What is one effect of a loss of biodiversity in an ecosystem?

To begin, let me discuss the basis of this: trophic levels. All species, be they primary, secondary, tertiary, producers, decomposers, or consumers, fit somewhere along the trophic pyramid. Their role is to keep the ecosystem in balance; if the producers go extinct, the ecosystem will not have food; if the top predators go extinct, population explosions may cause the ecosystem to collapse.

More species in each trophic level indicates a larger menu of food available at every level of the food chain, which increases biodiversity. If a species goes extinct, other species can step in to maintain the trophic level, which in turn ensures the survival of the ecosystem.

Because there are fewer species per trophic level in an ecosystem with low biodiversity, the entire pyramid may collapse if one species disappears because the trophic levels become more dependent on individual species rather than a community of species within each trophic level.

Because of their harsh environment, desert ecosystems aren't very diverse. They have a few species of producer, a few primary and secondary consumers, and a few top predators. For example, if a virus swept through a desert and eliminated most of the coyotes, a top predator, in that area, the populations of jackrabbits, kangaroo rats, mice, and other animals would explode.

A population's need for food increases with its size, so all these consumers will now be fighting for all the available vegetation, and in extreme cases, may even completely deplete it; without any food, the ecosystem will eventually collapse.

The ecosystem's balance might have been preserved if there had been more predators to take the coyote's place, but since coyotes were among the few remaining, the ecosystem was at risk.

One effect of a loss of biodiversity in an ecosystem is a decrease in ecosystem resilience and stability.