Choose odd one out w.r.t. functional aspects of ecosystem.

Options

A. Energy flow
B. Decomposition
C. Species composition
D. Nutrient cycling

Answer

### Step-by-Step Solution

1. **Understanding Functional Aspects of Ecosystem**:
- The functional aspects of an ecosystem include processes and interactions that sustain the ecosystem. These typically involve energy flow, nutrient cycling, and the roles of different organisms within the ecosystem.

2. **Identifying Components of Ecosystem**:
- An ecosystem consists of biotic components (like autotrophs, heterotrophs, and decomposers) and abiotic components (like sunlight, water, and minerals). Each of these components plays a role in the functioning of the ecosystem.

3. **Recognizing the Key Functional Aspects**:
- The key functional aspects include:
- **Energy Flow**: The transfer of energy through the food chain.
- **Decomposition**: The breakdown of dead organic matter by decomposers.
- **Nutrient Cycling**: The movement and exchange of organic and inorganic matter back into the production of living matter.

4. **Evaluating Species Composition**:
- Species composition refers to the variety and abundance of different species in a given area. While it is important for biodiversity, it does not directly influence the functional processes of energy flow, decomposition, or nutrient cycling.

5. **Conclusion**:
- Based on the above understanding, the odd one out with respect to the functional aspects of the ecosystem is **species composition**. It does not directly contribute to the functional processes like energy flow, decomposition, or nutrient cycling.

### Final Answer
**Species Composition** is the odd one out with respect to the functional aspects of the ecosystem.

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