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Your study guide information will be presented throughout this power point. Take notes. Ecological Pyramids:. graphs which illustrate the trophic levels in a community. AKS covered. 10 – compare and contrast food/energy requirements of different organisms.
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Your study guide information will be presented throughout this power point. Take notes.
Ecological Pyramids: graphs which illustrate the trophic levels in a community.
AKS covered. • 10 – compare and contrast food/energy requirements of different organisms. • 10a- compare food requirements in Autotrophs and Heterotrophs. • 10b- Illustrate food and energy requirements in Autotrophs and Heterotrophs. • Bio11b1 – explain the flow of energy through an ecosystem by arranging the components of a food chain energy pyramid and biomass pyramid.
Less Energy More Energy Most ecological pyramids are large at the base and narrow at the top. This is because every time that an organism is eaten by the next trophic level, some of the energy is lost as heat.
What is the AVERAGE energy loss from trophic level to trophic level?
The 10% Rule – Energy losses. • Energy transfers are never 100 percent efficient. • 10% of all energy once available at a trophic level may transfer to the next trophic level. • Some energy is lost at each step. • Limits the number of trophic levels in an ecosystem.
All Heat in the End. • At each trophic level, the bulk of the energy received from the previous level is used in metabolism. • This energy is released as heat energy and lost to the ecosystem. • Eventually all energy is released as heat.
Add this information to your study guide: Compare food and energy requirements in Autotrophs and Heterotrophs.
3 TYPES OF PYRAMIDS: • Pyramid of Biomass • Pyramid of Energy • Pyramid of Numbers
Pyramid of Biomass: • Illustrates the amount of biomass in each trophic level • Biomass weight is determined after dehydration. • Shows the amount of matter lost between trophic levels. • Measured in Kg, grams or pounds
Pyramid of Biomass Pyramid of Biomass
Pyramid of Biomass One problem: They can make a trophic level look like it has more energy than it really does. For example: A bird has a beak, feathers and a skeleton that would count as biomass even though it does not contribute to the overall flow of energy into the next trophic level.
Pyramid of Energy: • Shows the energy available at each trophic level. • The size of the blocks represents the proportion of productivity • Measured in Joules or Calories
Pyramid of Energy: • Most of the energy available to the community is in the 1st trophic level. • Only 10-20% of the energy is available to the next trophic level (≈ 90% lost)
Take out the Food chain you drew in the computer lab. Explain the flow of energy through an ecosystem using the food chain you created. You may use page 720 in textbook if you need more information.
Pyramid of Numbers: • Illustration of the number of organisms at each level
What kind of Pyramid is this? Energy, the trophic levels are measured in Kilocalories
Human Population Growth How can more people be supported on Earth when there is a limited supply of resources? It depends on what they are eating…
Human Population Growth • It requires 10 times as many crops to feed animals being bred for meat consumption as it would to feed the same amount of people on a vegetarian diet!! • The US could feed 800 million people with the grain that livestock eat. US population: 303 million
So Remember! Ecological (Trophic) Pyramids show: • Energy transfer and more importantly energy loss in an ecosystem. • Why there are more herbivores than carnivores in an ecosystem. • Why there are more plants than everything else combined (they support all other populations).
Add the answers to these questions to your study guide!! • Compare and contrast food/energy requirements of different organisms. • Compare food requirements in autotrophs and heterotrophs. • Draw and illustrate food and energy requirements in autotrophs and heterotrophs. • Explain why sunlight is the source of energy for most food webs. • Describe in a food web how matter is transferred from one organism to another and how it can be recycled between organism and their environments.
And these too. • What are the roles of a producer, consumer, and decomposer? • What is an energy role in an ecosystem? Give an example of each. • How is a decomposer different than a scavenger? • What is the difference between food chains and food webs? How are they similar? • Look at the Energy Pyramid on page 722 and be able to explain how it works.
The End or is it just the beginning?