My example is a grassland. Things you might find in a "healthy" grassland are rabbits, foxes, and grass. Rabbits need grass to survive so if there's no grass a rabbit can't live. And if the rabbits died foxes won't a meal either. And grass needs soil and water to live.
So since ecosystems/habitats are "fragile" we should protect them which could result to protect animals which could make us to protect the earth from disaster.