Ecological Pyramids

Introduction

Graphically representing biomass in a unit area at multiple trophic levels is a pyramid of biomass. It depicts the link between biomass and trophic level and the biomass available in each trophic level of an energy community at any given time.

Ecological Pyramid Definition

The ecological pyramid, also known as the Estonian pyramid, depicts the link between the populations, biomass, energy, and bio productivity of different trophic levels in an ecosystem. The ecological pyramid definition depicts the energy flow in the system.

A biomass pyramid depicts the total live biomass or biological matter present at various trophic levels in an ecosystem. Biomass is the mass of living things present at each trophic level in a given sample size. There are two methods to represent it: dry weight in grams or calories per unit area. A bomb calorimeter is used to determine biomass.

The location of a living thing in a food chain is referred to as its trophic level. The bottom of a biomass pyramid is producers (1st trophic level), followed by herbivores (primary consumers), and eventually carnivores (secondary and tertiary consumers).

The biomass pyramid depicts the flow of energy from producers to consumers. Only 10% of energy is transferred to the next trophic level. The rest goes to metabolic processes or is excreted.

Examples of the Pyramid of Biomass

A biomass pyramid depicts the efficiency of energy transmission at each trophic level. It might be inverted or upright. Inverted biomass pyramids can be seen in marine habitats. To understand why there is a difference between biomass pyramids in the terrestrial and marine ecosystems, consider the examples of terrestrial and marine biomass pyramids. The link between biomass, productivity, and energy at different trophic levels is shown by an ecological pyramid.

Primary producers are often depicted at the bottom of the diagram, with apex predators at the top. The number of producers (primarily grasses) is always at its highest in a grassland ecosystem, followed by diminishing numbers at the second trophic level (herbivores), third trophic level (carnivores), and the smallest number of apex predators.

Pyramid of Biomass of a Grassland Ecosystem

In a grassland ecosystem, the pyramid of biomass is upright. On land, most ecosystems feature upright biomass pyramids with a large base of primary producers and a smaller trophic level perched on top, thus the upright pyramid of biomass. Autotrophs (producers) have attained their maximum biomass. At the next trophic level, primary consumers have less biomass than producers.

Other customers, such as secondary and tertiary clients, are lower than core customers. At the top of the pyramid, there is relatively little biomass. The food chain’s top predators have the least biomass, such as foxes and eagles. In terrestrial ecosystems, the Pyramid of Biomass is so upright.

A common approach for estimating the biomass pyramid is gathering all organisms in each trophic level separately and weighing them dry. Each trophic level has a fixed amount of living material called a standing crop, which is measured as the mass of live creatures (biomass) or the number of organisms in a unit area at any one moment. Population decrease from the bottom to the top of an erect pyramid of numbers.

Grassland and pond environments are the most likely places to find this pyramid type. The grass is the lowest trophic level in a grassland environment due to its abundance. The biomass pyramid represents the total mass of organisms at each trophic level. The biomass of primary consumers (herbivores) is highest near the base of the grassland ecosystem, followed by that of secondary consumers (carnivores).

Pyramid of Number in a Grassland Ecosystem

Herbivores like rabbits, rats, and other small animals have the most biomass, followed by grasses. Tertiary consumers (birds, lizards, snakes, and so on) follow secondary consumers (owls, lizards, snakes, and so on) (eagle, etc.) Since biomass is computed by multiplying the biomass of organisms by the number of species present at each trophic level, we can see that grass biomass is significantly larger than that of primary consumers. The biomass of secondary and tertiary consumers falls progressively.

Biomass can rise at higher trophic levels in the aquatic system. The food chain in the ocean, for example, often starts with phytoplankton and ends with predatory fish, which have the largest biomass.

Producers

There are many producer organisms, but they all have one thing in common. Producers capture the sun’s energy through photosynthesis to produce food from carbon dioxide, water, and nutrients from the soil and store it for future use. Producers also can be found in grasslands, including grasses, shrubs, trees, lichens, and bacteria.

Consumers

Grassland ecosystems are home to numerous plants that offer their energy to various animals and microorganisms. Some grassland producers include trees, ground shrubs, grasses, and cyanobacteria. The plants in a grassland ecosystem can fully use the sun’s energy for metabolism by capturing it in large, photosynthetic reaction centres with light-harvesting complexes. Everyday consumers in a grassland ecosystem include arthropods, fungi, bacteria, and other plants.

Decomposers

In addition to the numerous components of an ecosystem, some organisms exist on its outskirts. These organisms are called decomposers, and they are critical to system sustainability. Through decomposition, organic matter is broken down into smaller parts and then taken up by other organisms to recycle. Decomposers do more than recycle — when done properly, they make nutrients available for new plant growth.

Biomass Pyramid of a Tree Ecosystem

As opposed to the number pyramid, the biomass pyramid better represents energy flow. For example, in a tree ecosystem, the number pyramid does not appear to be perfect because one oak tree sustains hundreds of insects, which are then consumed by a smaller number of birds. Caterpillars/insects (primary consumer) Oaktree (producer) Woodpecker (Secondary consumer)

Pyramid of Biomass of a Marine Ecosystem

The aquatic ecosystem’s biomass pyramid is inverted. The biomass of primary producers is substantially lower than that of zooplanktons, which is lower than that of small and large fish, which have the highest biomass.

You might be wondering how this is feasible and how the ecosystem can function with so few phytoplanktons. Because phytoplanktons have a higher reproducibility rate and shorter lifespan, they regularly replenish to meet the increased demand of zooplankton and larger fish, even though their quantity is lower at any given moment.

Conclusion

We learned about the diagrammatic representation of the amount of organic material (see biomass) contained in a particular environment at increasing trophic levels of a food chain, measured in grams of dry mass per square meter (g m2). Each rung of the food chain sees a drop in biomass.