1.4 Primary Productivity

• What is primary productivity measured as?

  Carbon fixed per unit area
• Gross Primary Productivity (GPP) is the total amount of carbon fixed by producers
• Net Primary Productivity (NPP) is the amount of carbon left after producers use some for respiration.
• What is the formula relating NPP, GPP, and respiration?

  $\text{NPP} =$$\text{GPP} - \text{Respiration}$
• Light is required for photosynthesis, which is essential for primary productivity
• Why is water necessary for primary productivity?

  Hydrates plant cells
• Nutrients are essential for growth and photosynthesis in producers.
• How does temperature affect primary productivity?

  Influences metabolic rates
• Match the type of primary productivity with its definition:

  Gross Primary Productivity (GPP) ↔️ Total amount of carbon fixed by producers

  Net Primary Productivity (NPP) ↔️ Carbon left after producer respiration
• Order the factors affecting primary productivity from most direct to least direct effect:

  1️⃣ Light

  2️⃣ Water

  3️⃣ Nutrients

  4️⃣ Temperature
• Photosynthesis increases with higher light intensity
• Water availability directly affects primary productivity.
• How do nutrients influence Net Primary Productivity (NPP)?

  Bolster biomass production
• Primary productivity increases with temperature until an optimum
• Match the type of primary productivity with its formula:

  Gross Primary Productivity (GPP) ↔️ $GPP$

  Net Primary Productivity (NPP) ↔️ $GPP - Respiration$
• What is the definition of Gross Primary Productivity (GPP)?

  Total carbon fixed by producers
• Net Primary Productivity (NPP) is the carbon remaining after producers use some for respiration
• The formula for NPP is \text{NPP} = \text{GPP} - \text{Respiration}</latex>.
• What does Gross Primary Productivity (GPP) measure?

  Total carbon fixed
• Net Primary Productivity (NPP) is the carbon remaining after producers use some of it for respiration
• The relationship between GPP and NPP is $\text{NPP} =$$\text{GPP} - \text{Respiration}$.
• Match the aspect with its corresponding term:

  Total carbon fixed ↔️ GPP

  Carbon remaining after respiration ↔️ NPP
• Only NPP is available to consumers
• NPP is calculated as GPP minus respiration.
• What is the primary role of light in primary productivity?

  Required for photosynthesis
• Water increases primary productivity by hydrating cells.
• NPP is directly proportional to nutrient availability.
• Which ecosystem is known for its high primary productivity?

  Tropical rainforest
• Deserts have low primary productivity due to limited water and nutrients.
• Order the key ecological benefits of primary productivity:

  1️⃣ Supporting food webs

  2️⃣ Carbon sequestration

  3️⃣ Nutrient cycling