A food web is an illustration that depicts the feeding links within a community. It also refers to the movement of dietary energy from plants to herbivores and then to predators. Normally, food webs are made up of a number of interconnected food chains. Each food chain is a descriptive graphic with a succession of arrows pointing from one species to the next, illustrating the transfer of food energy from one feeding group to the next. This article will explain to you about Food Web which will be helpful in preparing the Environment syllabus for the UPSC Civil service exam.

Food Web - Concept

• A food web is a thorough representation of the species in a community and their relationships with one another.
• It demonstrates how energy is moved up interconnected food chains.
• A food web differs from a food chain in that the latter is a linear structure depicting a succession of animals in which each species is eaten in turn by another species, but a food web is a more intricate network of who eats who in a given environment.
• If any link in the intermediate food chain is removed, the chain's subsequent links will be severely impacted.
• Most species in an ecosystem have more than one food source due to the food web, which boosts their chances of survival.
• For instance, grasses can provide food for rabbits, grasshoppers, goats, and cows.
• A herbivore, on the other hand, maybe a food source for a variety of carnivorous species.
• A food web is depicted in the diagram below. Arrows in food webs point from a devoured organism to the organism that eats it.

Food Web

Trophic Levels in a Food Web

Primary Producers

• In general, primary producers include photosynthetic organisms such as plants and algae.
• Using solar energy, they are able to manufacture food on their own.

Primary Consumers

• The organisms that derive their energy by devouring the main producers are known as primary consumers.
• Herbivores are thought to be the principal consumers.

Secondary Consumers

• For food, secondary consumers prey on primary consumers.
• They'll be carnivores or omnivores. They are then consumed for food by the tertiary consumers.
• Decomposers and detritivores play an important role in the food chain. The apex predators are at the highest level in the food web.

Energy Flow in a Food Web

• When one creature feeds another and obtains energy-rich molecules from its prey's body, energy is transmitted between trophic levels.
• However, these transfers are inefficient, and as a result, the length of food chains is limited.
• Some of the energy that enters a trophic level is stored as biomass, which is a component of organisms' bodies.
• As only energy stored as biomass can be eaten, this is the energy available to the next trophic level.
• As a general rule, only around 10% of the energy stored as biomass in one trophic level (per unit time) ends up being stored as biomass in the following trophic level (per unit time).
• The length of food chains is limited by this pattern of fractional transfer; after a certain number of trophic levels, usually three to six, there is insufficient energy flow to support a population at a higher level.

Applications of Food Webs

To depict species interactions (direct relationships)

• Food webs are used to describe the nutritional relationships among species in a community.
• To describe the relationships between species, food webs can be created.
• All species in food webs can be classified as either basal (autotrophs, such as plants), intermediate (herbivores and intermediate level carnivores, such as grasshoppers and scorpions), or top predators (herbivores and intermediate level carnivores, such as grasshoppers and scorpions) (high level carnivores such as fox).
• We can simplify and explain the relationships between these species by grouping them into distinct functional groups or tropic levels.

To illustrate indirect interactions among species

• When two species do not interact directly with each other, but are impacted by a third species, it is called indirect interaction.
• Species can influence each other in a variety of ways. One example is keystone predation, which was proved by Robert Paine in a rocky intertidal zone experiment.
• Predation can affect competition among species in a food web, according to this study.
• Mussels, barnacles, limpets, and chitons can all be found in the intertidal zone. The predator starfish Pisaster preys on all of these invertebrate herbivores.
• Paine discovered that when he manually removed starfish from experimental plots while leaving other areas undisturbed as control plots, the number of prey species in the experimental plots dropped (a loss of 7 species) two years later, while the total number of prey species in the control plots remained the same.
• In the absence of the predator starfish, he reasoned, several mussel and barnacle species (which were superior competitors) would eliminate other species, reducing total diversity in the ecosystem.
• Starfish predation lowered the population of mussels, allowing other species to spread and thrive. Keystone predation is the term for this form of indirect interaction.

Indirect Interactions Among Species

Food Chain vs Food Web

Significance of Food Web

• Many organisms in the lower trophic level of other food chains can be fed by higher trophic level members.
• The presence of a complex food web promotes the ecosystem's stability.
• It has trophic levels or populations of several species.
• Food webs prevent famine and aid in the population growth of endangered animals.
• There are numerous interrelated food networks.
• Food webs are useful for understanding how population disruptions caused by overhunting, poaching, global warming, and habitat destruction lead to food scarcities and extinction.

Conclusion

Plants are the cornerstone of all ecosystems and food chains, supplying nourishment and oxygen for survival and reproduction. Food webs are useful tools for understanding this. Food webs are useful for understanding natural selection because they demonstrate the hierarchy of species, with carnivorous, omnivorous, and tertiary animals at the top of all food chains.