1. Abiotic and Biotic Factors
Presented by Kesler Science

2. Essential Questions:
What are the biotic and abiotic parts of an ecosystem?
How do organisms and populations in an ecosystem depend on and compete for biotic and abiotic factors?

3. Levels of organization in an ecosystem
Abiotic and Biotic Factors
Levels of organization in an ecosystem
Organism
An individual form of life, such as a plant, an animal, a bacterium, a protist, or a fungus.
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4. Levels of organization in an ecosystem
Abiotic and Biotic Factors
Levels of organization in an ecosystem
Populations
Comprised of all the individuals of a given species in an area at a certain time.
Not all individuals are identical.
Most importantly, not all members of the population are equal in their ability to survive and reproduce.
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5. Levels of organization in an ecosystem
Abiotic and Biotic Factors
Levels of organization in an ecosystem
Community
The populations of organisms of different species in a specific area at a given time.
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6. Ecosystem Abiotic and Biotic Factors
All of the living (biotic) and all of the physical nonliving factors (abiotic) in an area.
Ecosystems can only support a certain number of individuals based on the amount of food, water, living space, mates and other resources.
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7. Biotic Factors Abiotic and Biotic Factors Bio = prefix for life
Living or once-living organisms in an ecosystem.
Animals
Plants
Fungi
Bacteria
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8. Abiotic Factors Abiotic and Biotic Factors
A = prefix for not or without
Non-living elements in an ecosystem.
Water
Air
Soil – rocks and minerals
Sunlight
Temperature
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9. Quick Action – Abiotic and Biotic Factors
Stand up and find a partner to work with.
Make a T chart on a piece of paper.
List all the abiotic and biotic factors you see in this ecosystem.
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10. Quick Action – INB Template
Biotic
Factors
Glue this side to journal
Title INB Template
Cut out the Template
Glue into INB.
Define and make a list of biotic factors.
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11. Quick Action – INB Template
Abiotic Factors
Temperature
Air
Water
Soil, Rocks & Minerals
Light
Title INB Template
Cut out the Template
Glue along the narrow flap into our INB.
Draw and color pictures to represent each abiotic factor.
Fold along dotted lines.
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12. Quick Action – INB Template
Biotic
Factors
Abiotic
Draw a picture of a neighborhood park. List the biotic & abiotic factors under the flaps.
Title INB Template
Cut out the Template along dark lines.
Draw a picture of a neighborhood park on the top portion.
Glue top portion into INB.
Fold along dotted line.
List biotic and abiotic factors found in your picture under the appropriate flap.
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13. Quick Action – Abiotic and Biotic Factors
We’d be run over with mice on the planet!!!
What would happen if…?
Two mice produced 56 baby mice each year.
Each of these mice has 56 babies each year…
Calculate the total mice born in one year started by the original pair.
Have students assume that half of the babies born are female and half male.
Why doesn’t this really happen
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14. Carrying Capacity Abiotic and Biotic Factors
The largest number of individuals of the same species that an area can support.
If the population exceeds the carrying capacity, some individuals will die or move to another location.
Determined by elements called limiting factors.
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15. Quick Action - Abiotic and Biotic Factors
Stand up and find a partner
to work with.
What is the carrying capacity
of this fish tank?
What would happen if a small
bass was added to the tank?
How would the bass affect the carrying capacity of the tank?
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16. Limiting Factor Abiotic and Biotic Factors
An abiotic or biotic factor that limits the number of individuals that can live in an ecosystem.
Keeps the population from growing too large.
Two types of limiting factors you might want to talk about.
Density dependent limiting factors include disease, competition, and predation. Some density dependent limiting factors lower reproductive growth rate at lower population sizes and other factors lower reproductive growth rate at higher population sizes. Density dependent limiting factors are a form of biotic factor. Density independent limiting factors usually involve environmental stress. Density independent factors are not influenced by population change and and are usually abiotic. Some examples of density independent factors are nutrient limitation, climate extremes, and pollutants in the environment. 
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17. How do biotic factors limit other organisms in its environment?
Abiotic and Biotic Factors
How do biotic factors limit other organisms in its environment?
Competition for food
When resources are scarce
fewer organisms can survive.
When resources are plentiful
greater numbers of organisms
can survive.
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18. How do biotic factors limit other organisms in their environment?
Abiotic and Biotic Factors
How do biotic factors limit other organisms in their environment?
Predator-prey relationships
Greater the number of prey
the greater the number of
predators
Fewer the number of prey
the fewer the number of
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19. How do biotic factors limit other organisms in their environment?
Abiotic and Biotic Factors
How do biotic factors limit other organisms in their environment?
Parasitism – when an organism
lives off of a host organism
sometimes killing the host.
Worms in animal digestive tracts
Mistletoe in trees
Pine bark beetle invade and kill
pine trees.
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20. How do biotic factors limit other organisms in their environment?
Abiotic and Biotic Factors
How do biotic factors limit other organisms in their environment?
Disease – when outbreaks kill
off most or all of a population.
Influenza outbreak causes
millions of human deaths
in 1918.
Lyme Disease carried by ticks.
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21. How do biotic factors limit other organisms in their environment?
Abiotic and Biotic Factors
How do biotic factors limit other organisms in their environment?
Human activities destroy
animal habitats
development
damming rivers
clear cutting forest
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22. Quick Action – Abiotic and Biotic Factors
Get with a partner and discuss what competition is.
Look at the picture and describe what competition is taking place between the tree and the giraffe.
Explain how both have adapted to this competition.
Are these abiotic or biotic factors competing?
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23. How do abiotic factors limit organisms in an ecosystem?
Abiotic and Biotic Factors
How do abiotic factors limit organisms in an ecosystem?
Sun - availability increases photosynthesis
Plants compete for sunlight by growing taller than those around them.
Temperature
Warm lush areas support greater numbers of populations with less competition occurring.
Cold harsh areas support limited numbers of populations with greater competition occurring.
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24. How do abiotic factors limit organisms in an ecosystem?
Abiotic and Biotic Factors
How do abiotic factors limit organisms in an ecosystem?
Soil
Nutrient rich soils produces
more carbon, nitrogen, phosphorus
and support larger populations.
(Less competition)
Nutrient poor soils support smaller
populations. (more competition)
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25. How do abiotic factors limit organisms in an ecosystem?
Abiotic and Biotic Factors
How do abiotic factors limit organisms in an ecosystem?
Water
Availability, movement, temperature,
saltiness, chemical components
(quality) all affect competition and
ability to survive in populations.
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26. How do abiotic factors limit organisms in an ecosystem?
Abiotic and Biotic Factors
How do abiotic factors limit organisms in an ecosystem?
Changing Conditions
drought, flood, volcanic eruption, earthquake bring about changes that reduce populations.
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27. Quick Action – Abiotic and Biotic Factors
Get with a partner to discuss what might happen in the following situations.
A drought occurs and all the water in the pond dries up.
How many of the biotic organisms would survive?
How would they be able to survive?
Share your findings with the class.
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28. Abiotic and Biotic Factors
All biotic and abiotic factors are interrelated. In nature you will find that if one factor is changed or removed, it impacts the availability of other resources within the system.
What factor was removed from this ecosystem?
How did it affect the population in the ecosystem?
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29. Check for Understanding
Can you…
List the abiotic and biotic factors in an ecosystem?
Investigate how organisms and populations in an ecosystem compete for biotic and abiotic factors?
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