Why does biodiversity contribute to a habitat's sustainability? The more plants and animals in a habitat, the greater the biomass, which is how habitats store energy. The greater the number of species, the more competition there is for food between predators, which sustains their populations. Healthy ecosystems clean our water, purify our air, maintain our soil, regulate the climate, recycle nutrients and provide us with food. ... Biodiversity is the key indicator of the health of an ecosystem. A wide variety of species will cope better with threats than a limited number of them in large populations Healthy ecosystems clean our water, purify our air, maintain our soil, regulate the climate, recycle nutrients and provide us with food. ... Biodiversity is the key indicator of the health of an ecosystem. A wide variety of species will cope better with threats than a limited number of them in large populati