Biodiversity

Directions: Copy only the underline words or paragraphs. Do not forget the headings or subheadings Use ISN pages 98, 99 and 100

Essential Questions 1. List and describe the three levels of biodiversity on earth. 2. Describe several ways biodiversity is being threatened on Earth. 3. Explain the advantages of protecting an entire ecosystem instead of a single species.

Biodiversity is short for Biological diversity means the number of different species in a given area. We have catalogued over 1.7 million different species on earth, with most of them being insects. Scientists estimate there is over 10 million species on earth.

The Three Levels of Biodiversity Species Genetic Ecosystem Species diversity refers to the number of different species in an area. Ecosystem diversity refers to the variety of habitats, communities, and ecological processes within and between ecosystems. Genetic diversity refers to all the different genes contained within all members of the population.

Benefits of Biodiversity Connected Healthy ecosystems have healthy species. Keystone species are species critical to the functioning of an ecosystem. Survival Genetic diversity increases the chances that some members of a species will survive environmental changes. Small and isolated populations are less likely to survive such changes. Uses We use organisms for food, clothing, shelter and medicine. Undiscovered and unstudied species are a source of potential products.

Keystone Species A keystone species is a species that is critical to the functioning of an environment. An example of a keystone species is the sea otter. Sea otters eat sea urchin, sea urchin eat kelp. The loss of the sea otter population led to the loss of kelp beds along the US Pacific coast. The recovery of the sea otters led to the recovery of the kelp populations.

Biodiversity at Risk 65 million years ago, a series of changes in the Earth’s climate and ecosystems caused the extinction of about half the species on Earth, The extinction of many species in a relatively short period of time is called a mass extinction. It takes millions of years for biodiversity to rebound after a mass extinction.

Current Extinctions Scientists are warning that we are in the midst of another mass extinction. The rate of extinction is estimated to have increased by 50x since 1800. Between 1900 and 2100, up to 25 percent of all species on Earth may become extinct. Humans and human activity is the primary cause of the extinction.

Cockroaches and rats have large populations and will not become extinct. They adapt to many habitats easily. Species at risk are those that migrate, need large or special habitats or are exploited by humans. Endangered Species A species that is likely to become extinct if protective measures are not taken immediately. Threatened Species A species that has a declining population and that is likely to become endangered if not protected.

How do humans cause Extinctions? Habitat Destruction and Fragmentation Population -> more homes and food needed Florida Panthers and Cougars Invasive Exotic Species A species not native to a particular region. FIRE ANTS!!!!! Harvesting, Hunting and Poaching Passenger pigeons and bison Pollution Pesticides, cleaning agents, drugs and other chemicals are making their way into food webs all over the world. BALD EAGLE!

Areas of critical biodiversity Some parts of the world contain a greater diversity of species than others. These areas have endemic species, meaning species that are native to and found only within a limited area. Ecologists use plants as an indicator of overall biodiversity because plants form the basis of ecosystems on land. Earth’s various organisms appear to be concentrated in certain biomes.

Tropical Rain Forests The greatest loss of diversity happens in the tropical rainforests. The remaining tropical rainforests only cover about 7% of the Earth’s land surface. Biologists estimate that over half of the world’s species live in these forests. Unknown numbers of species are disappearing as tropical forests are cleared for farming and cattle grazing.

Coral Reefs and Coastal Ecosystems Coral reefs occupy a small fraction of the marine environment yet contain the majority of the diversity there. Reefs provide millions of people with food and tourism revenue. 60% of coral reefs are threatened by overfishing and pollution. Coastal areas are routes for many migrating species as well as links to ecosystems on land.

Islands When an island rises from the sea, it is colonized by a limited number of species from the mainland. Colonizing species often evolve into several new species. Hawaii have 28 species of an endemic family of birds called honeycreepers. Honeycreepers are endangered by competition from exotic species.

Biodiversity Hotspots Hotspots are the most threatened areas of high species diversity. These are areas that have high numbers of endemic species but are also threatened by human activities. Most hotspots have lost 70% of their original plants and include tropical rainforests, coastal areas, and islands. In Madagascar, only 18% of the original forests remain.

Biodiversity in the United States The US has a wide variety of ecosystems, including the Florida Everglades, the California coastal region and Hawaii. The US holds unusually high numbers of species of freshwater fish, mussels, snails, and crayfish. Land plants also have a high diversity rate with pine trees and sunflowers. The California Floristic Province, a hotspot, is home to 2,124 endemic and 565 threatened and endangered species.

The Future of Biodiversity Captive Breeding Programs Captive breeding programs involve breeding animals in captivity, with the hope of reintroducing populations to their natural habitats. Example: California Condor Habitat loss, poaching and lead poisoning almost killed every condor. 121 were released into the wild but the survival is still doubtful.

Preserving Genetic Material One way to save the essence of a species is by preserving its genetic material. Germ plasm is any form of genetic material, such as that contained within the reproductive or germ cells of plants and animals. Germ plasm banks store germ plasm for future use in research or species recovery efforts.

Zoos, Aquariums, Parks and Gardens The original idea of zoos was to put exotic animals on display. Now zoos display the few remaining members of a species. They are living museums of the world’s diversity.

Preserving Habitats and Ecosystems The most effective way to save species is to protect their habitats. Most of the time it takes large areas of land to do this. Most conservationists now give priority to protecting entire ecosystems rather than individual species. By protecting the entire ecosystem, we may be able to save most of the species in an ecosystem instead of just one.

Legal Protection for Species US Laws: Are considered to be the strongest in the world. Endangered Species Act, 1973. is designed to protect plant and animal species in danger if extinction. As of 2005, 1,272 species of plants and animals were listed as endangered or threatened. Reintroducing the gray wolf in certain areas of the northwestern US is in accordance with the Act. It also says anyone who harms, buys or sells any part of these species are subject to a fine. Third part prevents the government from carrying out any project that jeopardizes a listed species.

Recovery and Habitat Conservation Plans Under the Endangered species Act the last thing they must have is a species recovery plan for each listed species. These plans often propose to protect or restore habitat for a species. A habitat conservation plan – a plan that attempts to protect one or more species across large areas of land through trade-offs or cooperative agreements. They can also have a permit to capture and conduct research with an endangered species.

International Cooperation At the global level, the International Union for the Conservation of Nature and Natural Resources (IUCN) facilitates efforts to protect species and habitats. It is a collaboration of about 200 governmental agencies and 700 private conservation group from around the world. An international treaty, The Convention on International Trades in Endangered Species (CITES) was the first effective effort to stop the slaughter of African elephants. It stopped the sale of ivory world-wide and stopped much of the poaching of ivory tusks.

The Biodiversity Treaty One of the most ambitious efforts to tackle environmental issues was the United Nations Conference on Environment and Development, also known as the Earth Summit. The Biodiversity Treaty was developed at this conference. The treaty's goal is to preserve biodiversity and ensure the sustainable and fair use of genetic resources in all countries. The World Wildlife Fund encourages the sustainable use of resources and supports the wildlife protection.