Department of Conservation (DOC) staff say they feel undervalued by management and will take limited industrial action this week.
More than three-quarters of the department's 2000 staff plan to work to rule from Wednesday.
Public Service Association national secretary Erin Polaczuk said DOC staff had rejected a pay increase as being too low.
Ms Polaczuk said staff wanted a 2 percent pay increase, but were offered only 0.4 percent.
Staff would work only the hours they were paid, except in an emergency.