Images provided by Biosecurity New Zealand show the threat wilding pines present to New Zealand landscapes.
The images show the unchecked spread of pines at Mid Dome, Upper Tomogalak catchment, in Southland from 1998 to 2015.
On Thursday, Biosecurity Minister Damien O'Connor told the New Zealand Wilding Conifer Group annual conference at Omarama the National Wilding Conifer Control Programme would now target 150,000ha in Canterbury, Otago, Southland, Marlborough and the Central North Island.
The programme had treated 500,000ha of land and searched a further 1,000,000ha for outliers, with 40,000ha of dense and moderate infestation removed.
Before control efforts, pines were spreading about 90,000ha each year, and with control under way still cover about 5% of the landscape.
Estimates suggest that if left to spread on their own, the invasive pest plant would cover 20% of New Zealand's total land area — 5,400,000ha — by 2030, Ministry for Primary Industries wilding conifer control programme manager Sherman Smith said.
In a statement, Mr O'Connor said to date the Government has spent $12.4 million on wilding conifer control, with $5.8 million from other parties.By 2030, the programme aimed to have contained or eradicated all wilding pines.
The conference continues today with a field trip stopping at Peters Lookout, Irishman Creek Station and Mt Cook Station, which would focus on the work already done and the challenges remaining.