Nutrient Cycles

• What is the definition of a natural ecosystem?

  An ecosystem that is not farmed or managed in any way.
• What is the definition of detritus?

  Dead plants and animals, plus waste material such as urine and faeces. They all contain protein and carbs.
• What is the definition of a detritivore?

  An organism that feeds on detritus. These are larger organisms, such as earthworms and some species of beetles.
• What is the definition of a decomposer?

  Bacteria and fungi that digest detritus and then respire using the carbs they have gained.
• What is the definition of a microbial saprobiont/saprotroph?

  This term describes most decomposers. They carry out extracellular digestion by secreting enzymes into their surroundings.
• What is the definition of mycorrhizal fungi?

  Any fungal species that associates with plant roots, growing around them and increasing their surface area for uptake.
• What is the definition of a symbiotic relationship?

  A relationship between two organisms where at least one organism benefits. An example is parasitic relationships.
• What is the definition of a mutualistic relationship?

  A symbiotic relationship where both organisms benefit. Mycorrhizal fungi have a mutualistic relationship with plant roots.