1. Abiotic and Biotic Factors

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. 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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10. 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:
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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11. 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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12. 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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13. 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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14. 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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15. 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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16. 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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17. 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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18. 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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19. 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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20. 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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21. 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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