Ecosystems

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Ecosystems
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Georgia Performance Standards

• S4L1 Students will describe the roles of
  organisms and the flow of energy within an
  ecosystem.
• Identify roles of producers, consumers, and
  decomposers in a community.
• Demonstrate the flow of energy through a food
  web/food chain beginning with sunlight and
  including producers, consumers, and decomposers.
• Predict how changes in the environment would
  affect a community (ecosystem) of organisms.
• Predict effects on a population if some of the
  plants or animals in the community are scarce or
  of there are too many.

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Essential Questions

• What is necessary for life?
• Are all organisms important?
• Why is a food web called a food web?
• Why do organisms become extinct?
• What are the roles of producers, consumers, and
  decomposers in the community?
• How does the flow of energy go through the food
  chain? Where does the energy come from?
• How will changes in the environment affect a
  community of organisms?
• How does population affect the number of plants
  and animals in the community?

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ECOSYSTEM

• An ECOSYSTEM is made up of all the living and
  nonliving things that interact in an area.
• Nonliving things in a ecosystem can include
  water, air, soil, and light. Nonliving things
  help the living things meet their needs.

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Using nonliving things to survive.

• Soil is the loose material that covers much of
  the Earths surface. It is made up of tiny pieces
  of rock, minerals, and organic matter.
• Organic matter is the remains of decaying plants
  and animals.
• Most plants grow best in this type of soil.

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Using nonliving things to survive

• Sunlight is needed by both plants and animals.
• Plants need sunlight to make food. Some plants
  and animals can only survive in warm
  temperatures.
• Some plants grow better in the shade. Shade
  protects living things from direct sunlight and
  high temperatures.

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Using nonliving things to survive

• Water is a nonliving thing that all plants and
  animals need in order to survive.
• A stream provides needed water for some of the
  animals and plants in the forest.
• Other plants and animals get their water from the
  rain.

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Using nonliving things to survive

• Air is a nonliving thing that all plants and
  animals must have in order to survive in an
  ecosystem.

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Different Ecosystems

• Each ecosystem has its own amounts of light and
  water, range of temperatures, and soil types.
• These conditions helps determine the kinds of
  living things that are able to survive there.
• A living thing can only survive in an ecosystem
  where its needs are met.

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Relationships in an ECOSYSTEM

• Every living thing has a role to play within its
  ecosystem. Every organism, plant, and animal has
  a particular job in its environment.
• Plants play the role of a PRODUCER. A producer is
  an organism that makes its own food.

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• The food that plants make is used for energy by
  the organisms that eat the plants.
• All organisms need energy.

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• Remember that plants use energy from the sunlight
  to make food.
• The plants use this food to grow and produce
  offspring (other plants).
• Some of the food is stored in the leaves, stems,
  and roots of the plant.

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• When an animal eats the plant, the energy from
  the plant is transferred to the animal.
• All animals are CONSUMERS. A consumer gets energy
  by eating plants, or by eating other animals that
  eat plants.
• Consumers use this energy to live.

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• ALL consumers in an ecosystem depend on producers
  for food.
• Without producers, the other organisms in an
  ecosystem could not survive.

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PHOTOSYNTHESIS

• Remember that plants make their own food by using
  energy from sunlight.
• The process by which plants make their own food
  is called PHOTOSYNTHESIS.
• This takes place in the plants leaves.

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• An animal that hunts other animals for food is
  called a PREDATOR.
• A PREY is an animal that is hunted for food by
  another animal.
• For example an owl is one kind of predator that
  and snake is one kind of prey that they owl hunts
  for food.

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• When a frog eats a plant, the frog gets energy
  from the plant.
• When the snake eats the frog, the snake gets
  energy from the frog and a smaller amount of
  energy from the plant.
• When the owl eats the snake, it also receives a
  small amount of energy from the plant and it also
  receives energy from the snake

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FOOD CHAIN

• A food chain shows the path of food energy in an
  ecosystem from plants to animals.
• Food chains are different in different
  ecosystems.

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FOREST FOOD CHAIN

• The FIRST link in any food chain is always the
  PRODUCER.

