1. Biodiversity, Conservation, and Human Impact on the Environment

2. Biodiversity defined…
DEF: the variety of life in an area.
The greater the variety of species within it, the more robust an ecosystem will be.

3. Figure 50.25a Tropical forests

4. Figure 50.25c Deserts

5. Importance of Biodiversity
Beauty – aesthetic standpoint
Nature –
Orgs are adapted to live together in communities; not always clear how orgs are related, so taking away one species can have a BROAD RANGE OF EFFECTS.
The variety of lifeforms on Earth, all inter-connected to each other through food webs, makes our survival possible -- autotrophs, heterotrophs, decomposers all need one another
Biodiversity provides crucial "ecosystem services"— Ex. clean water, breathable atmosphere, and natural climate control, upon which all species depend.

6. The extermination of plant populations changes climates locally and has severe regional effects through disturbance of the water cycle.
(Remember – transpiration releases 90% of all water taken in by a plant, and the water has been filtered as it passes through the plant itself…)

7. Destruction of habitat severely limits the animal populations that can live in an area. (Threatened, Endangered, Extinction of species)

8. Figure A hundred heartbeats from extinction: Philippine eagle (left), Chinese river dolphin (right)

9. Ex. Beef, chicken, pork, fish, shellfish Ex. Penicillin came from mold
People – Food, medicine, clothing and shelter are all derived from the abundant organic resources of the Earth.
Ex. Beef, chicken, pork, fish, shellfish
Ex. Penicillin came from mold
Ex. Quinine (malaria treatment) came from bark of cinchona tree
Ex. Cotton from plant, wool from sheep, silk from worms
Ex. Wood from trees

10. Threats to Biodiversity
Habitat loss
Habitat Fragmentation (Biotic and Abiotic issues)
Habitat degradation caused by
air pollution, water pollution,
land pollution
Introduction of Exotic Species

11. Habitat loss… Biggest threat to biodiversity
When area to live is gone, orgs die
Ex. deforestation

12. Figure 55.0 Deforestation of tropical forests

13. Figure 55.00x Deforestation in the United States

14. Habitat Fragmentation
Separation of wilderness areas from other wilderness areas
Fragmented areas are like islands; the smaller the fragment, the less biodiversity it will support

15. Figure 55.5 Fragmentation of a forest ecosystem

16. Figure 55.6 The history of habitat reduction and fragmentation in a Wisconsin forest

17. Biotic and Abiotic Issues of Fragmentation
-some organisms need large areas to gather food
Ex. Lions
Ex. Zebra
-no migratory routes to re-establish populations lost due to natural disasters
Abiotic:
-climate can change
-can cause EDGE EFFECT
(different conditions along the boundaries of an ecosystem)

18. Habitat Degradation Damage to habitat by pollution
Three types of pollution: air, water, land

19. Air pollution breathing problems irritation of membranes
Burning of fossil fuels is biggest source
Ozone layer is being broken down by CFC’s (carbofluorocarbons) – found in refrigerators and air conditioners as coolants; this allows radiation to reach earth, causing genetic defects and cancer

20. Figure 54.27a Erosion of Earth’s ozone shield: The ozone hole over the Antarctic

21. Water Pollution
Degrades aquatic habitats in streams, lakes, and oceans
Excess fertilizers and animal waste get into streams and cause algal blooms
Coral reefs are destroyed when silt covers the living coral and they can’t photosynthesize or get to food
Detergents, heavy metals, and industrial chemicals in runoff cause sickness and death in aquatic orgs
Abandoned drift nets trap dolphins, whales, fish, sea turtles
Acid precipitation is responsible for deterioration of forests and lakes, also damages plant tissues and interferes with plant growth.
(sulfur dioxide from coal-burning factories and nitrogen oxides from exhausts combine with water vapor to form acid droplets of water vapor)
Use of pesticides such as DDT – gets into water

22. Figure 54.25 Biological magnification of DDT in a food chain

23. Silent Spring Figure 50.3 Rachel Carson Biologist, Writer, Ecologist
"The more clearly we can focus our attention on the wonders and realities of the universe about us, the less taste we shall have for destruction."
-- Rachel Carson © 1954
Silent Spring

24. Land Pollution Trash – solid waste
Made up of cans, bottles, paper, plastic, metals, dirt, spoiled food, etc.
Average American produces 1.8 kg of waste daily
Landfills take up space

25. Introduction of Exotic Species
New orgs introduced into an ecosystem; do not have any natural predators and is little competition with other orgs, so native species are at risk
Exotics may take over niches of native species and eventually replace the native species completely

26. Greenhouse Effect and Global Warming
In 1996, the United States was responsible for 23% of the world’s carbon dioxide emissions -- more than any other country.
Carbon dioxide is the primary greenhouse gas, responsible for 60 % of global warming

27. Extinction Rates
Extinction has usually progressed at what scientists call a natural or background rate. Today the tempo is far faster.
Many scientists believe this is the sixth great wave - the sixth mass extinction to affect life on Earth.
We (humans) have more than doubled our numbers in half a century, and that is the most obvious reason why there is less room for any other species.
We are taking their living room to grow our food, their food to feed ourselves.
We are exploiting them, trading in them, squeezing them to the margins of existence - and beyond.

28. Conservation efforts:
Conservation Biology: studies methods and implements plans to protect biodiversity
*legal protection of species
*habitat preservation
(sustainable use,
habitat corridors)
*reintroduction programs

29. How can we prevent biodiversity loss?
Research
Legislation
Education/Awareness
Sustainable use of habitats and fisheries
Integration/Co-ordination

30. What can you do? Be aware… Reuse and recycle Turn off water and lights
Carpool
Vote responsibly
Volunteer
Be the teacher!