This week saw the release of the IPCC report pointing to significant trends in climatic effects on New Zealand farming and forestry. One trend was that climate change is expected to increase the number of days with very high and extreme fire weather. This has equally severe implications for forestry as we know it in New Zealand.
The principal plantation forestry tree in New Zealand is pinus radiata, a pyrophyte or fire tree that ecologically expects to undergo burning every so often to allow genetic diversity to flourish by regrowth of fresh trees from a mixture of crossed pine seed. The tinder of pine needles that builds under pine trees, instead of faster decomposition as occurs in most indigenous or deciduous exotic forest systems, is part of that process.
That the eastern and northern parts of New Zealand are expected to become drier and more at risk of significant fires should be a consideration for future forestry plantings. Planting permanent canopy systems of selected mixed indigenous and deciduous exotic tree species could heavily reduce risk of wasteful and dangerous forest fires, improve carbon sequestration and other environmental processes, and be part of a transition towards a higher value timber products industry.
Currently pinus radiata’s dominance limits best value options and perpetuates environmentally damaging forestry management. The Ministry of Primary Industries has a report that shows damage to coastal fisheries from sedimentation including from forestry land disturbance. The forestry industry suggests that even current strong prices for export logs are not enough to move to less damaging harvest methods that would reduce sediment runoff. Better forestry methods with higher returns could happen with government support of a new vision for the sector that includes different and a more fire resistant species mix. I will report soon on the lagging National Environment Standard – Plantation Forestry that cabinet has stalled on because of cost – benefit ratios that industry doesn’t like but mean more fisheries habitats are impacted.