Food Chains and Food Webs

The trophic level is an organism’s position on the food chain. This article covers the different elements involved in the food chain.

Food Chain

The food chain is a sequential sequence of organisms in which nutrition and energy are passed from one level to the next. This energy transfer happens when one organism consumes another in the food chain

Producers act as the base organisms in the food chain while the food chain ends with the decomposers. The flow of energy follows a specific path in the food chain

In an ecosystem, organisms are categorized in different levels as primary producers (PP) such as plants, primary consumers (PC) such as insects, secondary consumers (SC) such as snakes, and tertiary consumers (TC) such as hawk. These levels of organisms further form a pyramid in the ecosystem. These pyramids may be upright or upside-down, depicting the flow of energy between different levels of organisms

When decomposers act as the starting organism, the food chain is called the detritus food chain. This food chain does not depend on the Sun. Example of a detritus food chain is: Dead organic matter → Bacteria → Earthworms

The grazing food chain is a food chain in which the organisms get their energy from photosynthesis. Green plants are the producers and can undertake photosynthesis, hence they are at the top of the grazing food chain. The energy is then transferred from green plants to herbivores. The Sun is the ultimate or principal source of energy transmission in a grazing food chain. Example of a grazing food chain is: Plants → Goat → Lion

Food Web

The Food web shows the transfer of energy between different organisms. Interconnected food chains form food webs. The food chain and food web together form a balanced ecosystem

Each organism is usually consumed by two or more different organisms, which in turn are consumed by several other organisms. Rather than a straight line in the food chain, the connections are often displayed as a series of branching lines in a food web

Elements of Food Chains and Food Webs

Elements in Food chains and food webs include producers, primary consumers, secondary consumers, and tertiary consumers

Autotrophs such as plants and algae acquire the energy present in the sun and convert it into chemical energy. The energy is further transferred when autotrophs are consumed by heterotrophs such as insects, birds, fishes and finally decomposers

Herbivores including goats, cows, and rabbits are only plant-eating organisms. Carnivores such as lions, hyenas, and tigers only consume other animals. Omnivores such as birds, dogs, and humans can eat both plants and animals

Energy transfer in a food chain

Interactions among the different environment components result in an exchange of energy from one element of the system to another

The transfer of energy from one level to another leads to the loss of energy to the environment

Leafy plants in an earthly biological system catch around 1% of the sun’s energy that falls on their leaves and convert it into food energy

So, when primary consumers consume the green plants, large amounts of energy are lost as heat to the environment. Some go into digestion and work, and the remaining goes towards growth and reproduction

An average of 10 percent of the food eaten is revolved into its own body and made available for the following level of consumers

Thus, ten percent can be held as the average value for the amount of organic matter present at each step and reaches the following level of consumers. This energy transfer from one level to another is known as Linderman’s Ten percent Law

The energy flow diagram depicts that

The flow of energy is unidirectional.

Energy accessible at each trophic level decreases gradually

Trophic Levels

Autotrophs or producers trap the Sun’s energy to make their food. So, autotrophs occupy the first trophic level

The herbivores or the primary consumers approach at the second, small herbivores or the optional shoppers at the third trophic level

Large carnivores or tertiary buyers occupy the fourth trophic level

Since little energy is accessible for the following level of consumers, food chains typically consist of just three or four steps

So, usually, there are higher numbers of individualities at the lower trophic levels of an ecosystem, the maximum number being the producers

Unknowingly, some dangerous chemicals enter our bodies through the food chain

Chemicals such as pesticides are moreover washed down into the soil or the water bodies

These are soaked by the plants and water and minerals from the soil

From the water bodies, these are taken up by underwater plants and animals

Such chemicals aren’t degradable and accumulate gradually at each trophic level

Humans are typically at the top level in any food chain, where the maximum concentration of these chemicals gathers in our bodies. This phenomenon is understood as biological magnification

Conclusion

Food chains and food webs form an integral part of the ecosystem. The food chain is a linear sequence of organisms, whereas a food web is a chain of multiple food chains. Energy cannot be created or destroyed in the ecosystem but only transformed. In the terrestrial form of the ecosystem, the Sun acts as the energy source. Energy transfer occurs according to the 10 percent energy law between levels of organisms, while 1 percent of energy is received at the primary level of organisms from the Sun. Food chains and food webs check the ecosystem’s health by maintaining the organism’s population in the ecosystem. The absence of any organism imbalances the interlinked food chains and may have a reverse impact on the ecosystem.