Slash on a road in USA. Photo: Washington State Dept of Transportation

Forestry slash to be reviewed after repeated flood destruction – Expert Reaction

Cyclone Gabrielle washed out woody debris on the east coast, which has piled up against bridges and across roads.

The Forestry Owners Association today said it would welcome a inquiry into forestry and land use generally in the region, and the Minister of Forestry reportedly has some work underway.

Earlier this month there was a collective decision to hold a major independent land use review in Tairāwhiti.

The SMC asked experts to comment.

Belinda Storey, Managing Director at Climate Sigma, and Manager of the Whakahura: Extreme Events and the Emergence of Climate Change Programme, comments:

“We need to ask some difficult questions about whether harvesting forestry is a reasonable activity in Tairāwhiti. The region has some of the most erodible soils in the world, it’s exposed to extreme events, and is in the direct firing line of climate changes to these extreme events. The long term response in these locations is likely to be permanent native forestry. I recognise that forestry is a significant employer in the region. So if we move to permanent native forests, we need to think about what a just transition for those communities would be.

“We are undertaking a piece of modelling looking at how much more extreme historical weather events have been due to land use change on the east coast. We’re running the model twice: once to see what it looked like with existing land use, and once to see how much less damaging events might have been if the land was still covered in native forestry.

“Not only is Tairāwhiti exposed to the weather, but we’ve made things worse by clearing the land, first for farmland, and second replacing the farmland with harvested forestry. Trees generally are able to hold precipitation and trap it. If you have a hillside covered in trees, it tends to flood less further down. If you cut down those trees and get an extreme event – debris from that harvesting gets mobile, and that water is not held in the hillside, it moves much faster because the hillside is bare.

“At the moment private business is financially rewarded to grow a tree quickly, sequester carbon in the short-term, and then cut it down to harvest it. So all the incentives are to plant pine trees. But if we accounted for all of the costs of a disaster, I suggest native forest blocks would start to pay off. When we think about disasters we tend to think about insured losses. For example we’re probably going to get up to a billion dollars of insured losses from the Auckland flooding event a few weeks ago. But that’s just one part of it, there are all the other costs that aren’t insured. And then there are all the social costs – the cost of a kid not being able to go to school because a bridge is washed out, and the lifetime consequences for that kid if there is a significant interruption to their education. That is a cost to that individual and a loss to society, but at the moment we just don’t count it.”

Conflict of interest statement: “I am a director on Pāmu/Landcorp Farming Ltd. which owns pastoral farms throughout the country including the East Coast. Some of these farms have forestry operations.”  

Dr Nathanael Melia, Director & Principal Scientist, Climate Prescience Limited; and Senior research fellow, New Zealand Climate Change Research Institute, Victoria University of Wellington, comments:

“All was calm when the catchments contained only standing forest in the decades following Cyclone Bola, then came the clear-fell harvest. The situation with the forestry slash in Tairāwhiti has proven to be a lethal environmental disaster that has plagued iwi, hapū, and local communities for years. Although many-faceted, the cause of the problem is ultimately simple: clear-fell harvesting, where an entire stand of trees is cut down at once. I have said for years that clear-fell harvesting is an inappropriate land-use practice for the slopes and soils of Tairāwhiti.

“It is clear that the conventional voices have not provided solutions to this ongoing situation and are intent on repeating a compromised approach to appease the region’s forest owners (often international) and government ministries. It is time for this inquiry and for the voices of the local communities and forest owners led by Ngāti Porou and the hapū of Tolaga Bay to be invited to lead that conversation. It is time for the government to provide the money required for this landscape restoration and any other costs associated with changes to the local economy and employment.

“The Pine species used in these areas are fast growing and excellent at growing deep roots that stabilise the landscape. Clear fell harvestry and leaving slash on the landscape to replenish nutrients may be a valid land-use practice for the central north island where soils and slopes are relatively stable; however, this approach should never have been applied to the East Coast.

“My preference to clear fell harvesting of this landscape is that the pine species should only be selectively harvested to allow the native understory to be nurtured to maturity. This would need the backing of local and national governments and could provide ample transitional employment opportunities beyond just the current short harvesting cycle in the region. The long-term goal should be to transition the environment back to the old-growth native forests while allowing the region to flourish with investment into diverse and harmonious ecosystem opportunities.”

Conflict of interest statement: “Climate Prescience Limited conducts climate change risk assessments for large forestry companies. Nathanael has previously worked for Scion and currently working on the Whakahura: Extreme Events and the Emergence of Climate Change Programme funded by MBIE.”

Dr Tim Payn, Principal Scientist, Scion, comments:

“The challenges facing communities affected by Cyclone Hale and Cyclone Gabrielle in recent weeks have rekindled important discussions about forestry practices and the impact that forestry slash and storm debris is having in regions hardest hit by adverse weather events.

“Scion is working to support the forestry sector to better prepare for and manage the risks that come with operating planted forests under a changing climate and future uncertainty – these issues combine to challenge managers and forest owners to adapt their forest management practices.

“Co-developed with industry, our Resilient Forests Research Programme started in 2019 and is designed to ensure the long-term economic, environmental and social sustainability of forestry by creating forests that are more resilient to the impacts of climate change, pests and disease and an industry which is resilient in the face of socio-economic shocks, for example global pandemics or regional unrest. This work builds on previous environmentally focused research programmes.

“With industry, we are carrying out research trials to identify forest management practices that aim to future-proof the productivity of forests whilst recognising the need to apply bespoke systems in regions that are most likely to require highly site-specific solutions to meet the needs of both regional communities and the forest industry.

“Three-and-a-half years into the programme, research is highlighting where system changes could be applied. This includes optimisation to increase productivity of plantations where it is sustainable – an approach that will support the industry to diversify or move away from forestry in more climate-affected regions. Through surveys of industry stakeholders, we are also building a better understanding of the factors that motivate forest growers to adapt and make changes to forestry practices.

“Changed land use and management systems that address the impact of erosion, slash and storm debris on communities are a long-term challenge; an all-of-systems approach must be considered as part of the solution. This could include retreating forestry from risky sites whilst supporting the forestry sector to remain productive and generate new high value from slash and woody debris – solutions that will also support regional growth through the development of new manufacturing sectors and exports. Scion’s research, innovation and technology has a lot to contribute to these new ways of thinking in the face of more frequent high intensity rain events.

“Climate change is driving an increasingly urgent need for adaptation across forestry in regional New Zealand. Our research, which is aligned with our Strategy to 2030: Right tree, right place, right purpose, is helping to inform industry decision-makers and government agencies about options they have in an uncertain future.”

Conflict of interest statement: “Scion works closely with forestry industry, Te Uru Rākau and MPI. I am a member of the Forest Owners Association environment committee.”

Professor Euan Mason, New Zealand School of Forestry, University of Canterbury, comments:

“An inquiry into land use on the East Coast, including into forest harvesting operations, slash movement, and erosion is warranted. Climate researchers report that cyclones are likely to increase in frequency and ferocity as the world warms, and so we must re-examine our behaviour and respond appropriately, particularly on such fragile sites.”

No conflict of interest declared.

Campbell Harvey, Lecturer, New Zealand School of Forestry, University of Canterbury, comments:

“An enquiry into East Coast land use could drive sustained change for the environment, community and the local economy, across multiple sectors. Forestry practices made major shifts in recent years to improve worker safety while also meeting the challenge of increasing harvest volumes. Investment in the solutions needed for these more frequent storm events requires that same drive, and the review could clarify the directions for all sectors using vulnerable lands.”

No conflict of interest declared.