5.2.3 Productivity

• Consumers play a key role in secondary productivity by converting ingested organic matter into new biomass.
• Steps of secondary productivity in consumers

  1️⃣ Feeding

  2️⃣ Digestion

  3️⃣ Assimilation

  4️⃣ Excretion

  5️⃣ Respiration
• What does the formula $GPP =$$Total CO₂ Fixed by Photosynthesis$ represent?


  Gross Primary Productivity
• Productivity in ecology measures the rate at which energy is converted into organic matter.
• Match the productivity type with its description:

  GPP ↔️ Total energy captured by photosynthesis

  NPP ↔️ Energy stored after respiration
• Why does a rainforest have a high GPP but a lower NPP?

  Energy used for respiration
• Gross Primary Productivity (GPP) is the total amount of energy captured by plants
• Net Primary Productivity (NPP) is calculated by subtracting respiration losses from GPP.
• What are the key processes involved in secondary productivity?

  Feeding, digestion, assimilation
• In the primary productivity process, plants convert sunlight into organic matter and oxygen
• Secondary productivity results in biomass gain by consumers.
• What are the two main types of productivity in ecosystems?

  Primary and secondary
• Primary productivity uses sunlight as its main energy source
• Photosynthesis is the key process in primary productivity.
• What are the outputs of primary productivity?

  Organic matter, oxygen
• Gross primary productivity (GPP) is the total amount of energy captured by plants
• Productivity in ecology refers to the rate at which energy is converted into organic matter
• What does Gross Primary Productivity (GPP) measure?

  Energy captured by photosynthesis
• Net Primary Productivity (NPP) accounts for respiration losses.
• NPP is calculated by subtracting plant respiration from GPP.
• Why might a rainforest have a high GPP but a lower NPP?

  Plants use energy for respiration
• Understanding productivity helps in assessing ecosystem health.
• Secondary productivity measures the rate at which consumers convert organic matter into their own biomass
• Match the productivity type with its key process:

  Primary ↔️ Photosynthesis

  Secondary ↔️ Digestion
• How does light intensity affect primary productivity?

  Increases GPP until saturation
• Optimal temperature for photosynthesis is the same for all plant species.

  False
• Nitrogen and phosphorus are examples of nutrients crucial for primary productivity
• Arrange the factors affecting primary productivity based on their importance for photosynthesis.

  1️⃣ Light intensity

  2️⃣ Water availability

  3️⃣ Nutrient availability

  4️⃣ Temperature
• Drought conditions reduce primary productivity.
• Increased light intensity enhances primary productivity until it reaches saturation
• Drought conditions can significantly reduce primary productivity.
• Nitrogen and phosphorus are examples of nutrients vital for plant growth
• Arrange the factors affecting primary productivity from most positive to most negative impact.

  1️⃣ Optimal temperature

  2️⃣ Sufficient water availability

  3️⃣ Increased light intensity

  4️⃣ Drought conditions

  5️⃣ Nutrient deficiency
• Drought reduces Gross Primary Productivity (GPP).
• Nutrient deficiency limits Gross Primary Productivity (GPP) if deficient
• In a rainforest, nutrient availability can limit GPP due to rapid nutrient cycling.
• Gross Primary Productivity (GPP) measures the total amount of energy captured by plants through photosynthesis
• What is the formula for Net Primary Productivity (NPP)?

  $NPP =$$GPP - Respiration$
• A rainforest has a high GPP but a lower NPP due to energy loss from respiration.
• Secondary productivity measures the rate at which consumers convert organic matter into their own biomass