1 / 23

CHAPTER 5

CHAPTER 5. BIODIVERSITY AND CONSERVATION. BIODIVERSITY MAIN IDEA: Biodiversity maintains a healthy biosphere and provides direct and indirect value to humans. WHAT IS BIODIVERSITY?

litchfield
Télécharger la présentation

CHAPTER 5

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CHAPTER 5 BIODIVERSITY AND CONSERVATION

  2. BIODIVERSITY • MAIN IDEA: Biodiversity maintains a healthy biosphere and provides direct and indirect value to humans. • WHAT IS BIODIVERSITY? • Biodiversity is the variety of life in an area that is determined by the number of different species in that area. • Biodiversity increases the stability of an ecosystem and contributes to the health of the biosphere. • There are 3 types of biodiversity: • Genetic diversity • Species diversity • Ecosystem diversity • Extinction is when the last member of the species dies.

  3. GENETIC DIVERSITY • Genetic diversity is the variety of genes or inheritable characteristics that are present in a population. • Genetic diversity within interbreeding populations increases the chances that some individuals will survive during changing environmental conditions or during an outbreak of disease.

  4. QUESTION: In the picture below, what are some of the different heritable characteristics that you see and how could some of those differences be helpful?

  5. SPECIES DIVERSITY: • Species diversity is the number of different species and the relative abundance of each species in the a biological community. • Species diversity is not evenly distributed over the biosphere. • Species diversity increases as you move further away from the poles & closer to the equator.

  6. QUESTION: In the picture below how many different species are present?

  7. ECOSYSTEM DIVERSITY • Ecosystem diversity is the variety of ecosystems that are present in the biosphere. • Ecosystems are made up of interacting populations and the abiotic factors that support them.

  8. THE IMPORTANCE OF BIODIVERSITY • DIRECT ECONOMIC VALUE • Direct economic value for maintaining biodiversity include: • Food • Need diverse genetic pools to help keep the food source safe from the effects of devastating diseases or insects. • Done through genetic engineering when scientists transfer genes from one organism to another • Clothing • Energy • Medicine • Mostly produced from plants or other organisms. • EX: Madagascar periwinkle flower yields an extract to treat some forms of leukemia increasing survival rate from 20% to more than 95%. • Shelter

  9. INDIRECT ECONOMIC VALUE • Healthy biosphere provides many services to humans and other organisms. • Plants provide oxygen & remove carbon dioxide • Safe water for drinking • Cycling nutrients • Provide protection against floods and droughts • Preserve fertile soils • Detoxify and decompose wastes and regulate local climates

  10. SECTION 2 – THREATS TO BIODIVERSITY • MAIN IDEA: Some human activities reduce biodiversity in ecosystems, and current evidence suggests that reduced biodiversity might have serious long term effects on the biosphere. • QUESTION: What happens when a new building project starts in an area that was previously undeveloped?

  11. EXTINCTION RATES • Background extinction is the gradual process of species becoming extinct. • Occurs when stable ecosystems are changed by: other organisms, climate changes, or natural disasters • Predicted that 1/3 to 2/3 of all plant & animal species, mostly near the equator, will become extinct during 2nd half of this century. • Mass extinction is events where a large percentage of all living species become extinct in a relatively short period of time. • Last one was 65 million years ago for dinosaurs • Large percentage of extinctions take place on islands • Small populations • Affected by newly introduced predators, can’t escape island, nonnative species, and disease

  12. FACTORS THAT THREATEN BIODIVERSITY • Natural resources are all materials and organisms found in the biosphere, including minerals, fossil fuels, nuclear fuels, plants, animals, soil, clean water, clear air, and solar energy.

  13. OVEREXPLOITATION • Overexploitation is the over use of species that have economic value, which increases their current rate of extinction • EX: N. American bison • Previously overexploitation was the primary cause of species extinction, NOW it is the destruction of habitat.

  14. HABITAT LOSS • Habitat loss is the result of: • Destruction of habitat • Tropical rain forest contains more than half of all species on Earth • Clearing the tropical rain forest for agricultural crops or grazing land reduces habitat & species • Disruption of habitat • Fig. 11, Pg. 125 shows how the # of harbor seals & sea lions declined, setting off the chain reaction of what the whales ate (now more sea otters), which normally ate the sea urchins, now their population is up & the kelp is way down.

