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Ecology

Ecology. Organisms. Organisms. Niche. It is an organisms role in the community. It includes: what it eats What eats it What and how much resources it uses Can you think of an example?. Limits on population size.

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Ecology

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  1. Ecology Organisms Organisms

  2. Niche • It is an organisms role in the community. It includes: • what it eats • What eats it • What and how much resources it uses • Can you think of an example?

  3. Limits on population size • The maximum number of individuals of a species that an area can support is called carrying capacity • Limiting factors are factors that limit a populations size • Factors can be abiotic or biotic

  4. 2,000 dN  1.0N Exponential growth dt 1,500 K  1,500 Logistic growth Population size (N) 1,000 dN 1,500  N  1.0N dt 1,500 500 0 0 5 10 15 Number of generations Population growth

  5. Limiting factors • Examples of abiotic include: • Oxygen in a pond, • amount of sunlight • Temperature • Examples of biotic factors include: • Predators • Competition

  6. Figure 53.10 Examples of terrestrial and marine food chains

  7. Figure 53.11 An antarctic marine food web

  8. Other feeding relationships • Decomposers break down dead plants and animals. • This recycles the materials • Scavengers are consumers that eat dead organisms • Parasites attack living organisms

  9. Figure 54.2 Fungi decomposing a log

  10. Figure 54.11 An idealized pyramid of net production

  11. Materials are recycled but energy is NOT • Ecosystems need a constant source of energy from the sun.

  12. Figure 54.17 The carbon cycle

  13. Biodiversity • Is the measure of how many different species there are in an area • Ecosystems that have a high biodiversity are more stable • It is valuable to humans because it can be a source of medicine. • What other benefits are there? • Name a human activity that can lead to the loss of biodiversity

  14. Loss of Biodiversity • Direct Harvesting • Habitat destruction • Deforestation • Imported Species

  15. Water Pollution • Sewage and animal wastes add nutrients to the water • This causes algae to grow more and die more • Decomposers suck oxygen out of the water • If too much oxygen is removed, the fish begin to die

  16. Toxic Wastes • Chemicals that are added to lakes and rivers can kill off many kinds of organisms • An example is DDT • Biological control

  17. Burning fossil fuels • Burning oil and coal releases CO2 and sulfur into the air • Sulfur in the air will lead to acid rain that can damage or kill plants and animals • Can cause some lakes to be so acidic that nothing can live there • CO2 is a greenhouse gas and can lead to global warming • Ice caps can melt causing a rise in sea level and loss of coastline

  18. Ozone Depletion • Ozone is found in the upper atmosphere • It absorbs much of the harmful radiation from the sun • Depletion of the ozone will allow more harmful radiation to hit the Earth • This can lead to higher mutation and cancer rates.

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