What does the base tier of the ecological pyramid represent ?

Explanation

### Step-by-Step Solution:

1. **Understanding the Ecological Pyramid**: The ecological pyramid is a graphical representation that illustrates the relationships between organisms at different trophic levels in a food chain.

2. **Types of Ecological Pyramids**: There are three main types of ecological pyramids:
- Pyramid of Number
- Pyramid of Energy
- Pyramid of Biomass
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