1. Biodiversity
Chapter 10

2. Section 1 What is Biodiversity

3. A World Rich in Biodiversity
Biodiversity – the number of different species in a given area
Tropical rain forests have highest biodiversity on earth
Known species – species that are collected and described scientifically
1.7 million species (most of which are insects)
Unknown species – Species not identified as of yet, located in remote locations
More than 2 million possible (to be identified)
Levels of diversity
Species diversity : Number of species in a given area (most commonly know as biodiversity)
Ecosystem diversity: All the different habitats and ecological processes in an ecosystem
Genetic diversity: All the different genes in all the members of a population
A gene is a part of DNA that determines one particular trait (blue eyes, widow peak)
A World Rich in Biodiversity

4. Benefits of Biodiversity
Species are connected to ecosystems.
Every species is either dependent on or depended upon by at least one other species.
Think food webs, niches
Keystone species – critical to the entire ecosystem
Sea Otters: loss of the otter - led to the loss of kelp beds
Benefits of Biodiversity

5. Benefits of Biodiversity
Species and Population Survival
Genetic diversity is critical to species survival.
Environmental changes affect less diverse populations more
Ice Age – species not adapted to cold die - but species with genes to survive cold live on
If no one in species had cold gene, all die
But what happens to genes in all the species that died?
All other genes lost
Bottleneck effect – When a population is reduced to a few members. Only certain genes get through the event.
Benefits of Biodiversity

6. Industry finds new chemicals in all types of species
Medicines and cures are constantly being found as we locate new species
Industry finds new chemicals in all types of species
Better resistant crops being made because of genetic crossing
Ethics, Aesthetics, and Ecotourism
Should we preserve species because they deserve to be here?
Should we preserve species because they are nice to look at and make our lives beautiful
Ecotourism – a form of tourism that supports the conversation and sustainable development of ecologically unique areas.

7. Time for a reading quiz
That’s all for 10.1

8. Section 2 Biodiversity at Risk

9. Mass extinction – extinction of many species in a short period of time
Five previous mass extinction events
Due to global climate change
Dinosaurs: ice ages and meteorites
Possible cause of the next (current??)mass extinction:
Due to human activities
From 1800 to 2100 up to 25% of all species may become extinct
Endangered species – species that will go extinct if not protected immediately
Usually a small population in a limited habitat
Threatened species – species will become endangered if not protected
Current Extinctions

10. How Do Humans Cause Extinctions
Habitat Destruction and Fragmentation
We use land for homes and food production
In the process – we destroy and fragment the habitats of other species.
Habitat loss is causing 75% of all current extinctions
Florida Panther: one of the most endangered species in North America (due to habitat loss)
How Do Humans Cause Extinctions

11. How Do Humans Cause Extinctions
Invasive species
New species introduced to an environment
Native species have no defenses, and new species have no predators
Kudzu, Cane Toads, Fire Ants
Harvesting, Hunting, Poaching
Passenger pigeon hunted out of existence, bison close
People want rare species as a pet, food, medicine
Monkey brains, shark fins,
Poaching – capturing protected species against the law
Ex: elephants for ivory (tusk) ; tigers for healing properties
Pollution
Chemicals being dumped have harmful effects on other species
Ex: DDT in the food chain caused bald eagle egg shells to weaken
Bald eagle nearly extinct until DDT banned.
How Do Humans Cause Extinctions

12. Areas of Critical Biodiversity
Endemic Species – species that live in a small specific habitat
Tropical Rain Forest
Home to half of world’s species
Most not yet observed, but losing them as we clear the rain forest for farming and housing
Coral Reefs – Most of biodiversity in ocean
A major source of food and ecotourism
In danger due to overfishing, and pollution
Hot Spots – the most threatened areas of high diversity on Earth
Madagascar, Philippines, Florida Everglades, California Coast, Hawaii
United States Biodiversity
We have several of the hotspots (Florida Everglades / coastal regions)
Are we taking care of them?
Areas of Critical Biodiversity

13. Time for a reading quiz
That’s all for 10.2

14. Section 3 The Future of Biodiversity

15. Saving Species One at a Time
When a species is nearing extinction what can be done to help?
Captive breeding
Species are bred in captivity (zoos or shelters) and will be released into wild when enough are bred
California Condor
Preserving Genetic Material
Germ plasm – genetic material from reproductive cells
Stored (usually frozen) for future use.
Same as heirloom tomato seeds!
Zoos and Aquariums
Not just for entertainment
Home for endangered species
Successful breeding programs - Pandas!
Saving Species One at a Time

16. Preserving Habitats and Ecosystems
Conservation Strategies
Focus on whole ecosystem not individual species
Restore native habitats and expand them
Legal Protections - US
Endangered Species Act – passed in 1973
Fish and Wildlife Service must keep list of all endangered or threatened species
Endangered and threatened species cannot be caught or killed. Endangered/threatened plants may not be uprooted
No part of an endangered/threatened species may be sold or traded
US Government cannot do any projects that might impact listed species
The U.S. Fish and Wildlife Service must prepare a species recovery plan
Preserving Habitats and Ecosystems

17. Legal Protection – International
IUCN – International Union for the Conservation of Nature and Natural Resources
Advise governments on endangered species
Publishes a “Red Lists” of endangered species around the world
CITES – Convention on International Trade in Endangered Species
Elephant Ivory Tusks – Poachers after them
CITES made a worldwide ban on selling ivory
Elephant poaching dropped
Biodiversity Treaty
Agreement generated during the Earth Summit (1992 – Rio de Janeiro)
Goal is to preserve biodiversity and ensure sustainable/fair use of genetic resources in ALL countries

18. Time for a reading quiz
That’s all for 10.3