An ecosystem consists of interacting biotic and abiotic components. It contains food web, a hierarchical arrangement of organisms showing matter and energy flow. The complexity of food web is an indicator of a healthy ecosystem. A food web consists of organisms divided into several trophic levels depending on their food choices. These trophic levels include the producers, primary consumers, secondary consumers, etc. In a healthy ecosystem, each of these trophic levels will include a number of organisms. For example, deer is not the only primary consumer, there are a number of other herbivores. Similarly, these primary consumers will have more than one predator. Thus, a large number of organisms at different levels, interacting with each other represent a healthy ecosystem. Such healthy complexity of food web is only possible if there is sufficient biodiversity in the given ecosystem. Limited biodiversity keeps the food web simple and more prone to perturbations, which is not a sign of a very healthy ecosystem.
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