Te Hoiere Restoration: Forestry Riparian Trials in OneFortyOne New Zealand’s Tinline block

The Te Hoiere Restoration Project is underway in OneFortyOne New Zealand’s Tinline Block.

This is a project to research and understand the Te Hoiere (Pelorus) catchment and the land uses within – current activities, impacts and opportunities for improvement.

Funding from the Ministry for the Environment has been allocated in early 2024 to enable a series of research projects – with five forestry-based projects underway through the Top of the South Wood Council (TOTSWC).

One such project is looking at reinstatement and enhancement of riparian margins within exotic forests – using a variety of re-establishment techniques to assess viability physically and financially and which can be replicated in remote and difficult access terrain.

OneFortyOne’s Tinline block now has three trial zones in two different geo-locations. Each of the trial zones has 5 x 100m x 10m individual trial areas established, which will give the replicants of each trial.

Trials initiated are:

1. Do nothing.
   • No spray, allow natural regeneration post-harvest, no control of regen or ‘undesirable’ weeds (eg : old man’s beard).
2. Do nothing, manual plant.
   • No spray, manual planting of natives. ‘Timata’ planting method of approx. 2,500 stems/ha equivalent at 2x2m spacing. 50% manuka/kanuka, balance mixed natives (heavy in pioneer species).
3. Target spray weeds, allow natural regeneration post-harvest.
   • Spray competitive and undesirable weeds (old man’s beard, banana passionfruit, Himalayan honeysuckle & other weeds which are fast growing and risk swallowing native regen).
4. Manual spot spray, manual plant.
   • Pre-plant spot spray 1.2-1.5m diameter spots at 2x2m spacing. Manual plant into spots using 50% manuka/kanuka, balance mixed natives (heavy in pioneer species).
5. Aerial spot spray and seed by drone.
   • Pre-plant spot spray 1.2-1.5m diameter spots at 2x2m spacing. Aerial broadcast application of native seed infused ‘bombs’ from drone.

Trials within trials :

Each manual planting trial has 2 x rows of mixed Manuka and Kanuka as species ‘upalatable’ to ungulates and a further 2 x rows of mixed species common to the Tinline area (10 species, 5 plugs of each species in each row. This is to look at species palatability and susceptibility to grazing in an open environment.

Drone spraying is regular spaced chemical spots (where no existing native vegetation is present). Drone seed application is broadcast across the whole trial area. This is to look at native establishment with and without chemical assistance.

Each of the 15 trial areas has 2 x PSPs established within the boundaries. A 5mx5m ‘open’ plot and a 5m x 5m deer fenced ‘exclusion’ plot. This is to look at the effect of uncontrolled browsing vs full exclusion across the range of trials. Ecological assessments and measurements are being undertaken 3 monthly until trial completion.