The food web is an ecological concept that represents the feeding relationship between various organisms in a community. There is a strong relationship between the food web and ecosystem stability.
It is also an important tool that helps with the study of ecological interactions in a community. Such food webs exist in every type of ecosystem and differ only in their member organisms.
The many food chains in an ecosystem do not work independently. No organism in a food chain depends completely on another one either. Instead, they share the available resources and thus are interconnected. This interconnection of organisms between different food chains is called a food web. This food web helps with the stability of an ecosystem.
For example, several herbivores feed on marsh plants and these animals are preyed on by different predators. In another case, carnivores are hunted by other animals that are from a different trophic level.
These cases show that food chains do not function independently. They are interconnected by the same animals that make them and form the food web.
Types of Food Webs
There are three types of food web.
- Topological food web that shows the feeding relationships between organisms.
- The energy flow web shows the quantity of energy passed on from one organism to another.
- The functional web shows the influence of one population on the growth and survival of another population in a community.
Food Web and Ecosystem Stability
A food web is essential for the stability of an ecosystem.
The availability of alternative food sources or pathways makes the system more stable. It helps avoid the extinction of one of the components of a chain which would cause an imbalance. The greater the number of alternatives available in a food chain, the more stable the ecosystem remains.
Larger and complex communities have various factors that can threaten their stability. The growing size of the population is one such example. Despite this, the community can sustain its stability through food webs.
For example, starfish feed on molluscs, allowing other smaller organisms to thrive and increase their population. This way, the decrease in one population is balanced by the increase of another population.
Moreover, the top-down control where the predators of higher trophic levels prey on organisms of lower trophic levels helps maintain the biomass of the lower levels. For eg. It is because the carnivores feed on herbivores which help support the biomass of producers on the earth. Similarly, birds feeding on insects control the leaf damage by them.
References
- Food Web: Concept and Applications | Learn Science at Scitable. (n.d.). https://www.nature.com/scitable/knowledge/library/food-web-concept-and-applications-84077181/
