FOOD CHAINS AND FOOD WEBS
Food Chain ■ A food chain is the series of organisms showing feeding relationships. A food chain almost always begins with a green plant (producer) which is eaten by an animal (consumer). The arrow means 'is eaten by', and shows the flow of matter and energy along the food chain.
Food Web ■ A network of interrelated food chains in a given area. Because organisms in a habitat generally eat more than one thing, the energy produced in plants connects with several organisms living together. It shows how the loss of one organism has an effect of other organisms in the food web. This is called the interdependence of living things. ■ The following diagram shows the difference between a food chain and a food web.
Tropical Rainforest Food Web The food web of tropical rainforests is highly complicated and many different food chains are interlinked through this biome. However, it can be classified roughly into 4 levels. The first level includes plants (leave s, flowers & fruits), plankton, larvae, spiders and insects. Plankton eaters and insects along with plants are at the second level. The different types of plankton eaters include fish, frogs, possums, bandicoots, birds, echidnas, kangaroos and wallabies. Such types of creatures are abundant in nature and form the diet of those placed above in the hierarchy. Small-sized animal eaters are placed at the third level of food web. Quolls, snakes, platypus, dunnarts, owls, kookaburras, etc. are the small animal eaters at this level. Bigger carnivores like crocodiles, pythons, feral cats, dingoes and feral dogs are placed at the top (fourth) level. Thus, carnivores are at the top and plants at the base of this tropical rainforest food pyramid. For example, dingoes (Canis lupus dingo) find themselves at the top of the food pyramid in Australian rainforests. The different organisms mentioned in 4 levels of the food chain are dependent on each other for obtaining nutrition. Those organisms perched on the topmost tier feed on those at the bottom. Scavengers or decomposing microbes feed on top-level organisms after their death. Organic matter formed as a result of decomposition gets mixed in the soil and thus, food cycle is completed.
Energy Flow in Food Web Flow of energy is a common factor which binds the members of food chain together. Energy originating from the sun is disintegrated through the process of decomposition. Plants use the process of photosynthesis to prepare food for themselves A chemical called chlorophyll plays an important role in the process of photosynthesis. Solar energy is used in the conversion of carbon dioxide and water into sugars Polymerization of sugars facilitates their storage and thus, long-chain carbohydrates are formed. The sulfates, nitrates and phosphates present in soil are used in the preparation of proteins. The proteins and carbohydrates prepared by plants are used as a source of energy by herbivores and eventually carnivores. Biomass goes on decreasing from the base of food pyramid to its pinnacle. The reason behind it is the loss of energy in the environment which results from entropy.