1. Biodiversity General information Importance of biodiversity
Threats to biodiversity
Preserving biodiversity

2. General information
Biodiversity refers to the variety of species in a specific area
The most common measure of biodiversity is the number of species living in that area
Biodiversity varies from place to place on Earth
biodiversity increases from the poles to the equator
more stable conditions allow more specialization, and thus more species

3. General information
A recent study (Aug 2011) estimated that Earth had to 10.0 million species
80% of species are animals, 20% plants, fungi, protozoa
86% of land species and 91% of ocean species have yet to be discovered

4. Importance of biodiversity
Biodiversity provides stability to ecosystems

5. Importance of biodiversity
A single species can be critical to an ecosystem
A “keystone” species
Pacific coast sea otters
Lived in kelp beds, eating shellfish and sea urchins
Hunted throughout the 1800s for fur
Reduction in sea otters allowed sea urchins to multiply, eating kelp anchors, destroying habitat
In 1937, surviving otters were discovered, with protection their population rebounded, sea urchin population was reduced, kelp beds re-established

6. Importance of biodiversity
Biodiversity provides resources for future
Nearly 40% of prescription drugs originated with living things – mainly from plants
Vinblastine – rosy periwinkle – leukemia
L-dopa – velvet bean – Parkinson’s disease
Future foods may come from unknown plants
World relies on three crops – corn, wheat, rice
Vulnerable to diseases/pests – Ireland’s potato crop affected by fungus in 1840s, 2 million died

7. Threats to biodiversity
The most common reason for decline in biodiversity (for accelerated extinction) is habitat destruction as humans use more land

8. Threats to biodiversity
Habitat fragmentation – breaking up large habitat areas into smaller areas –also disrupts ecosystems, reducing biodiversity

9. Threats to biodiversity
Biodiversity can also be threatened by habitat degradation (damage to a habitat by pollution)
Air pollution can contribute to acid precipitation
Water pollution from excess nutrients can cause algal blooms and subsequent loss of dissolved oxygen
Land pollution from pesticides and other chemicals can disrupt food webs

10. Threats to biodiversity
Exotic species – species introduced to areas in which they are not native
Lacking natural predators, exotic species out- compete native ones
Silver carp
Snake head fish
Kudzu

11. Preserving biodiversity
The Endangered Species Act
Endangered species – a species whose population is so low that extinction is possible if not protected
Threatened species – a species that could become endangered if not protected
Preservation of habitat has been found to be the best approach to protecting endangered and threatened species
Conflict between human and wildlife needs can occur and are often very controversial

12. Preserving biodiversity
Captive-breeding programs
Some animals have responded to programs that breed them in zoos and wild-animal parks
Best example – the California condor
Botanical gardens and seed banks
Plants, which are not affected by “captivity”, are easily preserved in gardens and seed banks
Biodiversity “hotspots”
Areas with unusually large numbers of species
Recommended as focus of ecosystem conservation