4.2 - Decay

• What is decomposition often called?

  Rotting
• What is the process of decomposition?

  Breaking down dead organic matter into simpler substances
• What are some substances produced during decomposition?

  Carbon dioxide, water, simple sugars, minerals
• Why is decomposition essential in ecosystems?

  It recycles elements throughout the ecosystem
• How does leaf decomposition recycle nutrients?

  • Leaves fall and decompose in soil
  • Nutrients like carbon, nitrogen, magnesium are released
  • Plants absorb these nutrients for growth
• What are the two groups of organisms that carry out decomposition?

  Detritus feeders and decomposers
• What are detritus feeders?

  Small animals that feed on dead organic matter
• What environmental conditions affect the rate of decomposition?

  1. Oxygen availability
  2. Temperature
  3. Water content
• How does oxygen availability affect decomposition?

  Higher oxygen increases aerobic respiration and decomposition
• What happens to decomposition rates at higher temperatures?

  Increased kinetic energy raises reaction rates
• What can happen if the temperature rises too high during decomposition?

  Enzymes may denature, slowing decomposition
• Why do decomposers need water?

  Water is essential for their survival
• How does water content affect decomposition rates?

  Moist conditions increase decomposition rates
• What happens if soil becomes waterlogged?

  Oxygen levels fall, decreasing decomposition
• What is decay?


  The breakdown of organic matter by the action of decomposers
• Name two types of detritus feeders?

  • Woodlice
  • Worms
• What effect would lowering the temperature have on the rate of decay of an apple?


  Decrease the rate of decay
• Oxygen is important for decomposition. 

  What process do bacteria need oxygen for?

  aerobic respiration
• Why could the rate of decomposition fall if soil becomes waterlogged?

  • Water fills the air gaps within the soil, so there will be) less oxygen 
  • Less aerobic respiration
  • Fewer chemical reactions and thus slower decomposition
• What does anaerobic mean?


  Without oxygen