Competition (SQA National 5 Biology): Revision Note

Interspecific competition

• Competition is an interaction that occurs when:

organisms compete for the same resources, and the resources are in short supply

• Competition can be interspecific, meaning that it occurs amongst individuals of different species when they require one or several of the same resources

  • Interspecific competition occurs when the niches of two species overlap

• Different species might compete for, e.g.:

  • food

  • water

  • light

  • space

Intraspecific competition

• Intraspecific competition occurs amongst individuals of the same species

• Individuals of the same species have the same resource requirements, so individuals will compete for all of their resources

  • This differs from interspecific competition, which tends to be for just a few resources

  • Intraspecific competition is therefore more intense than interspecific competition

• Organisms may compete with members of the same species for, e.g.:

  • light

  • water

  • space

  • food

  • mates