What will happen if we kill all the organisms in one trophic level?

If we kill all the organisms at one trophic level then the food chain would end and ecological balance would be affected. If the herbivores are killed, then the carnivores would not be able to get food and would die. If carnivores are killed, then the population of herbivores would increase to an unsustainable level. If producers are killed, then the nutrient cycle in that area would not be completed. For example, in a food chain grass is eaten by a buffalo and buffalo is eaten by a lion. If all the lions in the population were to be removed, the number of buffalo will increase and this will ultimately lead to over-grazing. Over-grazing can lead to barren land which will ultimately lead to soil erosion. Also, all buffalo will die as there is no grass for them to eat.