Stability

• How do stable ecosystems persist over time?

  They remain unchanged for long periods
• How long has the Borneo lowland rainforest existed?

  About 140 million years
• What can disrupt stabilizing ecosystems?

  Disruptions may alter ecosystem stability
• What is needed for an ecosystem to remain stable?

  A constant energy supply and nutrient cycling
• What are the cycles that contribute to nutrient cycling?

  Carbon, nitrogen, and phosphorus cycles
• Why is genetic variation important for species survival?

  It helps survive selective pressures
• What climate factors contribute to ecosystem stability?

  Temperature and precipitation
• How does poaching affect ecosystems?

  It alters species diversity
• What is eutrophication?

  Excess nutrients causing algae blooms
• How does climate change disrupt ecosystems?

  It affects sensitive ecosystems like coral reefs
• What is a tipping point in an ecosystem?

  A level of disturbance causing irreversible change
• What are positive feedback loops in ecosystems?

  Processes that amplify changes in ecosystems
• How does deforestation affect transpiration in the Amazon rainforest?

  It reduces the number of trees, decreasing transpiration
• What happens when drought occurs in an ecosystem?

  It can lead to increased fires
• What are mesocosms?

  Miniature ecosystems for controlled experiments
• Why are closed systems preferred in mesocosm experiments?

  They illustrate nutrient cycling effectively
• What is a disadvantage of mesocosms?

  They cannot replicate all natural factors
• What is a keystone species?

  An organism with a disproportionate effect on its community
• What happens when a keystone species is removed?

  The entire ecosystem may collapse
• What was the focus of Paine's sea star experiment?

  The effect of sea stars on ecosystem stability
• What happened to the ecosystem when sea stars were removed in Paine's experiment?

  Mollusks dominated, crowding out other organisms
• What term do biologists prefer over "starfish"?

  Echinoderms
• What are the key factors affecting ecosystem stability?

  • Constant energy supply (e.g., from the Sun)
  • Nutrient cycling (carbon, nitrogen, phosphorus)
  • Genetic variation within species
  • Relatively stable climate (temperature, precipitation)
• What are the advantages and disadvantages of using mesocosms in ecological studies?

  Advantages:

  • Controlled experiments
  • Easier to replicate
  • Isolate specific variables

  
  

  Disadvantages:

  • Cannot replicate all natural factors
  • Limited by artificial conditions
• What is the significance of keystone species in ecosystems?

  • Disproportionate impact on community structure
  • Removal can lead to ecosystem collapse
  • Essential for maintaining biodiversity