The tsunami of forestry slash last month will likely happen again on the East Coast unless the industry stops clear felling erosion-prone area, says forester Chris Perley.
It's been one month since a deluge in the hills above Tolaga Bay sent thousands of unwanted logs careering downhill - clogging up rivers, endangering lives and destroying homes.
Perley said similar events had occurred in Hawke's Bay, such as in the Mohaka catchment eight years ago.
"There will be more of those weather bombs coming through," he said. "With climate change, they will be more frequent and they will be more intense."
Gisborne mayor Meng Foon said the pine forests were planted as an alternative to pasture, which failed to hold onto the previously bush-clad land.
"Back in the 60s and 70s there was a lot of planting done by the Crown, and it was a matter of ensuring the East Coast region's land didn't actually erode down into the sea," he said.
"If you have a look at past pictures of now and then, in terms of erosion in those days and what has happened now, it has been a remarkable change."
Perley said pinus radiata was a low-value wood so it was sustainable only when costs were controlled by measures such as clear-felling, leaving the erosion-prone land vulnerable.
"We need to challenge the paradigm of clear-felling radiata pine on steep country, where there are weather bombs and where there are erodable soils. Just get out of it. Just rethink."
Currently radiata is harvested at the age of 26 to 28 years, confirming its status as low-value timber at a less stable age.
"From a forestry perspective that's a sprint," Perley said.
"Totara we can do in 80 years. Totara is an incredibly brilliant species but we've still got this young, grow-it-quick, grow-the-same, grow-it-cheap attitude."
Manuka was being planted for honey production on some steep hills with erodable soil but he said higher value native trees may also provide higher margins as well as enable the forest canopy to remain through selective logging or smaller-scale harvesting.
Such native trees would also enable local processing of timber with more jobs and an intergenerational forest model, as found overseas.