Why is biodiversity important to the stability of food webs

The interactions between the many microorganisms, plants and animals is referred to as Biodiversity.

A food web or food chain is a sequence of who eats whom. A simplified sequence involves sunlight, plants, herbivore, omnivore and/or carnivore.

Plants generate food from sunlight, herbivores eat plants, carnivores herbivores, omnivores eat both carnivores, herbivores and plants.

So the biodiversity is important to the stability food webs because, the total nutrient uptake of the multitrophic community, is depends on vertical diversity (i.e. food web's maximum trophic level) and structure (i.e. distributions of species and their abundances and metabolic rates across trophic levels).

Multitrophic community is a community involving species of different trophic levels of the same food chain.

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genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).