In 2022, and then again in 2024, the Northland Tōtara Working Group (NTWG) harvested small volumes of tōtara from the same Pāmu (Landcorp Farming) property in Northland. Both harvests involved single-tree selections and low-impact felling and extraction techniques, (in accordance with the Sustainable Forest Management Plan approved under the Forests Act). Both harvests demonstrated that small-scale, low-impact, selective harvesting can be viable, but a good crew and matching the right-sized machinery to the job is important.
Different harvests different machinery
The 2022 harvest generally targeted smaller trees and focussed on production-thinning amongst dense stands of pole-sized trees. There, portable sawmiller, Li Legler, used a small 45-hp four-wheel-drive tractor with a PTO-mounted forestry winch to great effect. In comparison, the 2024 harvest targeted some much bigger trees (see table below). Bigger machinery would be needed. But would that still be economic for a small-volume harvest?
Sustainable harvests – little and often
The regenerating tōtara forest areas of the property total 27.7ha and the approved SFM Plan allows for a total annual harvest of only 8.6m3. This equates to a harvest rate of only 0.3m3/ha/yr. For practical reasons, several years’ worth of allowable harvest volume may be applied for in each logging plan. However, the actual harvest volumes are still small. Selection harvesting in this forest requires frequent but small-scale harvest operations. This has implications for harvest economics.
Harvest tree selection and forest management
In both operations, harvest was largely used as a production-thinning intervention – or silviculture, to try to improve the stand in the long term. This means a single-stem selection process, with the focus on removing poorer (but still merchantable) trees from the forest to the benefit of adjacent and better trees which are left to grow on – to become even more valuable.
Manawhenua determined the harvest date according to maramataka and graced the occasion with karakia.
Big trees
The 2024 harvest involved some much larger trees. One tree was dead, but still standing, and with 100cm diameter at breast height (DBH) and a 12m bole. Other live trees included several with DBHs between 75 and 95cm, and approximate log volumes between 4.2 and 6.5m3. These were located on steep terrain beneath the adjacent paddocks. Such logs were far too large for Li’s small tractor and winch. Therefore, Tom Harrisons Future Limited was engaged and used a 12-tonne DH4 tracked skidder with a powerful winch.
Low impact extraction
Avoiding damage to the residual forest during felling and extraction was another key criterion of tree selection. Harvested trees were generally within 50m of the forest edge and where a machine could get close enough on the adjacent paddocks. The machinery did not enter the forest. The fence was cut in several places to pull the logs through but the skidder stayed on the paddocks. It used the winch rope to assist with directional felling and extract the logs. Top logs were not separated from the butt logs, and despite the steep terrain, the powerful equipment managed to pull the...
