Pyramid of Biomass

Ecological Pyramids are a graphical representation of the relationship between different living species at various trophic levels. G.Evylen Hutchinson and Raymond Lindeman offered this. The biomass of each trophic level is determined by the number of individual organisms. Each step or level of the food chain contributes to the formation of a trophic level. Autotrophs or producers occupy the first trophic level.

They transfer solar energy into a form that heterotrophs and consumers can use. Herbivores, or primary consumers, are at the second trophic level, followed by small carnivores, secondary consumers, and larger carnivores, or tertiary consumers.

The amount of energy or biomass available to each trophic level determines the many types of ecological pyramids. To learn more, keep reading.

Ecological Pyramid

The relationship between creatures at different trophic levels in a food chain is depicted graphically or diagrammatically in an ecological pyramid.

Some Important terms Related to it:

Tropic Level

A trophic level is a position occupied by an organism (in a food chain) or a collection of related creatures (in an ecological pyramid). Trophic means “feeding,” hence trophic levels are the order in which organisms are placed based on their feeding patterns. The following are the several trophic levels:

Producers

Plants and other autotrophs are among the most important consumers.

Consumers

These organisms are heterotrophic. Depending on the extent of a food chain in an ecosystem, these organisms can be classed as primary consumers (herbivores), secondary consumers (carnivores), or tertiary consumers (top carnivores).

Decomposers are the secondary or tertiary trophic levels of a detritus food chain.

In the same environment, a species may occupy more than one trophic level at the same time. When a sparrow consumes seeds and fruits, it is a primary consumer; when it eats insects and worms, it is a secondary consumer.

Food Chain

It depicts the transmission of energy from one creature to the next in a population. 

Food web

It refers to a collection of interconnected food chains in a certain locality.

Energy Flow in an Ecosystem

Energy cannot be generated or destroyed, according to the First Law of Thermodynamics, but it can be converted from one form to another. The energy of sunlight, for example, can be converted into food (chemical) and heat energy.

Types of Ecological Pyramids

Based on ecological factors, the ecological pyramids can be divided into three types. This is how they are described:

• Pyramid of Biomass
• Pyramid of Number
• Pyramid of Energy

Biomass Pyramid

At each trophic level, there is a loss of biomass, and each trophic level has a certain mass of living material termed the standing crop. Because there is a loss of biomass, the biomass pyramid is a representation of biomass usage at the following trophic levels in an ecosystem. In terms of biomass, it symbolises the link between producers and consumers.

The dry weight of an ecosystem is easier to determine than the number of organisms or the rate of energy flow at each trophic level. In different environments, the biomass pyramid might be upright or inverted.

Upright Pyramid of Biomass

The straight or upright biomass pyramid can be found in grassland and forest environments, where the biomass of organisms has gradually decreased at successive trophic levels.

Inverted Pyramid of Biomass

• In a pond or a marine ecosystem, the biomass pyramid is inverted.
• Phytoplankton biomass will be lower than zooplankton biomass.
• Zooplankton biomass will be lower than that of primary predators (small fishes).
• The biomass of secondary carnivores (big fishes) is the highest.
• As a result, the phytoplankton occupies the pyramid’s narrow tapering end, while the huge fishes occupy the pyramid’s broad base.

Importance of Ecological Pyramids

• The feeding relationship between the organisms in an ecosystem is represented by ecological pyramids.
• By comparing data collected throughout time in a graphical depiction of an ecosystem, the effects of environmental changes on species can be explored.
• Ecological pyramids depict the efficiency with which energy is transmitted from one trophic level to the next, as well as the productivity of species at various trophic levels.

Limitation of Ecological Pyramids

• Although a considerable amount of energy passes through decomposers in the producers and soil or water-dwelling creatures in an ecosystem, they are not included in ecological pyramids.
• They are based on a simple food chain in an ecosystem; however, food webs, rather than food chains, are more typical in ecosystems.
• They don’t know how to deal with multi-level organisms.
• Seasonal, diurnal, and other fluctuations are not depicted in ecological pyramids.
• The concept of ecological pyramids has given little weight to abiotic energy sources such as trash and humus, despite their incalculable relevance in the ecosystem.

Conclusion

An ecological pyramid is a visual representation of an ecosystem’s trophic structure and function. The producers are at the first trophic level, and they are at the bottom of the pyramid. Above the primary level, more trophic levels (primary, secondary, and tertiary consumers) are added until the pyramid reaches its narrowest point. 

The three major attributes of organisms, namely their numbers, biomass, and energy transfer, are used to create various forms of ecological pyramids in various environments. The broad base depicts a trophic level’s broader extent, while the tapering apex represents the steady drop in number, biomass, and energy at various trophic levels.