Answer: nutrient cycling.
- A nutrient cycling
- B the energy flow
- C plant succession
- D simple predation
Correct answer: A. nutrient cycling
Explanation: Nutrient (biogeochemical) cycling recycles elements through the ecosystem.
Energy pyramid showing a simple food chain (producer to herbivore to carnivore) with energy decreasing roughly tenfold at each trophic level.
Concept context
Ecosystems, food chains, energy flow, nutrient cycles, biodiversity, and conservation.