Energy & ecosystems

• How is energy transferred in an ecosystem?

  Through a food web
• What are plants referred to in a food chain?

  Producers
• Why are plants called producers?

  They produce their own carbohydrates
• What do plants use to produce carbohydrates?

  Carbon dioxide and water
• What is a trophic level?

  A stage in a food chain
• What happens to energy between trophic levels?

  A lot of energy is lost
• What is one way energy is lost in an ecosystem?

  Through respiration
• What is biomass in an ecosystem?

  The remaining energy available for the next level
• How can biomass be measured?

  Mass of carbon or dry mass of tissue
• How would you determine the biomass of a plant?

  Remove all water to get dry mass
• What do NPP and GPP stand for?

  Net Primary Productivity and Gross Primary Productivity
• What does GPP measure?

  Total energy from photosynthesis
• How is NPP calculated?

  GPP minus energy lost in respiration
• Why is NPP important?

  It indicates energy available for new biomass
• How do rainforest and desert ecosystems compare in productivity?

  Rainforests have higher GPP and NPP
• What is the formula for net production of consumers?

  N = I - F - R
• What does each letter in the formula N = I - F - R represent?

  N is net production, I is chemical energy store in ingested food, F is chemical energy lost to the environment in faeces and urine, R is respiratory losses
• Why is it important to standardize productivity measurements?

  To ensure fair comparisons between ecosystems
• What unit is used for energy in productivity calculations?

  Kilojoules (kJ)
• Why is productivity measured per year?

  To account for seasonal variations
• What are the components of productivity units?

  • Kilojoules (kJ) for energy
  • Per unit area (e.g., per hectare)
  • Per year for time
• What factors influence ecosystem productivity?

  • Abiotic factors: water, light intensity, temperature
  • Biotic factors: presence of green plants
• What is the relationship between photosynthesis and biomass?

  • More photosynthesis leads to more biomass
  • Biomass is the energy available for the food chain
• What is the significance of measuring NPP?

  • Indicates energy available for new biomass
  • Essential for understanding ecosystem productivity
• What is the main topic of the video?

  Energy transfer and productivity
• Who are the producers in an ecosystem?

  Plants
• What do producers create using carbon dioxide and water?

  Carbohydrates or organic matter
• What is lost between each trophic level?

  A lot of energy
• What are two ways energy is lost in an ecosystem?

  Respiration and excretion
• What is biomass in an ecosystem?

  Energy available to the next trophic level
• How can biomass be measured?

  Mass of carbon or dry mass of tissue
• How do you calculate biomass of a plant?

  Remove all water for dry mass
• What do GPP and NPP stand for?

  Gross primary productivity and net primary productivity
• What does GPP measure?

  Total energy from photosynthesis
• How is NPP calculated?

  GPP minus energy lost in respiration
• Why is NPP important?

  It indicates energy available for new biomass
• How does a rainforest compare to a desert in terms of productivity?

  Rainforest has higher GPP and NPP
• What is the formula for net production of consumers?

  Energy ingested minus energy lost
• What additional components are considered for consumers compared to plants?

  Energy lost in feces and urine
• What units are used to measure productivity?

  Kilojoules per hectare per year