1. Dependence and Competition

2. Biotic or Abiotic?
Identify each factor in the “Features” column as Abiotic or Biotic
Abiotic
Biotic
Abiotic
Biotic
Abiotic
Abiotic
Abiotic

3. What is the difference between biotic and abiotic factors?
Biotic refers to anything that is living
Abiotic refers to anything nonliving
Both refer to factors that are needed by organisms to survive

4. Examples of Biotic Factors?
Predators
Food
Disease
Parasites
Examples of Abiotic Factors?
Light
Shelter
Soil
Water
Space
Temperature

5. An invasive species is a plant or animal that is introduced into a different ecosystem and has a very high survival rate. The invasive species’ population is not limited by other organisms (biotic) or other abiotic factors. What are some examples of invasive species?
Feral Hogs from Europe
Hydrilla from Asia
Killer Bees from Africa
Fire Ants from South America

6. Is an invasive species an example of a biotic factor, abiotic factor or neither?
A biotic factor because it is a living part of the ecosystem
Zebra Mussels from Russia
Paperbark tree from Australia

7. Why are these factors important?
Which do you think is more important for an organism’s survival, biotic or abiotic factors?
Biotic and Abiotic Factors are equally important.
Why are these factors important?
Organisms need food, water, space and shelter to survive. Organisms must compete with other organisms for these factors.

8. What are limiting factors?
Limiting factors are biotic and abiotic factors in the environment that limit or support the survival of organisms.

9. Environmental Conditions Ideal for Organism 1
Read the factors required for Organism 1 to survive. Highlight the boxes on the table from Individual Ecosystem describing the factors required for Organism 1 to survive.
Environmental Conditions Ideal for Organism 1
Factor
Requirements for Survival
Food
Makes its own food (autotroph)
Water
Requires moderate amount of water for best growth
Light
Needs at least 6 hours of sunlight daily to thrive; some plants may barely survive with less light
Temperature
Cannot grow and survive when temperature is below 32oF
Habitat space requirements
Competes for space with other plants; requires some space to live
Soil composition
Thrives best in fertile soil but can live in less fertile soil; cannot survive in poor solid or rock areas
Predation
Some animals eat this plant

10. Factor
Requirements for Survival
Food
Makes its own food (autotroph)
Water
Requires moderate amount of water for best growth
Light
Needs at least 6 hours of sunlight daily to thrive; some plants may barely survive with less light
Temperature
Cannot grow and survive when temperature is below 32oF
Habitat space requirements
Competes for space with other plants; requires some space to live
Soil composition
Thrives best in fertile soil but can live in less fertile soil; cannot survive in poor solid or rock areas
Predation
Some animals eat this plant
Compare the characteristics of your ecosystem to the factors required for Organism 1 to survive.
How well would Organism 1 survive in the ecosystem you have?
Compare your ecosystem with the other ecosystems of your group. Discuss the following questions and be prepared to share your group answers with the class.

11. Which of the ecosystems in your group is best suited for Organism 1’s survival? Explain your thinking.
Is the selected ecosystem more likely to support a small or large population of the organisms? Explain your thinking.
Explain why Organism 1 would or would not be able to survive in your ecosystem. Explain how the biotic and abiotic conditions in the ecosystem meet the survival requirements of Organism 1.

12. Is the selected ecosystem more likely to support a small or large population of Organism 1? Explain
The more the ecosystem’s factors and the organism's needs match, the more likely a larger population will survive.
Which factors were the most limiting in the survival or your organism? Explain
If the ecosystem and organism’s needs are on opposite sides of the chart, then these would be the most limiting factors.

13. What would happen if another organism with survival requirements similar to Organism 1 was introduced in your group’s ecosystem?
The two organisms would be competing for the same abiotic and biotic factors in the ecosystem
What may happen as a result of this new organism being introduced into the ecosystem?
Since organisms will be competing for the same resources, the population of Organisms 1 may decline. The second organism may or may not be able to get a foothold into the ecosystem.