Lecture Notes: Biotic and Abiotic Factors

Introduction

• Topic: Understanding biotic and abiotic factors in ecosystems.
• Objective: Identify and explain the influence of biotic and abiotic factors on organisms and ecosystems.

Biotic Factors

• Definition: Living factors that affect other organisms or shape the ecosystem.
• Examples:
  • Predation: Affects population levels of prey species.
  • Competition: For resources such as habitat and food.
  • Disease: Impacts health and population levels.
  • Food Availability: Determines energy sources and feeding relationships.
• Key Point: Biotic factors involve interactions among living organisms like animals, plants, and microorganisms.

Abiotic Factors

• Definition: Non-living components of the environment affecting organisms.
• Examples:
  • Light Intensity: Affects photosynthesis rates.
  • Temperature: Influences enzyme activity and growth rates.
  • Carbon Dioxide Concentration: Impacts photosynthesis.
  • Moisture Levels: Essential for plant growth and survival.
  • Wind Intensity and Direction: Influences temperature and humidity.
  • Soil pH and Mineral Content: Affects plant health and growth.
• Impact: Changes in abiotic factors can affect climatic and soil conditions, influencing the ecosystem.

Case Study: Clownfish and Sea Anemone

• Biotic Factors:
  • Predation: By larger fish or eels.
  • Habitat Competition: With sea anemones.
  • Food Competition: For plankton and algae.
  • Disease Burden: Affects health and survival.
• Abiotic Factors:
  • Water Temperature: Varies with time and season.
  • Oxygen Concentration: Affects respiration.
  • Acidity and Salinity Levels: Essential for suitable living conditions.
  • Light Intensity and CO2 Levels: Indirectly influence the clownfish through effects on sea anemone.

Conclusion

• Focus on identifying biotic and abiotic factors and predicting outcomes of their changes.
• Application includes understanding interactions among these factors in relation to specific organisms like the clownfish.

• Summary: Recognize and explain how changes in biotic and abiotic factors can influence ecosystems and individual species.
• Next Steps: Look forward to exploring more complex interactions and impacts in future sessions.