Forestry slash unfairly in firing line: Dodson

Woody debris, including slash, caused damage to infrastructure following the Cyclone Gabrielle...
Woody debris, including slash, caused damage to infrastructure following the Cyclone Gabrielle deluge in the North Island. PHOTO: BRIDGET PARKER
Slash. It’s a word that has become familiar following the cyclone devastation in Hawke’s Bay and the East Coast.

New Zealand Forest Owners Association president Grant Dodson, who is also chief executive of Dunedin company City Forests, says forestry slash has been in the "firing line" since the destruction in the North Island.

He believed there had been a media witch-hunt against it and forestry companies, organisations pointing the finger at slash but the reality was phone lines were down, roads failed and farming "washed into the sea". Everything "got trashed".

"So the issue now on the East Coast is how do we do better? Because the answer is not clear and straight forward. The reality is, if you look at solutions, particularly for the Gisborne area, trees are definitely part of the solution," he said.

The setting was literally a perfect storm; very weak soil geology overlaid with the area of New Zealand which collected most of the cyclones in a time of Climate Change.

"That place is going to get hammered in the future and it can’t handle it. We’ve got to be smart about building resilience," he said.

Mr Dodson acknowledged the forestry industry needed to do more to reduce the impacts of slash, but farming practices also needed to be looked at and there had also been some real issues around the resilience of public infrastructure. Everyone needed to be part of the conversation. "All everybody wants is a fair hearing, eh," he said.

The East Coast area was cleared in the 1800s and early 1900s for sheep and beef farms. Photographs from floods decades ago showed the beach at Gisborne covered in trees. Yet that was before pine trees were planted, Mr Dodson said.

The land form was weak and it was prone to erosion. Cyclones Bola and Bernie, in the 1980s, "just ripped that area to pieces" — as had happened again — and, after an inquiry was held, there was a move to plant pine trees.

What was probably a mistake, was picking up the commercial radiata pine forest model and "plonking it" on highly erodible soils. It did its job for the first 30years and "pretty much held that land together".

Then the forestry industry started harvesting on those extremely erodible soils and on extremely steep slopes. It was dangerous work and there were fatalities.

Once the canopy was removed, rain drops would get to the soil, causing erosion, roots would start withering and the soil structure was not held together.

The forestry industry had done a lot better in terms of moving slash away and building better roads. But the twin cyclones this year clearly showed that although it had done better, it had not done enough, he said.

A weather station next to forestry in the Esk Valley — one of the hardest hit areas — measured 770mm of rain in 24hours, many other stations recorded 500mm to 600mm. No land use would really survive that impact.

"How can you be resilient with 600mm in 24 hours on highly erodible soils?" he questioned.

New Zealand Forest Owners Association president Grant Dodson. PHOTO: SALLY RAE
New Zealand Forest Owners Association president Grant Dodson. PHOTO: SALLY RAE
Slash is defined in the National Environmental Standards for Plantation Forestry as "tree waste left behind after plantation forestry activities". When it came to what was littering Hawke’s Bay and Gisborne, Mr Dodson believed woody debris was a better phrase.

Slash was a component of it but it included everything from fence posts and fruit trees to willow trees. And it was that woody debris which had taken out bridges and knocked over buildings.

From what he had seen, Mr Dodson said it appeared the majority of woody debris on the beach was willows, fence posts and orchard residue. Moving further north, there was more forestry slash.

Sediment was much harder to deal with than slash and it had a hugely significant impact, particularly in Hawke’s Bay. While farmers, who had land destroyed, would get subsidies for regrassing, there was "clearly an inconsistency".

Science needed to be looked at and catchment-by-catchment solutions developed that involved land use and rules around land use, combined with suitable public infrastructure. "There’s a real need to put a lot of scientific research into that, what we need to do," he said.

What really worried Mr Dodson about the East Coast was its potential abject poverty in 10 years time. Forestry in the area was well known in the industry "to be a money churner, not a money maker".

About 25 or 26 harvesting crews left the East Coast, for purely economic reasons, in the last quarter of last year, each comprising six to 12 people. Statistics showed one in four families on the East Coast derived income from forestry.

One of the other issues was there was no economic market there for forest residue — there was a small amount of wood processing in the Gisborne area — but there was "nowhere to take it to, no-one wants it".

The forestry industry had put in place some limited amounts of woodchipping to try to move residue off-site, with a negative margin.

There was now going to be more cost loaded on to existing businesses, including building expensive slash traps.

"My concern, if we don’t really nut this out, is industry by industry, that place is going to be an economic backwater."

sally.rae@odt.co.nz