Biodiversity The number of different species in a particular area.

The Value of Biodiversity Wild organisms & ecosystems = source of beauty/recreation Wild organisms & ecosystems = source of beauty/recreation Economic value – provide things essential to human survival (food, oxygen, material for clothing, medicine, etc.) Economic value – provide things essential to human survival (food, oxygen, material for clothing, medicine, etc.)

Factors Affecting Biodiversity 1. Larger area = more species 2. Climate – warmer, wetter area (near the equator) have more diversity 3. Niche Diversity – diverse ecosystems will have more species (ex. Coral reefs) 4. Genetic Diversity 5. Extinction of Species

Genetic Diversity Healthy populations have diverse traits Healthy populations have diverse traits Individual differences make up the “gene pool” Individual differences make up the “gene pool” –Species without diversity are less able to adapt to diseases or parasites

Extinction of Species Extinction – disappearance of all members of a species from Earth Extinction – disappearance of all members of a species from Earth Endangered Species – species in danger of becoming extinct in the near future. Endangered Species – species in danger of becoming extinct in the near future. Threatened Species – Species that could become endangered Threatened Species – Species that could become endangered

Value to the Ecosystem All species in an ecosystem are connected All species in an ecosystem are connected Keystone species – influences the survival of many other species Keystone species – influences the survival of many other species –Ex. Sea stars keep the mussel population down so other species can flourish

Habitat Destruction Major cause of extinction Major cause of extinction Loss of natural habitat Loss of natural habitat –Ex. Forests cleared to build towns or create grazing land

How Do Humans Affect Biodiversity?

Habitat Fragmentation Breaking larger habitats into smaller, isolated pieces Breaking larger habitats into smaller, isolated pieces –ex. Building a road through a forest  Trees (wind damage)  Plants (issues w/ seed dispersal)  Large mammals may not find enough food

Poaching Illegal killing or removal of wildlife Illegal killing or removal of wildlife –Hunted for skin, fur, teeth, horns, or claws –Used to make medicine, jewelry, coats, etc. Some animals are sold as exotic pets Some animals are sold as exotic pets –Ex. Tropical fish and parrots

Pollution Pollutants – substances that cause pollution Pollutants – substances that cause pollution –Through air or water –May settle in soil and get absorbed by plants (pollutants then move through the food chain)

Exotic Species Introducing exotic species can threaten biodiversity. Introducing exotic species can threaten biodiversity. –Ex. Rats in Hawaii had no predators and ate the eggs of the nene goose.

Protecting Biodiversity – Captive Breeding The mating of animals in a zoo or wildlife preserves The mating of animals in a zoo or wildlife preserves Offspring released into wild Offspring released into wild Ex. Californian condor Ex. Californian condor

Laws and Treaties Endangered Species Act of 1973 – prohibits importing or trading products made from threatened or endangered species Endangered Species Act of 1973 – prohibits importing or trading products made from threatened or endangered species Convention on International Trade in Endangered Species – signed by 80 nations; protects 700 species Convention on International Trade in Endangered Species – signed by 80 nations; protects 700 species

Habitat Preservation Saves endangered species and other species that depend on them Saves endangered species and other species that depend on them –Ex. Yellowstone National Park (world’s 1 st national park) Reserves must have the characteristics of diverse ecosystems Reserves must have the characteristics of diverse ecosystems –Large, variety of niches