If there were no decomposers in an ecosystem, which of the following would most likely happen?

• A. Dead organic matter would accumulate, and nutrients would not be recycled back into the ecosystem.
• B. Predator populations would rapidly increase.
• C. Primary producers would increase in number due to more available nutrients.
• D. Energy flow through the ecosystem would become more efficient.

Answer: (A)

Verified step by step guidance

1. Understand the role of decomposers in an ecosystem: Decomposers, such as fungi and bacteria, break down dead organic matter into simpler substances, releasing nutrients like nitrogen, phosphorus, and carbon back into the soil and atmosphere. These nutrients are essential for primary producers (plants, algae, etc.) to grow and sustain the ecosystem.
2. Analyze the scenario where decomposers are absent: Without decomposers, dead organic matter (e.g., plant and animal remains) would accumulate in the ecosystem. This would prevent the release of essential nutrients back into the soil, disrupting the nutrient cycle.
3. Evaluate the impact on primary producers: Since nutrients are not being recycled, primary producers would face a shortage of essential nutrients, leading to a decline in their growth and population, not an increase.
4. Consider the effect on energy flow: Energy flow in an ecosystem depends on the transfer of energy through trophic levels (producers, consumers, decomposers). Without decomposers, the energy stored in dead organic matter would not be released back into the ecosystem, making energy flow less efficient, not more efficient.
5. Conclude the most likely outcome: The absence of decomposers would result in the accumulation of dead organic matter and a disruption of nutrient recycling, which would negatively impact the entire ecosystem. This aligns with the first option provided in the question.