Name the dark coloured substance formed by the action of decomposers on dead plant leaves.

Answer

**Step-by-Step Solution:**

1. **Understand the Role of Decomposers**: Decomposers are organisms that break down dead organic matter, such as dead plant leaves, into simpler substances. This process is essential for nutrient cycling in ecosystems.

2. **Identify the Process**: When decomposers act on dead plant leaves, they break them down through decomposition. This process involves the breakdown of complex organic materials into simpler forms.

3. **Recognize the Product**: The action of decomposers on dead plant leaves leads to the formation of a dark-colored substance. This substance is rich in nutrients and beneficial for soil health.

4. **Name the Substance**: The dark-colored substance formed from the decomposition of dead plant leaves is called **humus**. Humus is a vital component of soil, contributing to its fertility and structure.

5. **Conclude**: Therefore, the answer to the question is **humus**.

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