Who is to blame for deforestation in New Zealand?

Answer 1

Both Humans and natural fire are the causes of forest fires. The Great Otago Fire of the 1300's was at least coincident with the arrival of the Maori, and in the North Island there is clear evidence via palynology of cut-and-burn practices.

European settlers have created de-forestation. In the far north there is evidence of pre-human natural disasters, and also in the central North Island.

The Taupo Volcano has an Volcanic Explosivity Index of 8, the highest recorded in the world, and the big explosion of about CE180 is noted from Chinese and Roman records. This would have destroyed immense areas of forest.

There used to be two named desert areas of the North Island, the Central plateau desert (Rangipo Desert) and the Kaiangaroa Desert to the east. Both of these are natural disasters of fairly recent origin.