energy and ecosystems

• define biomass

  total mass of living material
• suggest why dry biomass is used instead of raw biomass to compare chemical energy store

  • there are different amounts of water in different tissues within an organism
  • calculating dry biomass allows more accurate comparisons to be made
• why can there not be more than 5 trophic levels ?

  energy is lost at each trophic level - total number of energy available decreases at each trophic level - too little energy available further up the chain to support higher trophic levels
• List three ways farmers can overcome the effects of limiting factors of photosynthesis

  1. Use artificial lighting to maintain a high light intensity. 
  2. Re-use carbon dioxide waste to maintain a high carbon dioxide concentration. 
  3. Use greenhouses kept at specific temperatures