Answer: Top predators, or tertiary consumers can also be keystone species. ... Without their predator, the populations of these herbivores grows out of control as they eat all their food source, the producers. Like changes in other trophic levels, without the producers, the entire ecosystem can collapse.
Explanation: Food webs illustrate energy flow from primary producers to primary consumers (herbivores), and from primary consumers to secondary consumers (carnivores). ... Under top-down control, the abundance or biomass of lower trophic levels depends on effects from consumers at higher trophic levels. So yeah!