Aquatic ecology and Biodiversity

Unit 2- Ecosystem ecology

2.3.2. Food web
The transfer of energy through different tropic level in an ecosystem may follow several pathways. Each path way that transfer energy form a given plant or plants through a given series of consumer is called food chain. Food webs are very important in maintaining the stability of an ecosystem. When one type of herbivores animal becomes extinct, the carnivore predating on this type may eat another type of herbivore.
The combination of all food chain in a given community or ecosystem is called food web. The interlocking of many food chains is called food web. Food web is non linear flow of energy. Food web is a set of interconnected food chains by which energy and materials circulate within an ecosystem. The food web is divided into two broad categories viz., the grazing web, which typically begins with green plants, algae, or photosynthesizing plankton and the detritus web, which begins with organic debris. These webs are made up of individual food chains. In a grazing web, materials typically pass from plants to plant eaters (herbivores) to flesh eaters (carnivores). In a detritus web, materials pass from plant and animal matter to bacteria and fungi (decomposers), then to detritus feeders (deprivers) and then to their predators (carnivores).
Simple food chains are very rare in nature. This is because each organism may obtain food from more than one trophic level. In other words, one organism forms food for more than one organism of the higher trophic levels.