Swathes of native forest are in collapse, conservation groups say, with neglect and a lack of pest control to blame for the crisis.
Swathes of native forest are in collapse, conservation groups say, with neglect and a lack of pest control to blame for the crisis.
Forest and Bird said drone footage released today showed dead and dying native trees across Northland.
The group said more than 1000 square kilometres of forest was dying, and emergency funding was needed to restore the ecosystem.
The group said native birds, bats, bugs and lizards were also at risk, under "relentless attack" from possums, rats, stoats, ferrets, weasels and feral cats.
Local conservation groups said possums eating tree leaves were running rampant in areas around Russell, Otangaroa and Whangaroa.
"Only sustained neglect over a long time leaves native forests in this state", said Forest and Bird Northland conservation advocate Dean Baigent-Mercer.
Local conservation groups said possums eating tree leaves were running rampant in areas around Russell, Otangaroa and Whangaroa.
Mr Baigent-Mercer said affected trees included totara, northern rata, puriri and pohutakawa.
"The collapse is caused by possums eating native trees to death...it's happening all across Northland in areas where there is little consistent pest control."
Conservation groups say a lack of pest control is to blame for the crisis.
Mr Baigent said pohutakawa and rata in the area were in danger of being consigned to memory.
Mita Harris, Northland Conservation Board chair, said the footage was appalling.
"Fifteen years ago I was involved in pest control in Whangaroa to keep this area alive. It's really shocking to see the bush collapse in just ten years", he said.
"Our challenge is to look at these issues again with new eyes. This means understanding the crisis that our native forests are in and looking at the pros and cons of all the tools."
He said as the area's native forests had "fallen apart", the technologies for killing pests had actually improved a lot.
Forest and Bird said an "emergency funding package" was needed to revive 105,000 hectares (1050 square km) of Northland's native forests over the next ten years.
Mr Baigent-Mercer said there was "a small window of opportunity to save many of these trees and bring the forests back to life.
"The great northern native forests are internationally significant and giving them the lifelines they deserve is long overdue. Native forests want to live."
He said the Government, hapu, and the community would all have to help restore the forests.
Footage from Whangaroa Forest showed what Forest and Bird called substantial stretches of dying trees.
The group said without intervention, the destruction would spread further.
"It has happened slowly while we sleep, night after night, year after year, so most of the time it goes unnoticed," Mr Baigent-Mercer said.
Landcare Research forest ecologist Dr Peter Bellingham said while there was good evidence to suggest that slashing possum numbers meant likelihood of tree death was reduced, pests weren't the only driver.
"It all needs to be set against a backdrop of a variety of things that can cause trees to decline," he said.
"They will die as a result of drought, and trees in Northland are also sometimes side-swiped by cyclones and these can spike death rates of trees."
Drone footage of dead trees offered a "snapshot" that didn't necessarily prove possums were to blame.
"A point in time evaluation showing dead trees raises the prospect that maybe there's a significant problem - but it's no substitute for an unbiased, temporal evaluation."
