Definition and Functions of Ecological Pyramids
The ecological pyramid shows the relationship between various organisms in an ecosystem. The bars forming the pyramid represent different trophic levels and their order, which is decided by who is eaten by whom. It also represents the energy flow. In the pyramid, energy moves in the upward direction initiated by the primary producers or autotrophs which includes plants and algae. Primary producers are present at the bottom of the pyramid. On top of this are the primary consumers who eat the primary producers. On top of which we have the secondary consumers, who consume the primary consumers. This hierarchy goes on forming the pyramid. While the height of the bar measures equal, the width of the bar depends on the quantity of the aspect measured.
Types of Ecological Pyramids
Pyramid of Numbers
This pyramid shows the population present in each trophic level without taking into account their size. It is an upright pyramid with the producers being more in number than any other trophic level.
Unit: number of organisms
Pyramid of Biomass
This pyramid depicts the total mass of organisms at each trophic level. Normally in this kind of pyramid, the bottom would be of the largest size, and it gets smaller travelling up. To attain the biomass of one trophic level we need to multiply the number of individuals in a trophic level by the average mass of one individual in a particular area. The pyramid of biomass solves some issues posed by the pyramid of numbers as the pyramid of biomass can give a more accurate image of the energy contained in each trophic level.
Eg: the duration when the data is procured is very important, the breeding time varies from species to species. Also one must take into account the fact that we cannot measure the ether mass of each organism. This sample is taken for this matter, which may lead to inaccuracies.
Unit: gm-2, Kg m-2
Pyramid of Productivity
This pyramid looks at the maximum energy present at a trophic level and difference in the loss of energy in tropical levels. This pyramid takes into account the fact that the complete energy in one trophic level cannot be made available for the next. This is taken from Lindeman's ten percent law which stated that “ only about 10% of the energy in a trophic level will go towards creating biomass " this means that the making of tissues, leaves, stems only take up 10% of the energy in the next trophic level. The rest goes to the environment as heat or is used up in respiration etc. As we go up the ecological pyramid more and more toxins get accumulated in the organisms.This is known as biomagnification.
This pyramid is not like the other two pyramids, it cannot be greater at the apex and smaller at the bottom. The energy flow in an ecosystem is determined by this pyramid.
Unit: J m-2 yr-1.
Example of a productivity pyramid can be demonstrated through this example
Taking an oak tree, which feeds millions of oak worms. The oak tree is the producer (one tree) will occupy smaller space in the pyramid than the primary consumer which are the worms (millions of insects). This is very unlikely in a biomass pyramid.
Ecological Pyramid Examples
The productivity pyramid is also called the energy pyramid.
Sun is the primary source of energy. Fungi and bacteria are decomposers which can procure nutrients from any trophic level by breaking down dead and decaying organisms. These nutrients return to the soil and ate taken up by plants.
“Taking into consideration the total amount of energy that the primary producers contain, it is indicated by 100%, as we go up level one 90% of the energy is used up. The primary consumers end up with 10% of the starting energy. 10% of this 10% is lost while transferring it to the next level. As a result of which the apex, occupied by the predators will only reactive 0.01% of the initial energy. This inefficiency results in the productivity pyramid being upright.
The Function of the Ecological Pyramid
The ecological pyramid represents the inefficiency of energy transfer, the effects of how a change of numbers in one trophic level affects the trophic levels above and below it. It also shows the food patterns of various organisms in multiple ecosystems. The data that has been collected over the years can be compared giving us an idea of how the changing environment affects an organism, which will paint a vivid picture of how the ecological conditions are worsening and actions can be accordingly taken.
Related Biology Terms
Trophic Level: the position where an organism is placed in the ecological pyramid depending on what they feed on. Eg producers, primary consumers.
Species: a group of organism that has characteristics in common, and can repopulate among themselves.
