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Ami Ada Wilkinson
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1 Mon 4/24 Activities Learning Target Students will review the concepts of chapter 13. Class Activities Play Classroom Jeopardy to review for test ---work on Chapter 13 review (due Tue) *attached below (scroll down)*

2 Environmental Science Sec Notes Sec Biodiversity at risk About 65 m.y.a Earth experienced a mass extinction by a meteorite impact causing severe climate change mass extinction is the extinction of many species in a short period of time It takes millions of years for biodiversity to rebound after a mass extinction. Current Extinctions biologists agree that we are in the midst of another mass extinction It is expected that from , up to 25% of all species may likely become extinct Species Prone to Extinction species with small populations that live in limited areas are more likely to become extinct endangered species a species likely to become extinct without immediate intervention threatened species are species that have declining populations & are likely to become endangered

3 How do Humans Cause Extinctions? human population growth has accelerated & so has the rate of extinction 4 Major Human Causes of Extinction: (1) habitat destruction (2) Exotic species (3) pollution (4) overharvesting Habitat Destruction & Fragmentation As human populations grow, so does the land needed to build homes & harvest resources almost 75% of the extinctions now occurring can be contributed to habitat loss Florida Panther fewer than 100 east of the Mississippi Invasive Exotic Species exotic species a species that is not native to a particular region threaten native species because they have no natural defenses ex. pythons in Florida Harvesting, Hunting, & Poaching excessive hunting & harvesting can lead to extinction between 1800s & 1900s 2 billion passenger pigeons

4 were hunted to extinction Buffalo were almost lost to excessive hunting poaching illegally harvesting or hunting wildlife some countries have a black market for illegally moving products that contain parts of endangered species Pollution Many chemical agents used by humans are making their way into food webs ex. bald eagle & the pesticide DDT (now illegal in U.S.) Areas of Critical Biodiversity endemic species are native to and found only within a limited area Tropical Rain Forests remaining tropical rain forests cover less than 7% of the Earth s land surface it is estimated that over ½ of the world s species live in these forests unknown # s of species are being lost as land is cleared for farming and cattle grazing.

5 Coral Reefs and Coastal Ecosystems coral reefs occupy a small % of the marine environment but contain the majority of species reefs also provide food & tourism money nearly 60% of coral reefs are threatened by human activity (mainly overfishing & pollution) Islands islands are usually colonized by a limited # of species from the mainland colonizing species may evolve into new species islands end up being the home to many endemic species Biodiversity Hotspots biodiversity hotspots - most threatened areas of high species diversity 25 Hotspots have been identified by international conservationists have high # s of endemic species but are also threatened by human activities mostly includes islands, trop. rain forests, & coastal areas Biodiversity in the U.S. 3 of the biohotspots are within or around the U.S. species diversity is high among groups of land plants

6 (such as pine trees & sunflowers) threats include land used for ag./homes, dams, overuse of water, destructive recreation, & mining

Section 2: Biodiversity at Risk

Section 2: Biodiversity at Risk Preview Classroom Catalyst Objectives Biodiversity at Risk Current Extinctions Species Prone to Extinction How Do Humans Cause Extinctions? Habitat Destruction and Fragmentation