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Understanding Ecology and Ecosystem Interactions

Apr 16, 2025

Ecology Lecture Notes

Key Concepts in Ecology

  • Organism Relationships

    • Example: Mice have relationships with other mice, plants they eat, predators, nearby animals, and the environment.
    • Example: Mice interact with the environment by breathing oxygen, exhaling carbon dioxide, and burrowing holes.
  • Impact of Ecosystem Changes

    • Changes in one part of the ecosystem (e.g., a decrease in mouse population) can affect other parts (e.g., less food for predators, soil quality decreases).

Important Terms in Ecology

  • Habitat

    • Definition: Place where an organism lives.
    • Examples: A field, forest, or a basement for mice.
  • Population

    • Definition: All organisms of a particular species living in a habitat.
    • Example: All mice living in a field.
  • Community

    • Definition: All populations of different species living together in a habitat.
    • Example: Includes mice, owls, plants in a field.
  • Biotic Factors

    • Definition: Living factors of the environment.
    • Examples: Availability of food, number of predators.
  • Abiotic Factors

    • Definition: Non-living factors of the environment.
    • Examples: Temperature, soil pH.
  • Ecosystem

    • Definition: Interaction of a community of living organisms with non-living parts of their environment.
  • Ecology

    • Focus: Understanding how ecosystems function and change over time.

Key Processes in Ecosystems

  • Competition

    • For animals: Involves space (territory), food, water, mates.
    • For plants: Involves light, space, water, mineral ions from the soil.
    • Result: Organisms compete due to limited resources.
    • Examples: Lions and hyenas competing for a wildebeest; male deer competing for females.
  • Interdependence

    • Definition: All species depend on other species in some way.
    • Example: Food webs show feeding relationships and dependency.
    • Impact: Changes in one species affect others.
    • Example: Increase in mouse population affects grass availability for rabbits and grasshoppers, impacting hawk population and other species.

Predicting Changes in Ecosystems

  • Understand relationships to predict knock-on effects of changes.
  • Example: Mouse population increases lead to less grass, affecting rabbits, grasshoppers, and indirectly hawks, shrews, and sparrows.

Conclusion

  • Understanding these concepts is key to predicting how ecosystems function and might change in the future.