Ecological Pyramid – Definition, Types, Importance, Limitations

An ecological pyramid is a graphical representation of the relationship that every living creature present at different levels of the ecosystem shares with each other. Ecological Pyramids represent the different forms of bio-productivity of an ecosystem i.e. how much biomass, energy, or number of individuals each trophic level accounts for. In this article, we will learn about the ecological pyramid types, their significance, and limitations.

What is an Ecological Pyramid?

The ecological pyramid is also known as a food pyramid, trophic pyramid, or energy pyramid, and even the Eltonian pyramid as the concept of such pyramids which depict numbers was proposed by Charles Elton in the year 1927. Then came Bodenheimer in 1938 who proposed the pyramid structure for biomass and in 1942 Hutchinson and Linderman proposed the pyramid for productivity.

The pyramid is framed based on the number of individuals, energy, and biomass, and very much like the name recommends, these are shaped as a pyramid. The various kinds of ecological pyramids depend on how much energy or biomass or individuals are accessible to each trophic level.

The bottom of the pyramid, usually the broadest part is occupied by the producers followed by the primary consumers at the next level, then the secondary consumers, and then tertiary consumers or the organisms placed at the top of the food chain at the topmost level. The ecological pyramid is additionally used to make sense of how different living beings in an environment are connected with each other. Also, it shows who is consumed by whom, while likewise showing the flow of the energy.

Ecological Pyramid Diagram

The diagram below depicts the ecological pyramid.

Features of the Ecological Pyramid

The following are the characteristics of an Ecological Pyramid:

• The ecological pyramid comprises two to four layers.
• Organisms that are dependent on the same type of food sources are placed at the same level.
• The producers are situated at the lowest level of an ecological pyramid with a huge population.
• The apex predators exist at the topmost level of an ecological pyramid with a relatively smaller population.
• The pointed shape of the pyramid is due to the fact that the supply of energy or biomass becomes lesser with each passing level of the pyramid.
• In the case of the pyramid of numbers, the topmost level will have a lesser number of individuals but their relative body size and volume increase.

Ecological Pyramid Types

The ecological pyramid is of three types; the pyramid of numbers, the pyramid of biomass, and the pyramid of energy.

Pyramid of Number

The Pyramid of Number denotes the total number of living individuals at various trophic levels in an ecological system. The producers are at the base and top carnivores at the topmost level in this pyramid.

The pyramid of numbers can be both upright and inverted.

• The upright pyramid has the largest number of producers at the base and their numbers keep on declining with each passing level like pond or grassland ecosystem.
• In the inverted pyramid, the base pointed with a lesser number of producers whereas the topmost level will have the largest number of individuals as the size and food consumption of organisms in each level will decrease i.e. in this system one individual producer can support many primary consumers, similarly, one primary consumer can support many secondary consumers, and so on. This type of pyramid is seen in the case of a parasitic food chain.

Pyramid of Biomass

The ecological pyramid that is made by considering the amount of biomass that is produced by the living system of each trophic level is represented by the pyramid of biomass. The pyramid that demonstrates the total weight of every trophic level in a specific food chain in an ecosystem is the biomass pyramid.

Like the pyramid of numbers, the pyramid of biomass can be both upright and inverted.

• Forests and grasslands ecological systems are instances of upstanding biomass pyramids as the number of producers is more in number.
• The ocean ecosystem is an example of an inverted pyramid as a large number of zooplankton are dependent on a lesser number of phytoplankton. Dependent on the trophic level of an ecosystem, only 15% to 20% of biomass per level goes to the following level. 

Pyramid of Energy

The ecological pyramid which is formed by determining the flow of energy from one trophic level to another is known as the pyramid of energy. The producers situated at the base of the pyramid of energy have the highest amount of energy and the topmost consumer at the top has the least amount of energy. 

The pyramid of energy is always upright. This pyramid addresses the complete energy content of each trophic level in an ecological system.

• The base of this pyramid i.e. producers has the most amount of energy acquired from the sun fixed by the help of photosynthesis.
• The flow of energy in this pyramid proves that energy can neither be created nor can be destroyed given by the law of thermodynamics.
• However, as indicated by Lindeman’s 10% regulation law, only 10% of the energy gets transferred from one level to another as almost the 90% is lost as heat energy is used in breathing, some are utilized in physiological cycles, and the rest is utilized by decomposers.

Importance Ecological Pyramid

The ecological pyramid is important in a biological system due to the following reasons:

• An ecological pyramid takes into account the dietary patterns of various living organisms.
• The ecological pyramids take into account the number of living creatures in an ecosystem.
• It gives clarity of how much energy moved to start with one trophic level and then onto the next level of the ecosystem.
• It gives data about the biodiversity of a region.
• The ecological pyramid is framed based on the food-consumer relationship. 
• If the food chain order is disturbed, the biological pyramid will be disturbed and the entire environment will be seriously harmed.
• It helps in keeping up with equilibrium and helps in checking the entire state of a biological ecosystem.

Limitations of Ecological Pyramid

Following are the limitations that the system of ecological pyramid possesses;

• The ecological pyramid does not take into account the saprophytes and treats them as non-living components of the environment, despite the fact that they have a significant part in maintaining the equilibrium of the environment.
• There is no inclusion of diurnal or occasional varieties in this pyramid, the idea of environment or seasons is totally unassumed here.
• The ecological pyramid is just relevant in the event of straightforward food chains not considering the complex food webs.
• This pyramid specifies nothing about the pace or speed by which energy moves from one trophic level to the next trophic level.
• Significant sources of energy like litter and humus are totally overlooked in the ecological pyramid despite the fact that their significance in the environment is unrivaled.
• Similar species existing at various levels in a pyramid are not considered.

Conclusion – Ecological Pyramid

In conclusion, ecological pyramids provide valuable insights into the structure and functioning of ecosystems. By visualizing the relationships between different trophic levels, we gain a deeper understanding of how energy, biomass, and population numbers are distributed within ecosystems. These ecological pyramids serve as powerful tools for ecologists to analyze and compare various ecosystems, highlighting their diversity and complexity. As we continue to study and appreciate ecological pyramids, we also recognize the importance of maintaining balance and harmony in our natural world to sustain life for future generations.

FAQs on Ecological Pyramid

What are the Three Types of Ecological Pyramid?

Ecological pyramids can be of three types depending on the: Number, Biomass, and Amount of Energy

What are the 4 Levels of Ecological Pyramid?

The 4 levels of ecological pyramids are – Primary producers, Primary consumers, Secondary consumers, and Tertiary consumers.

What do the Three Types of Pyramids Illustrate?

The 3 pyramids of ecology illustrate the relationship between various living organisms with each other and with the environment. They depict – biomass, number of organisms, and energy in each trophic level.

Give an Example Representing the Inverted Pyramid of Numbers.

Example of the inverted pyramid of numbers: Tree (Base – Producer) –> Birds (level 1 – Primary consumer) –> Bugs (level 2 – Secondary consumer) –> Microbes (level 3 – Tertiary consumer)

What is the Role of Decomposers in Ecological Pyramids?

The decomposers break down dead organisms into simpler inorganic materials which the primary producers can use as nutrients.

What is the Impact of Deforestation on the Ecological Pyramid?

Deforestation disrupts the ecological pyramid by reducing the habitat and food sources for primary producers, leading to a decline in primary consumers and subsequent trophic levels.

Which Ecological Pyramid is Always Upright?

The pyramid of energy is always upright.