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Ecological Pyramids

  • An ecological pyramid is a diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web.
    • Energy Pyramid
    • Biomass Pyramid
    • Pyramid of Numbers

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Source of ALL ENERGY is the SUN!!!

  • Theoretically
    • No limit to the number of trophic levels.
  • Realistically…
    • Only 10% of the energy is passed from one organism to the next.
  • Energy is used for:
    • Respiration
    • Movement
    • Reproduction
  • Most energy is LOST as heat to the surrounding environment.

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Energy Flow in Ecosystems

100,000

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  • Biomass
    • total amount of living tissue.
  • It is usually expressed in terms of grams.
  • It is the potential food available for each trophic level.

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Biomass Pyramid

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  • Based on the number of individual organisms at each trophic level.
  • NOT always in the shape of a pyramid.
    • A single tree with a lot of biomass and a lot of energy is still only 1 tree.
    • Many insects can live in the tree but have much less energy and biomass.
    • Ecological Pyramids Video

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Pyramid of Numbers

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Think about it…

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  • Why does energy decrease as you move up the pyramid?

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  • What happens to the population sizes as you move up the pyramid?

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Symbiosis = any relationship where two species live closely together.�

  • Mutualism
    • Both species benefit from the relationship.�
    • Example: flowers and insects
      • Flowers rely on insects to pollinate them to reproduce.
      • Insects rely on flowers for food such as nectar or pollen.
    • Example: Crocodiles and plovers
      • Plovers get a meal by eating meat stuck in the croc’s teeth.
      • Crocodile is saved from a disease by getting his teeth cleaned.

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Symbiosis = any relationship where two species live closely together.�

  • Commensalism
    • One benefits and the other is not helped or harmed.�
    • Example: barnacles and whales
      • Barnacles benefit by have whale carry them through water to food.
      • Whale is not helped or harmed.

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Symbiosis = any relationship where two species live closely together.�

  • Parasitism
    • One lives on or inside another and harms it.�
    • Examples:
      • tapeworms in intestines of mammals.
      • Fleas, ticks, and lice feed on blood of the host.

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Cycling maintains homeostasis= homeostasis is the organism’s regulation of its internal environment to maintain conditions suitable for survival.�

  • Matter in the form of nutrients, moves through the organisms at each trophic level.
  • Matter CANNOT be replenished like energy from sunlight.
  • Matter is constantly recycled.

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