The lion is one of the top predators in its food chain and controls the populations of herbivores, thus maintaining a balance in its ecosystem. In any ecosystem, organisms are arranged according to their role in food chain, from producers to consumers. In many food chains, plants will be at the lowermost level as the top producers, herbivore animals such as deer would be the consumers and would occupy a level next to plants. Predators, such as wolves, tigers, lions, etc., who predate on herbivores would occupy the top place in such a food chain. Each organism controls the population of other organisms through their role in the food chain. Lions control the population of deer and other herbivores by consuming them. Decreases in lion populations would result in increases in deer populations, who will then consume a higher amount of grass. This will continue until deer population runs out of adequate grass. When that happens, deer populations would decrease until they are in equilibrium with grass levels and lion populations. However, there may also be a scenario when consumption by increased deer population results in total lack of producers and failure of food chain. Lions prevent this failure.
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