Which of the following terrestrial biomes has the highest net primary productivity?

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

Answer: (D)

Verified step by step guidance

1. Understand the concept of net primary productivity (NPP): Net primary productivity is the rate at which plants in an ecosystem produce usable chemical energy (biomass) after accounting for the energy they use for respiration. It is a measure of how much energy is available to support the ecosystem's food web.
2. Review the characteristics of each biome: Tropical rainforests have warm temperatures, high levels of rainfall, and abundant sunlight, which support year-round plant growth. Temperate grasslands have moderate rainfall and seasonal temperature variations. Deserts are characterized by low rainfall and extreme temperatures, limiting plant growth. Tundras have cold temperatures, short growing seasons, and permafrost, which restrict plant productivity.
3. Compare the factors influencing NPP: Tropical rainforests have the most favorable conditions for photosynthesis, including consistent warmth, high moisture, and sunlight. These factors lead to the highest NPP among terrestrial biomes. In contrast, deserts, tundras, and temperate grasslands have limiting factors such as water scarcity, cold temperatures, or seasonal growth periods, resulting in lower NPP.
4. Recognize the ecological significance of tropical rainforests: Due to their high NPP, tropical rainforests support a vast diversity of plant and animal species. They play a critical role in global carbon cycling and oxygen production.
5. Conclude that tropical rainforests have the highest net primary productivity among the listed biomes, based on their optimal environmental conditions for plant growth and energy production.