Energy transfer

• How is energy transferred in an ecosystem?

  Through a food web
• Who are the producers in an ecosystem?

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

  Carbohydrates or organic matter
• What is the term for each stage in a food chain?

  Trophic level
• What is a significant way energy is lost between trophic levels?

  Through respiration
• What forms of energy loss occur besides respiration?

  Excretion and heat loss
• 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 the biomass of a plant?

  Remove all water to get 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
• Which ecosystem is more productive, rainforest or desert?

  Rainforest
• What is the formula for net production of consumers?

  Energy ingested minus energy lost
• What additional components are considered in the consumer formula?

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

  Kilojoules per hectare per year
• Why do we use per hectare in productivity calculations?

  To standardize results across areas
• Why is productivity measured per year?

  To account for seasonal variations
• What are the key concepts of energy transfer and productivity in ecosystems?

  • Energy transfer occurs through food webs.
  • Producers (plants) create carbohydrates.
  • Energy is lost at each trophic level.
  • Biomass is the energy available for the next level.
  • GPP measures total energy from photosynthesis.
  • NPP measures energy available for new biomass.
• What factors influence the productivity of an ecosystem?

  • Abiotic factors: water, light intensity, temperature
  • Biotic factors: presence of green plants
  • Higher productivity with favorable conditions
• What is the significance of measuring NPP in ecosystems?

  • Indicates energy available for growth
  • Essential for understanding ecosystem productivity
  • Helps compare different ecosystems