ecology n.
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  1. Ecology

  2. What is ecology? • Ecology is the study of the interactions of living organisms with one another and with their physical environment (soil, water, climate…) • ECO = • LOGY = house the study of

  3. LEVELS OF ORGANIZATION Species Population Community Ecosystem Biome Biosphere

  4. Biosphere • The biosphere contains the combined portions of the planet in which all of life exists, including land, water and atmosphere.

  5. Energy Flow

  6. ENERGY FLOW • Every organism needs… …ENERGY!!!

  7. ENERGY FLOW • What are autotrophs? • Organisms that capture energy from the sun or chemicals to produce their own food.

  8. ENERGY FLOW • What is a producer? • Organisms that first capture energy (Autotrophs) • FIRST TROPHIC LEVEL

  9. ENERGY FLOW • During photosynthesis, autotrophs use light energy to power chemical reactions that convert CO2 and water into oxygen and high energy sugars (glucose).

  10. PRODUCERS LAND: Plants UPPER LAYERS OF OCEAN: Algae TIDAL FLATS/SALT MARSHES: Photosynthetic bacteria / cyanobacteria

  11. CHEMOSYNTHESIS • Chemosynthesis is the process by which organisms use CHEMICAL energy to PRODUCE carbohydrates. • Making food without sunlight! • Example: Bacteria

  12. ENERGY FLOW • If AUTOTROPHS are called PRODUCERS, because they make their own food, what are HETEROTROPHS called?

  13. CONSUMERS • Organisms that consume plants or other organisms to obtain energy. • All organisms that are NOT producers!!! (Heterotrophs) • Three categories • Primary • Secondary • Tertiary

  14. PRIMARY CONSUMERS • Herbivores • Eat plants or other primary producers • Examples • Cows • Horses • Rabbits • Some Insects • SECOND TROPHIC LEVEL

  15. SECONDARY CONSUMERS • Carnivores • Animals that eat animals • Examples: tigers, wolves, snakes • Omnivores • Animals that are herbivores and carnivores • Examples: bears, humans • THIRD TROPHIC LEVEL

  16. TERTIARY CONSUMERS • Carnivores that consume other carnivores • Known as “top carnivores” • Example: • A hawk that eats a snake • A lion that eats a hyena • FOURTH TROPHIC LEVEL

  17. DETRITOVORES • Decomposes organic material and returns the nutrients to the soil, water and air (making it available for other organisms). • Examples: mites, earthworms, snails, crabs

  18. DECOMPOSERS • Break down and absorb nutrients from dead organisms • They cause decay • Decomposition of bodies and wastes releases nutrients back into the environment to be recycled by other organisms. • Examples: bacteria, fungi

  19. SCAVENGERS • Do not kill their food—they search for a source of food that is already dead • “Clean-up” the ecosystem • Examples: buzzards

  20. FEEDING RELATIONSHIPS • Energy flows through an ecosystem in ONE direction: Sun (or inorganic chemicals) Autotrophs/Producers Heterotrophs/Consumers

  21. FOOD CHAIN • A food chain is a series of steps in which organisms transfer energy by eating or being eaten. • It is how energy moves through an ecosystem!

  22. FOOD WEB • A food web is a network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem.

  23. FOOD CHAIN vs. FOOD WEB • A food web will link together all of the food chains in a particular ecosystem…

  24. A terrestrial food chain A marine food chain

  25. TROPHIC LEVELS • A trophic level is a step in a food chain or food web. • Different organisms are on different levels depending on their source of energy. • Where does energy come from? SUN


  27. TROPHIC LEVELS • A consumer in a food chain depends on the trophic level below it for energy.

  28. Ecological Pyramids

  29. ECOLOGICAL PYRAMIDS • An ecological pyramid is a diagram that show the relative amounts of energy or matter contained within each trophic level of a food chain or food web.

  30. ECOLOGICAL PYRAMIDS • Only part of the energy stored in a trophic level is passed on to the next because organisms use much of the energy they con

  31. ENERGY PYRAMID • All energy originates from the sun (or inorganic chemicals). • Sunlight (radiant energy) is converted to digestible energy by plants during photosynthesis.

  32. ENERGY PYRAMID • When the plants are eaten, the energy is transferred to animals to sustain life. • Energy is transferred up the food chain.

  33. THE RULE OF TENS • Only 10% of the energy in a trophic level is passed on to the next level…90% of the energy is lost—where does it go? • Given off as HEAT!!

  34. BIOMASS PYRAMID • Biomass is the total amount of living tissue within a trophic level. • Represents the amount of potential food available at each trophic level.

  35. PYRAMID OF NUMBERS • Shows relative number of individual organisms at each trophic level.

  36. LIMITATIONS OF TROPHIC LEVELS Why can there not be too many links to one food chain?

  37. Each trophic level can support about one-tenth the amount of living tissue as the level below it, because only 10% of the energy is passed up!!!

  38. A few more things…

  39. HABITAT • The area where an organism lives • Includes both biotic and abiotic factors

  40. Biotic Bio- means: life Tic- means: pertaining to Biotic factors are the living organisms in a habitat! Abiotic Bio- means: life Tic- means: pertaining to A- means: no, not Abiotic factors are all the physical aspect of a habitat! Examples: soil, water, weather Biotic vs. Abiotic

  41. Water Air Soil Heat Light Abiotic Factors