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FOREST FOOD CHAIN

• The SECOND link in a food chain is the VOLE. A
  vole is an herbivore or animal that eats only
  plants.
• The vole get energy from the plant.

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FOREST FOOD CHAIN

• The THIRD AND FOURTH links in a food chain are
  either carnivores or omnivores.
• A carnivore eats only other animals and an
  omnivore eats both plants and animals.

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FOOD WEB

• When TWO OR MORE food chains overlap, they form a
  FOOD WEB.
• In a food web, at least one plant or animal from
  each food chain is part of another food chain.

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FOOD WEB
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Helpful Organisms in an ecosystem.

• A helpful organism in an ecosystem is called a
  DECOMPOSER.
• A decomposer is a living thing that breaks down
  the remains of dead organisms.
• All food chains end with DECOMPOSERS

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• Decomposers help the environment. They keep it
  from becoming crowded with the remains of dead
  plants and animals.

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MICROORGANISM

• A microorganism is a tiny living thing that can
  only be seen with the aid of a microscope.
• Bacteria are one type of microorganism.
• Fungi is another type
• of microorganism.

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Why are decomposers important to an ecosystem?

• They release nutrients that plants and animals
  need to survive.
• The nutrients are released into the soil and
  water. This helps the plants and animals stay
  healthy.
• Decomposers also keep the environment clean and
  remove dead and decaying plants and animals so
  other living things can use the space.

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COMPOST

• People can create an ideal environment for
  decomposers by making a COMPOST.
• A compost pile or compost bin is a place that is
  set aside for the decay of materials that were
  part of once-living things.

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What type of things can go in a compost?

• You can put grass clippings, leaves, kitchen
  scraps, and many kinds of paper.
• These materials will be recycled by the fungi and
  bacteria in the compost.
• The decayed material can then be mixed with soil
  that can be used to grow plants for food.

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How do organisms change the environment?

• Whether it is an ant, a plant, an animal, or a
  human, every living thing causes changes to its
  environment.
• Sometimes the change to the environment is
  harmful to one organism but is helpful to
  another.

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• Think about a maple tree growing near a garden.
  As it grows, the tree provides a home to animals
  such as squirrels, birds, and other animals. Yet,
  the tree blocks sunlight and over time, only
  plants that require little light will be able to
  survive beneath the tree.

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How do humans change the environment?

• Humans change the environment in many ways.
• People have changed forests into cities, rivers
  into lakes, and hillsides into rubble.
• Some of these changes are good and some are bad.

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• For example, a DAM is used to hold back flood
  waters. It helps control the flow of the water
  which can improve river travel and it can provide
  electricity.
• The DAM can also cause harm because the flood
  waters used to deposit SILT along the rivers
  bank. The silt helped enrich the soil. Now
  farmers must use chemical fertilizers to help
  their plants grow.

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• Humans can be the biggest threats to the survival
  of a species.
• A SPECIES is a group of living things that
  produces living things of the same kind.

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• At one time, passenger pigeons numbered in the
  millions. Since humans killed so many of this
  species, it became EXTINCT.
• EXTINCT means that the species is no longer
  around.

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POPULATION

• What would happen to an ecosystem if there were
  not enough plants or animals?
• We have learned about the food chain. If there
  were not enough plants and animals in an
  ecosystem, the animals could not survive and
  would have to move or MIGRATE to another area in
  order to meet their needs and be able to survive.

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POPULATION

• What would happen if there were TOO many plants
  and animals in an ecosystem?
• All plants need sunlight. The more plants and
  trees, the less sunlight plants on the forest
  floor can get. Without this sunlight, the plants
  will die.
• If an ecosystem has too many animals and not
  enough food sources, the animals will have to
  migrate in order to meet their needs and be able
  to survive.

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Essential Questions

• What is necessary for life?
• Are all organisms important?
• Why is a food web called a food web?
• Why do organisms become extinct?
• What are the roles of producers, consumers, and
  decomposers in the community?
• How does the flow of energy go through the food
  chain? Where does the energy come from?
• How will changes in the environment affect a
  community of organisms?
• How does population affect the number of plants
  and animals in the community?