1. Biodiversity

2. Biodiversity
Biological diversity or “Biodiversity” = the sum total of the genetically based variety of all organisms in the biosphere
Our existence relies on a great variety of other organisms.
Some branches within biodiversity:
Ecosystem diversity = variety of habitats, communities, and ecological processes in the ecosystem
Species diversity = number of different species in the system
Genetic diversity = sum total of all the different forms of genetic information carried by all organisms present

3. Species Diversity Insects Protists Other Animals Plants Bacteria Fungi
Section 6-3
Insects
54.4%
Protists
Other Animals
4.2%
19.7%
Plants
18%
Bacteria
Fungi
0.3%
3.4%
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4. Value of Biodiversity
Biodiversity is one of Earth’s greatest natural resources providing us with food, industrial products, and medicines (painkillers, antibiotics, heart drugs, antidepressants, and anticancer drugs)
When biodiversity is lost, potential sources of material with significant value to the biosphere and to humankind may be lost.
Think of biodiversity as a library- lost species are essentially lost books that can’t be replaced.

5. Threats to Biodiversity
Human activities can reduce biodiversity by:
Habitat alteration
Hunting species to extinction
Extinction = occurs when a species disappears from all or part of its range
Endangered species = species in danger of extinction with declining population sizes
As the population declines, the species loses genetic diversity, making it more vulnerable to extinction
Introducing toxic compounds (pollutants) into food webs
Introducing foreign species to new environments

6. Habitat Alteration & Fragmentation
When land is developed, natural habitats may be destroyed and the species that live in those habitats may vanish
Habitat fragmentation = development of land that splits ecosystems into pieces resulting in biological “islands” with fewer species and smaller populations more vulnerable to further disturbances or climate changes
Reduces habitat space
Restricts movement
Reduces diversity

7. Fragmentation

8. Hunting/Wildlife Products
In the past, hunting for meat, fur, hides or other body parts caused the extinction of some species
Today, endangered species are protected from hunting by laws in most of the world
Endangered Species- species in danger of going extinct. Protected by international and local laws
Poaching is still a major problem
Bear gall bladders, ivory, shark fins, tiger bones, etc.

9. Pollution
Pollution can threaten biodiversity, because toxic compounds accumulate in tissue of organisms
Toxic wastes, sedimentation, thermal pollution
Biological magnification = increasing concentrations of harmful substances in organisms at higher trophic levels in a food chain/web
Entire food web is affected, but top-level carnivores are at highest risk

10. Biological Magnification of DDT
Section 6-3
Magnification of
DDT Concentration
Fish-Eating Birds
10,000,000
Large
Fish
1,000,000
100,000
Small Fish
10,000
Zooplankton
1000
Producers
Water 1
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11. Thermal Pollution
Thermal pollution: is the degradation of water quality by any process that changes ambient water temperature
Power plants and industry using local water supplies to cool during manufacturing.
The temperature of the discharge water is significantly warmer than normal
Warmer water holds less
Oxygen, supports less life

12. Introducing Foreign Species
Biodiversity is also threatened by apparently harmless plants and animals that humans transport around the world either accidentally or intentionally
Invasive species = organisms introduced into new habitats and reproduce rapidly (think exponential) lacking the parasites and predators that control population size in their native country
They can displace native species driving them close to extinction
Ex. Zebra Mussels

13. Invasive species Non-native species kudzu
reduce diversity in ecosystem
examples
African honeybee (killer bees)
gypsy moth
zebra mussel
purple loosestrife
Phragmites
gypsy moth
phragmites
kudzu

14. Purple loosestrife reduces diversity
1968
1978
reduces diversity
loss of food & nesting sites for animals

15. Zebra mussel reduces diversity
~2 months
ecological & economic damage
reduces diversity
loss of food & nesting sites for animals
economic damage

16. Brown Tree Snakes, Guam
This introduced snake has caused the extinction on Guam of 12 of 14 forest bird species, two of three bat species, and at least six lizard species.
Grow up to 8-10 feet long.
Hatch at 15 inches can grow to 3 feet in one year

17. Guam Bird Populations

18. Conserving Biodiversity
Conservation = wise management of natural resources
Preservation of habitats and wildlife to protect Earth’s biodiversity for future generations, however protected areas may not be enough
Current conservation efforts focus on protecting individual species as well as entire ecosystems (to ensure natural habitats and interactions among different species are preserved).
“Hot spots” = places around the world where everything possible is being done to conserve the ecosystem and species

19. World Wide Hotspots