Which is not a structural aspect of ecosystem?

Options

A. Productivity
B. Species composition
C. Diversity
D. Life cycle

Answer

To determine which option is not a structural aspect of an ecosystem, we need to analyze the given choices: productivity, species composition, diversity, and life cycle.

### Step-by-Step Solution:

1. **Understanding Ecosystem Structure**: An ecosystem consists of both biotic (living) and abiotic (non-living) components. The structural aspects refer to the physical and biological components that make up the ecosystem.

2. **Identifying Structural Aspects**:
- **Species Composition**: This refers to the variety of species present in an ecosystem. It is a structural aspect because it describes the biological makeup of the ecosystem.
- **Diversity**: This refers to the variety of life forms and their relative abundance in an ecosystem. It is also a structural aspect as it indicates the complexity and richness of the ecosystem.
- **Life Cycle**: This refers to the stages through which organisms go during their life. While it involves the organisms in the ecosystem, it is more related to the processes and functions of those organisms rather than the structure of the ecosystem itself.

3. **Identifying the Non-Structural Aspect**:
- **Productivity**: This refers to the rate at which energy is produced in an ecosystem, typically measured by the amount of biomass generated. Productivity is a functional aspect of an ecosystem, as it relates to the processes that occur within it rather than its structural components.

4. **Conclusion**: Among the options provided, productivity is the one that does not represent a structural aspect of the ecosystem.

### Final Answer:
**Productivity is not a structural aspect of the ecosystem.**

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