Competition and Independence

Levels of Organization in an Ecosystem

1. Habitat – The environment where an organism lives.

   • Example: African grasslands for elephants.

2. Population – All the organisms of the same species in a geographical area.

   • Example: All elephants in the grasslands.

3. Community – All populations of different species living in the same habitat.

   • Includes all living organisms (biotic factors).

4. Abiotic factors – Non-living parts of an environment.

   • Examples: Water, minerals in soil, temperature, light intensity.

5. Ecosystem – The interactions between biotic and abiotic factors.

Competition

• Living organisms compete for limited resources:
  Plants: light, space, water, mineral ions.
  Animals: food, water, mates, territory.

Interdependence

• Species rely on each other for survival:

  • Food: Lions eat zebras; zebras eat grass.

  • Shelter: Trees provide shade and protection.

  • Pollination/Seed dispersal: Bees pollinate flowers; birds disperse seeds.

• Removing one species can affect the whole community.

Stable Communities

• Populations remain fairly constant over time.

• Balance exists between species populations and abiotic resources (e.g., water, nutrients).