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.

What is Biodiversity?

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

Why is biodiversity important?

“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”

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.

http://en.wikipedia.org/wiki/File:Lacanja_burn.JPG

Invasive / Exotic Species

Invasive, exotic species introduced from elsewhere outcompete native species because they:Have no natural predatorsColonize disturbed habitats quicklyHave a high biotic potential (r-species)

http://en.wikipedia.org/wiki/File:Kudzu_on_trees_in_Atlanta,_Georgia.jpg

http://en.wikipedia.org/wiki/File:Bufo_marinus_from_Australia.JPG

Cane Toads – The Conquest movie

Pollution

Pollution (Oil spills, human agricultural waste, fertilization, pesticides, acid

deposition, greenhouse gases etc) caused by human activities has a negative effect on

biodiversity

http://en.wikipedia.org/wiki/File:AlfedPalmersmokestacks.jpg

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.

http://en.wikipedia.org/wiki/File:World_population.svg

Overharvesting, Overuse, Overexploitation

Overhunting, overfishing, destructive harvesting practices (cyanide,

dynamite), illegal trade, exotic pet industry

http://en.wikipedia.org/wiki/File:Fishing_down_the_food_web.jpg

HumanPopulation

Increase

IncreasingEconomic

Activity

Increased use of technology

Social, politicaland cultural

factors

Land use change(Habitat loss)

IncreasingEconomic

Activity

Increased use of technology

Social, politicaland cultural

factors

Indirect (Underlying

causes)

Directcauses

DecliningBiological Diversity

Raven, Berg, and Hassenzahl put it this way

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 habitsSpecialized nesting and/or breeding areasFixed migratory patternsFound in one place or region

• Rare • Commercially valuable• Negative human interactions including

attacks on people or livestock

How can humanity protect

biodiversity?

http://en.wikipedia.org/wiki/File:Siproeta_epaphus_Galawebdesign.jpg

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

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 2100. 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

http://en.wikipedia.org/wiki/File:MEAConservationStrategies.jpg

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.