Case study: Erosion control plan grows future income

A 559-hectare drystock farm in Haruru is working with Northland Regional Council to control erosion and improve water quality in a project that will generate forestry income for the farm in the future.

Owner and farm operator Mack Lynn identified four steep areas of Lynn Brothers Farm that were vulnerable to slips and gullying, and developed a plan to reduce erosion and sedimentation while securing income for the farm’s future.

Totalling 20.3 hectares, the four areas were all highly erodible land where slips and landslides were resulting in high sediment yields into waterways running into the Waitangi River.

Supported by a $56,840 two-year grant from Northland Regional Council between 2020 and 2022, Mack planted 12,000 manuka over 6 hectares, 5,400 tallowwoods (eucalyptus) over 2.7 hectares, and a mix of 11,600 redwoods and Italian alders over 11.6 hectares.

To prepare for planting, Mack installed three-wire electric fencing around the areas to keep stock out and controlled weeds and browsing pest species.

The alders and redwoods were interplanted, with the alders helping the redwoods to establish by fixing nitrogen and acting as a ‘nurse’ crop. The redwoods will eventually overtake the alders, providing permanent forest cover to mitigate erosion on the steeper slopes and yielding high-value timber.

The innovative, low-input forestry regime had been tested successfully in New Zealand but not previously used in Northland. This flagship planting demonstrates innovation, good practice and appropriate species selection for the site.

Redwood and tallowwood are particularly suitable for a permanent forest cover for erosion control and single tree harvesting. When trees are harvested, the roots stay alive and stumps regenerate into new trees. Both species are shade tolerant and both produce high-value timbers.

The manuka were planted in permanent retirement areas to succeed into native forest cover.

Two years in, 87% of the trees have established well, with the remainder damaged by possums.

To find out more about grants available from Northland Regional Council for landowners, visit the Funding and Awards for Landowners page on our website or contact a Land Management Advisor on 0800 002 004.

Manuka growing well on Lynn Brothers Farm.

Manuka growing well on Lynn Brothers Farm.