Limiting Factors in an Ecosystem

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Limiting Factors in an Ecosystem
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Several Abiotic Factors Can Limit Population
Growth

• Limiting factor principle
• Too much or too little of any abiotic factor can
  limit or prevent growth of a population, even if
  all other factors are at or near the optimal
  range of tolerance
• Directly relates to
• Carrying Capacity (K)
• The maximum population of a given species that a
  particular habitat can sustain indefinitely
  without being degraded (we will return to this
  concept in Chapter 5)

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Examples of Limiting Factors

• Temperature
• Animals have a thermal range in which their
  bodies work
• Digestion Metabolism
• Reproduction
• Locomotion (escaping predators)
• Foraging (finding food)
• Space
• How many organisms can physically occupy an area?
• Food
• Is the environment able to support an infinite
  number of organisms?

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Range of Tolerance for a Population of Organisms

• INSERT FIGURE 3-10 HERE

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Temperature of a Scorpioneven invertebrates
have limiting factors
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Raccoon Activity

• Objectives
• Define a major component of habitat
• Identify a limiting factor
• Recognize the importance of a suitable habitat
  and limiting factors
• Methods
• Students will become raccoons to look for
  components of a habitat

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Raccoon Activity

• Background
• Since raccoons are omnivores and eat a variety of
  food, each color of paper represents a different
  food item
• Everyone will get a paper bag that represents the
  raccoons cache (stash of food hidden by an
  animal to be used at a later date, i.e. winter)
• Food (paper) will be scattered about in a
  forest (open area)

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Raccoon Activity

• Procedure
• Raccoons must walk through the forest
• (raccoons do not run with their food)
• Gather food
• Hide it in the cache ONE AT A TIME!!!!
• You cannot carry more than one food item at a
  time
• Other raccoons can steal from your cache
• Do not announce when you do this, raccoons do not
  make it known when they are stealing one
  anothers food!

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Raccoon Activity

• Heres the catch
• Not all raccoons are healthy
• You will be randomly assigned a raccoon history
  and must it out while gathering your food

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Raccoon Activity

• BROWN- nuts (acorns, walnuts, hickory nuts)
• 25 of diet
• PURPLE- berries fruits
• 25 of diet
• YELLOW- insects (grub, larvae, ants, termites)
• 15 of diet

• RED- meat (rodents, amphibians, reptiles, birds,
  eggs)
• 15 of diet
• GREEN- plants (leaves, grasses, herbs)
• 20 of diet
• BLUE- water

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Summary

• Did all raccoons get enough nutrients to
  survive?
• What are the limiting factors?
• How does this affect the survival of each
  animal?
• What does this tell you about carrying capacity?