1. Review
Biodiversity

2. Evolution Change over time
Achieved by a change in a population’s genetic make-up over many generations
Speciation: development of a new species
- may occur when a population is isolated
- may occur from hybridization
(ex: crossing plants)

3. Human Impacts on Biodiversity
Human Population Increase
Human Activities
Direct:
Pollution
Deforestation
Destruction of Natural Resources
Indirect:
Climate Change
Loss of Biodiversity

4. Natural Capital of Forests
Ecological-
purify water and air
reduce erosion
store atmospheric carbon
Economical-
lumber
fuel wood
jobs
recreation

5. Effects of Deforestation
Decreased fertility of soil
Runoff of soil into aquatic systems
Extinction of species
Loss of habitat
Regional climate change
Release of CO2
Increased flooding

6. Deforestation
Greatest cause of deforestation is conversion of forests into pastures for agricultural use.

7. Forest Management Methods
Clear Cutting- lowers biodiversity and leaves a barren landscape
Selective Cutting- removing some trees, leaves a forest with high biodiversity and beauty
Shelter-wood Cutting- removes mature trees in groups over many years and leaving many trees to reseed the area
Seed- tree cutting- removing all seed trees and leaving the large mature seed bearing trees

8. Sustainable Forestry
Identify and protect forest areas high in biodiversity
Stop clear-cutting on steep slopes
Prohibit fragmentation of remaining large blocks of forest
Sharply reduce road building into uncut forest areas
Certify timber grown by sustainable methods
Shift government subsidies from harvesting trees to planting trees

9. Forestry
In 2003, U.S. Congress passed the Healthy Forest Restoration Act:
Allows timber companies to cut medium and large trees in 71% of the national forests.
In return, must clear away smaller, more fire-prone trees and underbrush.
Some forest scientists believe this could increase severe fires by removing fire resistant trees and leaving highly flammable slash.

10. Importance of Biodiversity
Stability- stable environment
Genetic reserves- genetic diversity
Medicinal- medicines
Agricultural- food
Industrial- building homes; things we use
Scientific- experimental; new technology
Aesthetic- beautiful
Ethical- what should we do regarding the environment
Religious- religious beliefs regarding environment

11. Extinction
The current extinction crisis is the first to be caused by a single species- US!
This is happening faster than ever; a few decades versus thousands to millions of years.
Humans are eliminating not only the species but, the environment. Ex. Tropical rainforest

12. Endangered
Species with so few survivors that the species could soon become extinct.
Ex: Leopard

13. Threatened
Wild species that is still abundant in its natural range but is likely to become endangered because of a decline in numbers. Ex: Northern Sea Lion

14. Species Vulnerable to Extinction
Low Reproductive Rate
Specialized Feeding Habits
Feed at high trophic levels
Large size
Specialized nesting or breeding areas
Found only in one place or region
Fixed migratory patterns
Preys on livestock or people
Behavioral Patterns

15. HIPPO
Conservation biologists summarize the most important causes of premature extinction as “HIPPO”:
Habitat destruction, degradation, and fragmentation
Invasive species
Population growth
Pollution
Over-harvest

16. Ecological Restoration
Restoration: trying to return to a condition as similar as possible to original state.
Rehabilitation: attempting to turn a degraded ecosystem back to being functional.
Replacement: replacing a degraded ecosystem with another type of ecosystem.
Creating artificial ecosystems: such as artificial wetlands for flood reduction and sewage treatment.

17. In- Situ Leaving the animal where it lives but protecting it.
Ex. Elephants- laws prevent poaching and have people in place to enforce it.

18. Ex- Situ
Taking the animal out of its habitat & protecting it.
Ex. Zoo’s
2 types:
egg pulling -collecting wild eggs laid by critically endangered bird species and then hatching them in zoos or research centers
captive breeding- wild individuals of a critically endangered species are captured for breeding in captivity, with the aim of reintroducing the offspring into the wild.

19. Invasive Species
Many nonnative species provide us with food, medicine, and other benefits but a a few can wipe out native species, disrupt ecosystems, and cause large economic losses.

20. Protecting Biodiversity- 1972
CITIES-
Signed by 169 countries, lists 900 species that cannot be commercially traded
Banned all international trade in elephant products to protect elephant populations

22. Protecting Biodiversity- 1992
CBD- Convention on Biodiversity
Calls on nations to cooperated and establish steps of action to be taken to protect the world’s biodiversity.

23. What can you do? Adopt a forest. Plant trees and take care of them.
Recycle paper and buy recycled paper products.
Restore a nearby degraded forest or grassland.
Landscape your yard with a diversity of plants natural to the area.
Live in town because suburban sprawl reduces biodiversity
Do not buy birds, snakes, turtles, tropical fish, and other animals that are taken from the wild.