An ecosystem is all of the living things in an area. Everything in an ecosystem relies on the other living things around them. When something happens to one part of an ecosystem, it can impact everything else living there. For instance, if a fox relies on eating rabbits and rabbits rely on eating grasses and flowers, but there is a drought and nothing grows for the rabbit to eat, then the rabbits will leave to find food elsewhere and then the foxes won’t have food and they will have to leave the area as well. One thing impacts another.
Sometimes these disruptions are natural, like a drought or a flood. Sometimes they are caused by humans such as fires and cutting down trees and building homes.