Keeping woody debris inside our forests – what we need to do

Publication: New Zealand Journal of Forestry, Volume N.Z.J.For. 2023, Issue N.Z.J.For. 68(1) 2023, pp 3-9, May 2023
Publisher: New Zealand Institute of Forestry

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Abstract: Recent storm events have again highlighted the damage to infrastructure and communities from extraordinary rainfall, associated flood waters, woody debris and sediment derived from a range of land uses, including production forests, especially on the East Coast of the North Island. Public outcry has led to the establishment of a Ministerial Inquiry, which will include issues of woody debris. With the expectation of an increasing frequency and severity of storm events from climate change, major changes need to be made to reduce the impacts of forestry outside boundaries, ideally moving to a state where no material leaves the forest. There are many possible approaches identified (such as extraction of the woody residues left on-site for bioenergy or other bioproducts), changes to harvesting practices and on-site management of residues, and the installation of technologies (such as slash traps or riparian buffers to keep materials out of waterways). New silvicultural approaches (such as small coupe harvest, production thinning, continuous cover, or conversion to permanent native forest) are emerging areas that need urgent exploration. Achieving zero woody debris ‘escaping’ from the forest boundaries is not realistic, but reductions are possible and will require a multi-pronged approach. However, there are large gaps in research understanding, especially in the areas of new forest management regimes. New, large-scale, on-theground long-term experimentation is needed, with scientists working very closely with foresters and contractors, regulatory bodies and communities. The environmental, social and economic aspects of any new approaches also need to be considered together.

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