Edaphic factor refers to :

Options

A. Water
B. Soil
C. Relative humidity
D. Altitude

Answer

### Step-by-Step Solution:

1. **Understanding Edaphic Factors**:
- Edaphic factors are a subset of abiotic factors that specifically relate to the soil and its properties. They play a crucial role in shaping ecosystems.

2. **Classification**:
- Edaphic factors are classified under abiotic factors. Abiotic factors are non-living components of the environment that affect living organisms.

3. **Components of Edaphic Factors**:
- Edaphic factors include various soil characteristics such as:
- **Soil Texture**: The size of soil particles (sand, silt, clay) which affects water retention and aeration.
- **Substratum**: The underlying layer of soil or rock that influences the types of plants and organisms that can thrive.
- **Topography**: The arrangement of the natural and artificial physical features of an area, which can influence drainage and sunlight exposure.
- **Mineral Composition**: The types and amounts of minerals present in the soil, which can affect nutrient availability.
- **pH Level**: The acidity or alkalinity of the soil, which influences nutrient solubility and availability to plants.

4. **Impact on Ecosystems**:
- These edaphic factors influence the distribution of organisms, their interrelationships, and the rate of decomposition in an ecosystem.

5. **Conclusion**:
- Based on the understanding of edaphic factors, the correct answer to the question is that edaphic factors refer to soil-related characteristics.