1. Abiotic and Biotic

2. Ecosystems
• Interacting populations of organisms with
biotic and abiotic factors

3. Abiotic Factors
• Non-living factors that affect the ecosystem:
light, space, temperature, shelter, water, soil
composition

4. Biotic Factor
• Living factors that affect the ecosystem: food
sources, other population members, other
species

5. Competition
• More than one individual, or population in an
ecosystem, relies upon the same limited
resources

6. Niche
• Role in an ecosystem

7. Limiting Factor
• A biotic or abiotic factor needed as a resource
for survival; depletion prevents growth or
expansion of the organism or population

8. Summary
• Resources for an organism’s habitat, including
space, food, shelter, and water, may be limited or
depleted by competition. Two species cannot
operate in the same niche in the same
environment.
• Organisms rely on natural resources in their
environment such as quantity of light, water
supply, and suitable temperature.
• Competition occurs when niches overlap and
organisms seek the same resources, especially
when the population density is high.