Hi again, and thanks for the welcome. In answer to your questions; I live in Nelson which is located at the top of Te Waipounamu or more commonly known as the South Island. Blenheim is an hour and a half away over the hill in Marlborough.
Volunteer workers are becoming more common as our cash strapped Department of Conservation struggles to make ends meet. Doc controls noxious animals (deer, goats, pigs, stoats, rats, possums etc.) in State Forests and National Parks. We used to have government cullers but now it is contractors and volunteers. Doc have Rangers that look after our indigenous forests and also marine, reptile and bird life (and organize the volunteers and contractors).
I think I am right in saying that most pine plantations are now in private hands, often foreign. They usually control animals themselves (or don't bother). Roady