CHAPTER 3.3 BIODIVERSITY

Biodiversity… How many species live on Earth??? Guess… More than 1.5 million species

What is biodiversity? The number of different species in an area is called BIODIVERSITY.

The value of biodiversity Why is it important to protect biodiversity? -source of beauty and recreation -economic value -ecological value

The value of biodiversity Economic value Ecological value

Economic value of biodiversity Provide food Supply raw materials for clothing, medicine, and other products Offer wildlife tours in rain forests, savannas, mountain ranges, and other locations Offer jobs in tourism, or ‘ecotourism,’ in Brazil, Costa Rica and Kenya

Ecological value of biodiversity All species are connected to one another. A change in number (up or down) will affect other species. A keystone species is a species that influences survival of many other species in an ecosystem. Examples are: 1. sea stars and 2. sea otters

Ecological value of biodiversity Sea stars prey on the mussels that live in tide pools. When sea stars’ number was down, mussels’ number went up, and the ecosystem was not balanced. Sea otters prey on prey on sea urchins. When hunters killed a lot of sea otters for their fur, sea urchin reproduced without control.

Factors affecting biodiversity 1. Area 2. Climate 3. Niche Diversity

1. Area A large area will have more species than a small area. In a big forest, you will find many different species of trees than in a small area. More species Less species

2. Climate There is a lot of different species near equator. For example, forest in Latin America, Southeast Asia, and central Africa are the most diverse ecosystems in the world. These forests cover about 7% of the world’s land, but have more than half of the world’s species.

Climate - map

Climate (continue) It’s not fully understood why there are so much biodiversity. Scientists think it’s because of warm climate. For ex. tropical rain forests have always warm temperature and a lot of rain. Many plants grow year-round, which means food is always available.

3. Niche Diversity Coral reefs make up less than 1% of the ocean’s area. But, reefs are home to 20% of the world’s saltwater fish species. The reef support many species that live under, on and among the coral. That’s why, there is a lot of diversity than on a flat land.

Niche Diversity- coral reef

Gene Pool Diversity Genes are DNA in cells that carry its hereditary information. Organisms receive different combinations of genes from their parents. Genes determine an organism’ characteristics, size, appearance, disease and ability to fight diseases.

Gene Pool Diversity Every individual share many genes, but also has many different combinations of genes. That makes up the total gene “pool” of that species. Species that lack a diverse pool are less able to adapt to changes in the environment.

Gene Pool Diversity- example Some food crops have little diversity. A fungus once wiped out corn crop in the USA. Fortunately, there was a wild variety of corn that was resistant to the fungus. Scientists were able to retrieve this resistant to fungus gene to produce corn that was resistant to the fungus.

EXTINCTION OF SPECIES Extinction- is a disappearance of all members of a species from Earth. Endangered species- species in danger of becoming extinct in the near future Threatened species- species that could be endangered species in the near future.

List of endangered species Chinese’ giant panda Tennesse Purple Coneflower California Tiger Salamander Grizzly Bear Schaus Swallowtail Butterfly Whooping Crane Pipping plower Steller’s Sea Lion

What causes extinction??? Causes of Extinction What causes extinction??? 1. Habitat Destruction 2. Poaching 3. Pollution 4. Introduction of new species

1. Habitat Destruction Habitat destruction is the lost of a natural habitat. Habitat fragmentation is breaking a bigger land into smaller, isolated pieces. Bigger animals may have a trouble surviving because there may not be enough food for them.

2. Poaching Poaching is the illegal killing or removal of wildlife from their habitats. Many animals are killed for fur, skin, teeth, horns, or claws. Or killed animals’ parts are used for making medicines, jewelry, coats, belts, or shoes.

3. Pollution Pollution - the environment is dirty: air, land and water are polluted which may kill or weaken organisms or cause birth defects.

4. Exotic Species Bringing new species, exotic species, to a new land can disrupt an ecosystem. For ex: European sailors began visiting Hawaii, rats from their ships escaped to the islands and reproduced very quickly.

Protecting Biodiversity 1. Captive breeding 2. Laws and Treaties 3. Habitat Preservation

1. Captive Breeding Is mating of animals in ZOOs or wildlife, caring for the young and releasing them into the wild when they are grown. It helps to save animals, but it is expensive to capture, mate and raise young animals.

2. Laws and Treaties The Endangered Species Act prohibits trade in products made from threatened or endangered species. Also, this law requires to set up plans to save endangered species (ex. American alligators and green sea turtles) Laws help protect animals, but they are difficult to enforce (follow).

3. Habitat Preservation The best way to preserve the environment is to protect whole ecosystems, which includes not only endangered species, but also regular animals. Preservations must have the characteristics of diverse ecosystems (be large enough to support the populations that live there and have a variety of niches).

Habitat preservation

Review concepts: What are 2 values of biodiversity?

What are keystone species? Give 2 examples of keystone species.

What is the difference between endangered and threatened species?

What 3 factors affect biodiversity?

What can cause extinction of species?

How does poaching threaten species?

How can biodiversity be protected?

Section 3.3 Assessment 1a. What are two ways in which biodiversity is valuable? 1b. What economic reasons could you give people in the rain forest for preserving the ecosystem? 2a. What are three factors that affect the biodiversity in an ecosystem? 2b. How does each of theses factors affect biodiversity? 2c. Would you expect to find great biodiversity in the tundra biome? Why or why not?

Assessment - continue 3a. Name four human activities that can threaten biodiversity. 3b. Black bears are roaming through a new housing development in search of food, even though the housing development is still surrounded by forest. How can you account for the bears’ behavior?

Assessment- continue 4a. What are three approaches to protecting biodiversity? 4b. For each approach to protecting biodiversity, list at least one factor that might limit its success. 4c. List some ways in which those limitations might be dealt with.