not be disturbed -Products made from them may not be bught or sold. -Gov. can not construct any project in their habitat -Hard to enforce
24 Conservation: strategy to reduce the use of resources through decreased demand and increased efficiency. -Humans waste more than any thing else -Energy conservation one way -Reduce, reuse, and recycle Recycling: using waste materials to produce new items Reduce: use less Re-use: change from one form to another useful form -you should know examples of each Preserve: area of land or water set aside for the protection of the ecosystem in that area. - Only 19% of the worlds ecosystems are preserved.