Biodiversity

Estimate over 1.5 million species Biodiversity is the number of different species in an area. Major environmental issue. Why?

Value of Biodiversity Economic Value They can provide food, materials for clothing, medicine, and other products. Useful species still undiscovered. Ecotourism provides jobs and money for many countries

Ecological Value  All species in an ecosystem share resources and are dependent on each other for food and shelter. Some species are the center stone of their ecosystem. These keystone species are species that influence the survival of many other species in an ecosystem 1800 sea otter extinction

Factors Affecting Biodiversity Area  The larger the area the more species can be found (100 vs. 10)  

Climate Species increase from the poles toward the equator. Tropical rain forests are near the equator. Make up 7% of land mass but contain more than half the species in the world. Coral reef which are 1% of the ocean but have 20% of sea species. Due to the constant warm temperature. This allows niche diversity, where species don’t have to compete as much.

Gene Pool Diversity Genes carry organism’s hereditary information Each organism has different genes from other individuals. Individual differences make up the total gene pool. Less diversity=less ability to adapt to changes in the environment

Extinction of species Extinction is the disappearance of all members of a species from the Earth. Rate of extinction has dramatically increased. Once the size of a species drops to a certain level they may not recover.

Species in danger of becoming extinct are endangered species. Species that could become endangered in the future are called threatened species.

Causes of Extinction Habitat Destruction Habitat fragmentation (breaking large habitats into smaller ones)

Poaching Illegal killing or removal of wildlife species Hunted for their skin, fur, teeth, horns, etc Sold as exotic pets Pollution This can pollute the water or air killing animals or cause a low birth rate.

Exotic Species Introducing exotic species into an ecosystem can threaten biodiversity. Can outcompete or prey on existing species.

Protecting Biodiversity Captive Breeding Mating animals in the zoo or wildlife preserves. Scientist care for the young and release them into the wild Laws and Treaties Endangered Species Act prohibits the killing or trading of endangered animals and/or products Hard to enforce

Habitat Preservation The most effective way is to preserve a whole ecosystem. Must be large enough to preserve the population, contain a variety of niches, and be a diverse ecosystem