Ecological Pyramids

Introduction

• Ecological Pyramids are graphical representation of structure & function of ecosystem at trophic levels.
• First described by Charles Elton, hence, also called Elton Pyramids.
• Show relative amounts of parameters like number, energy, biomass etc. across trophic levels.
• First trophic level/Producer forms the base.
• Successive trophic levels are represented by tiers above the base.

1) Pyramids of Number:

• Represent number of individual organisms per unit area at each trophic level.
• It can be either upright (Figure 1) or inverted (Figure 2), depending on type of ecosystem.

2) Pyramids of Biomass:

• Represent amount of energy converted into living tissue at different trophic levels.
• It can also be either upright (Figure 3) or inverted (Figure 4), depending on type of ecosystem.

3) Pyramid of Energy:

• Represent energy flow through trophic levels (Figure 5).
• Always upright.
• An ecosystem without sufficient primary productivity cannot be supported.