Complex sentence: The economy of Duckenfield is dominated by the nearby sugar estate and factory which are the only major employer in the vicinity; any up or down turn in the fortunes of the sugar industry has an immediate and dramatic effect.
Split into simpler sentences: The economy of Duckenfield is dominated by the nearby sugar estate and factory which are the only major employers in the vicinity. Any change in the fortunes of the sugar industry has an immediate and dramatic effect.