How can a change in one population affect other populations in a food web?

Changes in one population affect other populations in a food web because everything is connected. For example, lets say there is grass, bunny, and fox. If the grass dies out, then the bunnies have no food and they die. Then the foxes have no food because there are no bunnies. There are many different scenariOS to show this concept. Sorry for the explanation, not the best, but I hope it helped.