Small Growers Focussed Research

Redwoods – Simon Rapley, NZ Redwood Company

The redwood (Sequoia sempervirens) resource in New Zealand has been growing slowly but steadily over the past 15-20 years. An estimated 8,000 hectares of redwoods have been planted since 2002. However, redwood in New Zealand has never benefitted from major research investment.

The FFR era

Between 2006 and 2013, redwood was part of the Future Forests Research (FFR) programme and a number of research studies were completed:

  • prediction of heartwood durability using NIR spectroscopy
  • development of a NZ-wide site growth model and productivity map.
  • a review of silviculture
  • assessment of different tree species’ capacity to stabilise soil, including redwood
  • analysis of genetics x environment in NZ’s Kuser trials – part of a world-wide network of redwood trials. Medium to high genetic control was found for all main growth and wood property traits.

Post FFR research

A limited amount of redwood research continues, driven by redwood growers. An extension of the Kuser trial study produced results similar to the first trial. A second study using NIR spectroscopy to predict heartwood durability confirmed that NZ-grown redwood has similar heartwood properties to second-growth Californian redwood – a very encouraging result for growers.

Presentation:  14 Redwoods

Specialty Species Programme – Marco Lausberg, SWP Programme Manager, FGR Ltd

The Specialty Wood Products Research Partnership (SWP) is well into its seven year term. The programme focuses on four species/species groups:

  • Douglas fir
  • Durable eucalypts
  • Non-durable eucalypts
  • Cypresses

Recent and on-going research and outputs include:

  1. Douglas fir: cross-laminated timber (CLT) testing has shown that Douglas-fir CLT has good strength properties; also that connections demonstrated high strength, stiffness and ductility. These are encouraging results for growers keen to increase the range of higher-value markets for short-length and lower quality D-fir logs.
  2. Durable eucalypts: the NZ Dryland Forests Initiative continues to make advances on a number of fronts including:
  • development of a heartwood screening tool
  • use of near-infra-red techniques to select for durability
  • forest health research has identified significant family differences in tolerance to insect pests
  • site-specific yield and survival models have been developed for two species: bosistoana and E.globoidea.
  1. Non-durable eucalypts: research continues on E.nitens drying and drying degrade; also testing thermal modification techniques to produce stable timber suitable for indoor use.
  2. Cypresses: a survey of cypress growers has identified critical siting factors; future work is planned as follows:
  • Canker-resistant C.macrocarpa planting stock will be produced and tested on a range of sites
  • wood properties (heartwood percentage and density) will be assessed in 2019
  • a sawing study is planned to determine grade recoveries from unpruned 20-year-old cypress
  • the accuracy and scope of the Cypress Calculator is to be improved.

Presentation: 15 Specialty Species Programme

Small Grower Inventory – Jonathan Dash, Scion

  1. UAVs for forest inventory

Owners of small forests are faced with disproportionately high costs to collect accurate inventory data.  Scion researchers have investigated ways to use UAVs, combined with statistical modelling, to reduce the costs of small-scale forest inventory while maintaining accuracy.

Using a representative woodlot in the Bay of Plenty, researchers have compared ways of combining different types of remote sensing data (both UAV and aerial laser-scanning) with plot-based inventory.

Research outcomes included the development of a new statistical model that allows UAV data to be incorporated into woodlot inventory. As a result, plot numbers could be reduced significantly (or precision can be increased), enabling small woodlot owners to save costs and/or have better knowledge of the volume and value of their woodlot.

  1. A community approach to data sharing

A second initiative has investigated the potential of community data sharing to develop forest yield models for any given area. In a pilot scheme, open-access data on forest boundaries in a pilot district (Kapiti, Wellington) has been combined with available plot data from forests in that district, and localised yield models developed. The models have been validated and results are promising.

Overall researchers believe that the community data-sharing approach has promise, in theory meaning that yield models for small forests could be made available to owners without the need for expensive, full-scale ground-based inventory.

Presentation:  16 Small Grower Inventory

Harvesting Hydraulic Quick Coupler – Keith Raymond, Programme Manager, FGR Ltd

The Forest Growers Research Steepland Harvesting project aims to:

  • improve productivity and safety of harvesting on steep land
  • develop new forestry equipment for domestic and export sales .

The automatic quick de-coupler has been developed as part of the project. The de-coupler enables multi-function processing and loading by one base machine, by enabling rapid switching between a grapple processor head and a log loading grapple without the operator leaving the cab. The system is ideal for smaller-scale operations (less than 220 tonnes/day), because it reduces the need for one base machine and operator.

Benefits are as follows:

  • rapid changeover improves productivity
  • increased machine utilisation and lower cost operation
  • safer operation with less machinery on the landing and no manual work to change attachments
  • new forestry equipment developed for domestic and export sales.

A prototype has been built and tested, and a NZ engineering firm will now build and commercialise the de-coupler, with at least one contractor ready to adopt the technology.

Presentation: 17 Small Growers Research Quick Coupler