Biogeochemical cycling means

Options

A. cycling of water
B. cycling of nutrients in an ecosystem
C. cycling of energy in an ecosystem
D. cycling of gases between plants and the atmosphere

Answer

**Step-by-Step Solution:**

1. **Understanding Biogeochemical Cycling**:
- Biogeochemical cycling refers to the movement and exchange of chemical substances through the biological (biotic) and physical (abiotic) components of an ecosystem. This includes the cycling of nutrients and elements essential for life.

2. **Components of Ecosystem**:
- In an ecosystem, there are two main components:
- **Abiotic Components**: These are the non-living parts of the ecosystem, such as water, air, soil, and minerals.
- **Biotic Components**: These are the living organisms, including plants, animals, and microorganisms.

3. **Chemical Substances Involved**:
- Key chemical substances that are cycled in ecosystems include:
- Carbon
- Nitrogen
- Oxygen
- Phosphorus
- Calcium
- Water

4. **Process of Cycling**:
- The cycling involves the transfer of these chemical substances between the abiotic and biotic components. For example, plants absorb carbon dioxide (a gas) from the atmosphere (abiotic) and convert it into organic matter (biotic) through photosynthesis.

5. **Types of Cycling**:
- The term "biogeochemical cycling" encompasses various cycles, such as:
- Carbon Cycle
- Nitrogen Cycle
- Water Cycle
- However, it is important to note that energy cycling is not included in biogeochemical cycling.

6. **Conclusion**:
- Therefore, biogeochemical cycling primarily refers to the cycling of nutrients and chemical substances within an ecosystem, highlighting the interconnectedness of living and non-living components.