An ecological pyramid is a graphical representation of different living organisms at different trophic levels. It was given by Raymond Lindman and G. Evelyn Hutchinson. These pyramids are shaped like actual pyramids with base broads and narrow down at the apex. The first trophic level is producers and the next topic level is primary consumer and so on. Graphical representation of the ecological pyramid shows a relationship between living beings at different trophic levels.
[Image 1 – Ecosystem Energy Transfer]
Ecological pyramids also explain how organisms in ecosystems are related to one another. The energy flow in these pyramids is from bottom to top which means the transfer of energy from autotrophs to primary producers rather than primary consumers and so on. A species can occupy more than one trophic level. For example, a sparrow is a primary consumer when eating fruits, seeds, etc. It comes in the category of the secondary consumer when it eats worms and insects. Producers are more in number and biomass than herbivorous. Further herbivores are more than carnivorous and lower trophic level energy e is more than higher trophic level.
[Image 2– Pyramid of number]
It represents the number of organisms in each trophic level. The pyramid of numbers is always upright but in situations like the detritus food chain, it doesn't show an upright position. As higher up the pyramid the number of organisms decreases. The producers are in large numbers so it is present at the bottom.
[Image 3– Pyramid of biomass]
This ecological pyramid shows different amounts of biomass produced by each trophic level. The pyramid of biomass is always upright except in oceans because large numbers of zooplankton depend on phytoplankton. The producers have the highest biomass in this pyramid and then primary consumers have less biomass than producers. Similarly, secondary consumers have less biomass than primary consumers and at least biomass is present at the top of the pyramid. The pyramid of biomass in a sea is also inverted because the biomass of fish exceeds phytoplankton.
[Image 4– Pyramid of energy] The pyramid of energy is always upright because energy flow in a food chain is unidirectional and on increasing trophic levels some energy is lost in the environment. This pyramid of energy shows the transmission of energy from consumers to producers.
Here is the following importance of the ecological pyramid.
1. This pyramid shows the feeding of organisms in different ecosystems.
2. It shows the productivity of energy transfer.
3. With the help of this ecological pyramid it is easy to monitor the condition of the ecosystem.
4. These pyramids show how much energy is transferred from one level to another.
5. This pyramid shows how one organism is dependent on another in a particular ecosystem.
1. The ecological pyramid does not include saprophytes. It assumes them as necessary or important in the ecosystem.
2. This ecological pyramid doesn't mention diurnal and seasonal variation.
3. This ecological pyramid is appreciable in a simple food chain that sometimes never exists in nature.
4.The ecological pyramid does not explain the food web.
5. The concepts like hummus are ignored in this pyramid.
6. If the same species present at a different level in a pyramid then it is not taken as deliberation.