Ecosystems are organized in a state of balance where species coexist with other species on harmony.If something happens in an ecosystem it shift from a state of balance to a state  of imbalance.Ecological imbalance is when a natural or human -caused disturbance disrupts the natural balance of an ecosystem.A disturbance is any change that causes a disruption in the balance of an ecosystem.Examples of natural disturbances are volcanic eruptions,floods,or natural fires.Examples of human caused disturbances is are the introduction of a new species ,logging a forest,pollution,or over hunting of a species.