Populations in ecosystems

• Population


  Groups of individuals of the same species that occupy the same habitat at the same time.
• Community

  All living things present in an ecosystem at a given time.
• Ecosystem

  All the abiotic and biotic factors of an area
• Habitat


  The place where an organism lives
• Ecological niche

  The role a species plays in its habitat
• Interspecific competition

  Competition between organisms of different species
• Intraspecific competition


  Competition between organisms of the same species.
• Predation

  One organism is consumed by another.
• Primary succession stages

  1. Seeds and spores carried by wind land on exposed rock and begin to grow

  2. Pioneer species (often moss and lichens) colonise new land

  3. Pioneer species die and decompose, forming basic soil

  4. Small plants and grasses grow in basic soil

  5. Small plants and shrubs die and decompose, forming deeper and more nutrient-rich soil

  6. Roots of small plants and shrubs form network to hold soil in place

  7. Larger plants, shrubs, and small trees grow in deeper, more nutrient-rich soil

  8. Large trees grow in sufficiently deep, nutrient-rich soil that can hold enough water
• Pioneer species

  First species to colonise new land (often moss and lichens)
• Climax community

  Final community formed, containing all the different plant and animal species that have now colonised the new land