How does nutrient cycling differ between tropical rainforests and temperate forests, and what are the implications for ecosystem services?

• A. In tropical forests, nutrients are stored mainly in biomass and cycle rapidly; soils are often nutrient-poor.
• B. In tropical forests, most nutrients are stored in soils.
• C. Temperate forests store most nutrients in leaf litter.
• D. Nutrient cycling is identical in tropical and temperate forests.

Answer: (A)

Where nutrients sit and how fast they move through the system shapes the way nutrient cycling works and the services ecosystems provide. In tropical rainforests, the warm, wet climate drives very fast decomposition and nutrient uptake, so most nutrients are stored in living biomass rather than in the soil. The soils themselves tend to be very weathered and leached, making them nutrient-poor despite the forest’s high productivity. This means the cycle is rapid and tightly linked to the living vegetation: nutrients quickly cycle through leaves, stems, and roots and are returned to the canopy rather than staying in the soil.

This pattern supports high primary productivity and rapid recovery after disturbance, and it helps sustain biodiversity and climate regulation through carbon stored mainly in biomass. However, because nutrients are largely tied up in living organisms and soils are poor, large-scale losses of biomass (through logging, fire, or erosion) can lead to sharp, long-lasting declines in nutrient availability and slower recovery.

Temperate forests, by contrast, experience cooler temperatures and often slower decomposition, so a larger share of nutrients is stored in soils and leaf litter. The nutrient cycle is slower, but soil reservoirs can provide more stable, longer-term fertility and carbon storage in the soil, buffering productivity against short-term fluctuations.

That combination aligns with the statement that tropical forests store most nutrients in biomass and cycle them rapidly, with soils that are often nutrient-poor. The other options don’t fit tropical–temperate contrasts: soils aren’t the dominant nutrient reservoir in the tropics, leaf litter isn’t the primary reservoir in temperate forests, and nutrient cycling is not identical across these biomes.