Fire crews last night feared the large fire brought under control yesterday in the Berwick Forest pine tree plantation would flare up again.
Six hectares of 14-year-old pine trees in an area of the 13,141ha forest had been destroyed by yesterday afternoon.
The Fire Communications Centre was alerted to the fire about 1am yesterday and volunteer rural fire crews from Waihola, Outram and Milton, private crews from Wenita and City Forest and rural firefighters from Dunedin City and Clutha District councils responded.
Fire investigators were at the site yesterday.
It was not known last night how the fire started.
The trees destroyed yesterday were planted in 1995 to replace those burnt when a fire razed more than 300ha of pine plantation, Wenita chief executive Rodger Hancock said.
The forest is owned by Ngai Tahu and managed by Wenita.
Mr Hancock estimated about 2000 trees would have been destroyed by yesterday's fire and most were about halfway through their growing life.
Mr Hancock said it was too dangerous for crews to enter the forest on Sunday night.
"Freakish" conditions - such as a temperature of 23degC at 2.30am, strong winds and very low humidity - meant the fire burnt ferociously.
At daylight, four helicopters with monsoon buckets worked to bring the fire under control, with ground crews entering the forest about noon.
The fire had threatened power lines.
Ground crews were working yesterday afternoon to "open up" and dampen down hotspots.
Mr Hancock said crews would be at the site for "at least" a couple of days.
A Fire Services spokesman said firefighters were continuing to dampen hotspots last night.
