Which of the following terrestrial biomes has the highest primary productivity per unit area?

• A. Desert
• B. Temperate grassland
• C. Tundra
• D. Tropical rainforest

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the concept of primary productivity. Primary productivity refers to the rate at which plants and other photosynthetic organisms produce organic compounds (like glucose) from carbon dioxide and water using sunlight. It is measured per unit area and is influenced by factors such as sunlight, temperature, and nutrient availability.
2. Step 2: Analyze the characteristics of each biome listed. For example, deserts have low water availability and extreme temperatures, which limit plant growth. Temperate grasslands have moderate productivity due to seasonal variations in temperature and rainfall. Tundras are cold and have short growing seasons, limiting productivity. Tropical rainforests, on the other hand, have abundant sunlight, consistent warm temperatures, and high rainfall, which support dense vegetation and high productivity.
3. Step 3: Recognize that tropical rainforests have the highest biodiversity and dense vegetation, which contribute to their high primary productivity. The constant availability of resources allows plants to photosynthesize year-round.
4. Step 4: Compare the biomes based on their environmental conditions. Tropical rainforests have optimal conditions for photosynthesis, while deserts, temperate grasslands, and tundras face limitations such as water scarcity, temperature extremes, or short growing seasons.
5. Step 5: Conclude that tropical rainforests have the highest primary productivity per unit area due to their favorable environmental conditions, including high rainfall, warm temperatures, and abundant sunlight.