Ecosystem: a group of living organisms living together with non-living entities surrounding them. Through the exchange of nutrients and energy living organisms interact with the physical environment.
Food Web: a system of the interdependent food chain. The difference between the food chain and the food web is that in a food web an organism can occupy any trophic level wherein a food chain they have specific positions.
FAQs on Different Types of Ecological Pyramids
1. Are there any limitations of ecological pyramids?
Ecological pyramids help us to get a graphical presentation of bio productivity that is happening at the different trophic levels in a particular ecosystem. According to the different classifications depending on which the trophic levels are picturised, different species take the positions of predators in each particular trophic level. Different species have been classified as different types of consumers considering the external influential factors as constant. Considering the type of behaviour of different species they have been classified as producers, primary, secondary, and tertiary consumers.
But nature is not constant and the behaviour of different species is also not constant. For example, a particular type of species whom we have identified as primary consumers can also act as secondary consumers. Thereby assigning the role of primary consumers to the species at a particular trophic level is not justified.
Also, there are chances of seasonal and climatic changes influencing the behaviourism and lifestyle of the species. The limitations of ecological pyramids are that these are only applicable to the system of simple food chains. The pyramids do not take into account that there is a possibility of different types of species exhibiting the behaviourism of different types of consumers at different levels. Also, the pyramids do not take seasonal and climatic variations into account that can hugely impact the lifestyle of the species.
2. What are the facts explained by the ecological pyramids?
An ecological pyramid is a kind of graphical presentation that is dependent on the system of simple food chains. Ecological pyramids are divided into different trophic levels that help us to understand the relationship between different kinds of species that are part of the natural ecosystem.
The graphical presentation of the ecosystems is also very important to understand the flow of energy that is occurring at different trophic levels of the pyramids due to the distinguishable behaviorism of the producers and consumers. The consumers are also categorized into different types like primary, secondary, and tertiary consumers and ecological pyramids help us to understand the concept of energy flow when a particular animal belonging to a particular trophic level of the ecological pyramids consumes another animal.
3. What is the importance of understanding the concept of ecological pyramids?
Understanding the concept of ecological pyramids can help the students to have a detailed knowledge of the natural food chains that take part in our ecosystem. The concept will help them to understand the different kinds of behaviorism exhibited by the different species and how the life cycle takes place in nature. In order to understand the concept of the food chain, the students need to have a good understanding of the lifestyle of different species and how they survive by consuming other species.
Students who want to pursue their higher academics in the field of microbiology or zoology should have a clear knowledge of the foundational concepts of biology. The different kinds of food chain systems and various ecological systems fall under the category of foundational concepts of biology. That is why the graphical representation of the relationships between different species shown by the ecological pyramids is very important.
4. How does the graphical representation of ecological pyramids help people to infer various information about different species and their behaviorism?
The graphical representation of ecological pyramids is data-driven and the statistics and analysis of the behaviorism shown by different species also play a very important role. Ecological pyramids are structured on the basis of the actual food chain systems that take place in the ecological system.
The visible representation of the ecological pyramids helps us to define the different trophic levels with the help of bars and also helps us to represent the energy flow due to the consumption of the species by their predators. Biological pyramids act as easy graphical and visual representations of the relationship between the different species belonging to the trophic levels.
5. What is the easiest way to have a detailed understanding of ecological pyramids?
There are different types of ecological pyramids based on the individual number of species, biomass and energy flow. To understand the concept of ecological pyramids, it is very important for the students to analyse the basic characteristics exhibited by different kinds of species. The basis of the ecological pyramids is a simple food chain system.
The concept of energy flow can also be understood easily if the students can understand the basic difference between the producer and the different types of consumers belonging to nature. When a particular animal belonging to a definite trophic level consumes another animal of a different trophic level, a particular amount of energy is also consumed by the former consumer. The students can also refer to the various articles published on the website of Vedantu that provides them with a detailed discussion of all the important chapters that are included in their biology syllabus.