  15. FRAGMENTATION OF HABITAT • Habitat fragmentation is the separation of an ecosystem into small pieces of land • Populations will stay in the small parcels because they are either unable or unwilling to cross the human-made barriers. • Problems: • Smaller the land means fewer species that are supported • Reduces opportunities for individuals in one area to reproduce with individuals from another area • Genetic diversity decreases over time causing populations to become less resistant to disease, or able to respond to changing environmental conditions. • Creates edge effects, which is when boundaries of the ecosystem have different abiotic factors like temperature, wind & humidity than the rest of ecosystem.

  16. POLLUTION • Pollution changes the composition of air, soil and water. • Pesticides • DDT – enters food chain & remains in tissues of organisms • Industrial chemical • PCB – enters food chain & remains in tissues of organisms • Biological magnification is the increasing concentration of toxic substances in organisms as trophic levels increase in a food chain or web. • Higher level carnivores are most affected • EX: Bald eagle – caused the thinning of the egg shells so no new eagles were being born

  17. POLLUTION – CONTINUED • Acid precipitation is created when fossil fuels are burned releasing sulfur dioxide and nitrogen oxides into the atmosphere. • Reaction with water & other substances in the air create sulfuric acid & nitric acid • Will remove calcium, potassium and other nutrients from soil • Will damage plant tissues & slows their growth or kills • Eutrophication occurs when fertilizers, animal waste, sewage, or other substances rich in nitrogen and phosphorus flow into water, crease extensive algae growth • Algae will use up the oxygen supply causing other organisms to suffocate

  18. INTRODUCED SPECIES • Introduced species are nonnative species that are either intentionally or unintentionally transported to a new habitat. • Reproduce rapidly because there are no predators, parasites and competition to keep them controlled in the new environment. • Now considered an invasive species • EX: Fire ants • Invasive species believe to be responsible for 40% of the extinctions since 1750

  19. SECTION 3 – CONSERVING BIODIVERSITY • MAIN IDEA – People are using many approaches to slow the rate of extinctions and to preserve biodiversity. • NATURAL RESOURCES • Natural resources are used to meet our basic needs • Industrialized countries use more natural resources per person than developing countries • 2 types of natural resources: • Renewable • Nonrenewable

  20. RENEWABLE RESOURCES • Renewable resources are any resources that is replaced by natural processes faster than they are consumed • EX: solar energy, agriculture, plants, animals, clean water and air • These resources are NOT unlimited. • Any resource can be depleted. If depleted, natural resource would change from renewable to nonrenewable. • EX: Removing a few trees = renewable resource Removing a whole forest = nonrenewable resource

  21. NONRENEWABLE RESOURCE • Nonrenewable resources are found on Earth in limited amounts or that are replaced by natural processes over extremely long period of time. • EX: fossil fuels and minerals deposits • Species are considered nonrenewable when extinction occurs because now it is lost forever • SUSTAINABLE USE • Sustainable use happens when we use the resources at a rate where they can be replaced or recycled them while preserving the long-term environmental health of the biosphere. • Conservation of resources happens when we reduce the amount of resources that are consumed, recycled resources (aluminum cans) occurs, and we preserve and use ecosystems in a responsible manner.

  22. PROTECTING BIODIVERSITY • US helps protect biodiversity by establishing national parks & nature reserves • EX: 1st national park – Yellowstone in 1872 • Currently 7% of the world’s land is set aside as a natural reserve, some of them megareserves • To be classified as a biodiversity hot spot the region must have lost at least 70% of the original habitat and there must be at least 1500 species of plants that are endemic (species found only in specific geographic areas with critical levels of habitat loss) • Hot spots shown on pg. 132 • To improve the survival of biodiversity conservationists are developing corridors or passageways to connect small parcels of land allowing the organisms to move from one area to another safely.

  23. RESTORING ECOSYSTEMS • Biodiversity is destroyed in an area when it no longer provides the abiotic and biotic factors needed for a healthy ecosystem. • EX: clearing tropical rain forest for farming & then is unproductive after a few years. • Recovery from human or natural disasters can happen, but depends on size of the area affected and the type of disturbance. • Larger the area = longer time

More Related