8.6 Biodiversity

• Ecosystem diversity

  Relates to the resilience of an ecosystem to changes in the environment
• Typically, the more diverse an ecosystem is, the more resilient it is to changes in the environment
• Ecosystems with less diversity

  • Are more fragile and minor changes can potentially cause a disruption in the entire structure
• Diversity of species within an ecosystem

  Influences the organization of the ecosystem (e.g. number of producers, consumers)
• Long term structure of an ecosystem can be stabilized with more diversity
• Changes in diversity


  Can cause short term and long term structural changes in an ecosystem
• Abiotic factors that contribute to maintaining ecosystem diversity


  • Climate
  • Water availability
  • Nutrient availability
  • Light availability
• Biotic factors that help maintain ecosystem diversity


  • Producers supporting other organisms
  • Dominant predators keeping prey populations under control
• Keystone species

  Species whose effect or impact on the overall health or structure of an environment is disproportionate relative to their abundance
• When keystone species are removed from an ecosystem, the ecosystem often collapses
• Overpopulation of prey species can result in depletion of resources, but keystone predators can control prey populations and make more resources available to other organisms
• Natural or artificial ecosystems with fewer component parts are less resilient to changes in the environment and more fragile