Biodiversity Chapter 10.1

Biodiversity Short for biological diversity, is the variety of organisms in a given area, the genetic variation within a population, the variety of species in a community, or the variety of communities in an ecosystem. Highest in areas like tropical rain forests

Unknown Biodiversity The number of species known to science is about 1.7 million, most of which are insects. True number unknown. Scientists accept an estimate of greater than 10 million.

Unknown Biodiversity

Benefits of Biodiversity Species are connected to ecosystems Species and population survival Medical, industrial, and agricultural uses Ethics, aesthetics, and recreation

Species Connected to Ecosystems Keystone Species: Species that are critical to the functioning of an ecosystem (ex: otters) because it affects the abundance and survival of many other species in its community. Ex: sea otter…less sea otter = more sea urchins = kelp gone = the loss of kelp beds along the U.S. Pacific Coast.

Species and Population Survival Genetic diversity increases the chance that some members of a species will survive environmental changes. Less genetic diversity means more genetic diseases could be inherited.

Medical, Industrial, and Agricultural Uses Organisms are used for food, clothing, shelter, and medicine throughout history About ¼ of the drugs prescribed in the US come from plants and almost all antibiotics come from chemicals found in fungi We continue to find new uses for species or chemicals in those species

Medical Uses

Human Impact on Biodiversity Endangered Species: species likely to become extinct if protective measures are not taken immediately Threatened Species: species that has a declining population that is likely to become endangered if not protected Habitat destruction/fragmentation Invasive exotic species Harvesting, hunting, poaching Pollution

Areas of Critical Biodiversity Endemic Species: species that are native to and only found in a limited area, can indicate overall biodiversity in that area Tropical Rain Forests Coral Reefs and Coastal Ecosystems Islands

Tropical Rain Forests Cover less than 7% of the Earth’s land surface, but contain over half of the world’s species Frequently cleared for farming or cattle grazing A Biodiversity hotspot: most threatened area of high species diversity on Earth

Coral Reefs and Coastal Ecosystems Occupy a small fraction of the marine environment, but contain most of its biodiversity Provide food and tourism revenue Protect coasts from waves Sources of new chemicals Threatened due to overfishing and pollution

Islands Some limited, unique species live on islands Competition can kill off these unique species

BIODIVERSITY HOTSPOTS