1. What is Biodiversity?
Biodiversity is the variety or richness of life at all structural levels (molecular/genetic, species, ecosystem). It is an essential renewable resource. It is exploited and depleted as a result of the “Tragedy of the Commons” phenomenon. The current rate of biodiversity loss is comparable to previous extinction events.

2. Why is biodiversity important?
Biodiversity provides us with:
Natural Resources (food, water, wood,
energy, and medicines)
Natural (Ecosystem) Services including: air and water purification, soil fertility, waste disposal, pest control)
Aesthetic pleasure

3. H Habitat loss, including that caused by human-induced climate change.
“The decline of Earth’s biodiversity is an unintended consequence of multiple factors that have been enhanced by human activity. They can be summarized by the acronym HIPPO, with the order of the letters corresponding to their rank in destructiveness.”
H Habitat loss, including that caused by human-induced climate change.
I Invasive species (harmful aliens, including predators, diseases, and competitors that displace native species
P Pollution
P Population, Human overpopulation to be exact, a root cause of the other four factors
O Overharvesting, Overuse (hunting,
fishing, gathering)
E. O. Wilson “The Creation”

4. Habitat loss/destruction
Habitat loss is the greatest
reason for biodiversity loss.
Habitat loss is due to:
Conversion of natural areas to farms, houses, etc
Fragmentation of ecosystems by human activities, housing, transportation, agriculture etc.
Simplification of genetic diversity and complex ecosystems by planting/selecting monocultures.

5. Invasive / Exotic Species
Invasive, exotic species introduced from elsewhere outcompete native species because they:
Have no natural predators
Colonize disturbed habitats quickly
Have a high biotic potential (r-species)

6. Cane Toads – The Conquest movie
Cane Toads – The Conquest movie

7. Pollution
Pollution (Oil spills, human agricultural waste, fertilization, pesticides, acid deposition, greenhouse gases etc) caused by human activities has a negative effect on biodiversity

8. Population, Human overpopulation that is.
6.8 Billion and counting. The expansion of human population and affluence, especially in the developing world harms natural ecosystems.

9. Overharvesting, Overuse, Overexploitation
Overhunting, overfishing, destructive harvesting practices (cyanide, dynamite), illegal trade, exotic pet industry

10. Raven, Berg, and Hassenzahl put it this way
Human
Population
Increase
Land use change
(Habitat loss)
Increasing
Economic
Activity
Increasing
Economic
Activity
Declining
Biological
Diversity
Increased use
of technology
Increased use
of technology
Social, political
and cultural
factors
Social, political
and cultural
factors
Indirect
(Underlying
causes)
Direct
causes

11. Characteristics shared by many endangered species include:
Low reproductive rate (biotic potential)
Feed at high trophic levels (apex predator)
Large body size
Specialist
Specialized feeding habits
Specialized nesting and/or breeding areas
Fixed migratory patterns
Found in one place or region
Rare
Commercially valuable
Negative human interactions including attacks on people or livestock

12. How can humanity protect biodiversity?

13. Important Laws Protecting Biodiversity
Lacey Act (1900) forbids interstate commerce of illegally killed wildlife. Modifications of act prevent importing dangerous non-native species.
Endangered Species Act (ESA) of 1973 makes it illegal to
kill, trap, uproot (plants), modify the habitat of, or engage in
commerce of an endangered species or its parts.
To designate a species as endangered or threatened, Fish
and Wildlife Service or National Oceanic and Atmospheric
Administration must:
List species
Designate critical habitat areas where species is found
Develop a recovery plan to help species survive and thrive

14. The rich variety of the natural world that Charles Darwin memorably imagined as an "entangled bank", and that E. O. Wilson labeled "biodiversity", is in crisis. The International Union for Conservation of Nature (IUCN) calculates that one-fifth of mammals and nearly one-third of amphibians are threatened with extinction. Some estimate that only half of the species alive today will survive to Others describe the pace of biodiversity loss as 100 times the rate of natural extinctions. Less-diverse ecosystems are less productive, less stable and less robust. So loss of biodiversity may weaken ecosystems and make them more fragile, especially in the face of climate change, with grave consequences for food security, among other things.
Sara Abdulla, Chief Commissioning Editor, Nature
March 2010

16. This summary of the relative effects by the year 2100 is a composite derived from calculations carried out for 12 individual terrestrial and freshwater ecosystems by O. E. Sala et al. (Science287, 1770–1774; 2000). Overall, changes in land use constitute the main estimated impact on biodiversity, but the pattern varies considerably for different ecosystems. According to Sala and colleagues' calculations, climate change will have the strongest effect on Arctic, alpine and boreal ecosystems, whereas biotic exchange (that is, invasion by non-native species) will exert its main influence in lakes.