A Food Chain Without Herbivores and Carnivores. Without the herbivores, the producers would be free to grow. Producers don't need the herbivores or carnivores to make their own food and energy. They are self-sustaining, and they can't exhaust their food source.
And as well as if there are only producers and no herbivores or carnivores then producers grow on continuously and there will not be the utilization of it. so there can't be a food chain without herbivores or carnivores.