Populations and Ecosystems

• The environment includes both non-living (abiotic) factors, such as temperature, and living (biotic) factors, such as competition and predation.
• Ecosystems are dynamic systems made up of a community and all the non-living factors of its environment. Within an ecosystem there are two major processes to consider:

  • the flow of energy through the system.
  • the cycle of elements within the system.
• A population is a group of individuals of a species that occupy the same habitat at a given time.
• Populations of different species form a community.
• A habitat is the place where an organism normally lives and is characterised by physical conditions and other types of organisms present.
• Within each habitat there are smaller units, each with their own microclimate, called a microhabitat.
• A niche describes how an organism fits into the environment. A niche refers to where an organism lives and what it does there. No two species occupy the same niche. This is known as the competitive exclusion principle.
• Conservation is the management of the earth's natural resources by humans. It helps maintain biodiversity and ecosystems. Main reasons for conservation are:

  • Personal
  • Ethical
  • Economic
  • Cultural
  • Aesthetic