SITE CHARACTERISATION, TREE GROWTH MEASUREMENT & MODELLING

Understanding the specific site requirements of different eucalypt species, and combining this information with accurate measurement of different species' productivity on different site types are essential parts of NZDFI's research programme. Researchers at the University of Canterbury School of Forestry have developed a growth, heartwood volume and carbon models for E. globoidea, one of our two key species.

Matching elite high-value eucalypts to productive drylands

Research into site/species matching began with an AgMardt-funded project, ‘Matching elite high-value eucalypts to drylands’.

The project's aim was to:  'Establish hybrid physiological/mensurational yield models for durable dryland eucalypt species and to connect microsite variation with larger scale variation in site influences on tree species'.

Research included the first tree growth modelling work, undertaken by PhD student Serajis Selakin. Serajis developed the first E. globoidea growth model, which has since been  further developed by other researchers.

More details of the AgMardt project 

Tree Growth Measurement and Modelling

Modelling E. globoidea stem taper and heartwood

An E. globoidea stem taper and heartwood model was developed by PhD student, Daniel Boczniewicz. Daniel developed an interactive tool where users can input tree diameter at breast height and tree height data to predict the height, volume and taper of heartwood, wood inside bark and wood including bark. The tool also provides visualisations of all of these components.

Daniel's 2023 PhD thesis is freely available:

• Developing fully compatible taper and volume equations for all stem  components of Eucalyptus globoidea trees in New Zealand

Measuring and modelling E. bosistoana and E. globoidea growth and carbon sequestration: a regional approach

In 2022-24. a Marlborough regional forestry and biomass project included a significant amount of work on work on a regional E. globoidea growth model. Carbon sequestration was included for the first time. The MPI Sustainable Land Management and Climate Change (SLMACC) project has been led by Prof. Euan Mason.

Some intensive fieldwork was required. A summer student crew felled selected trees at NZDFI trial sites across Marlborough. Solid wood components of each tree were weighed and measured, and then all components, including branches and foliage, were transported to the School of Forestry for drying and further measurement.

More details of the fieldwork were reported in our Project Update July-December 2022.

Following lab analysis of all the dry matter components of the sample trees, a Marlborough regional growth model for E. globoidea has been developed, with progress also made on modelling regional E. bosistoana growth. A carbon sequestration component has been added to the generic E. globoidea  growth model.

An example from the on-line E. globoidea growth model including carbon function (click to enlarge).

Using UAV-LiDAR to measure individual trees

As part of the Marlborough Regional Sustainable Land Management and Climate Change (SLMACC) project, researchers investigated the potential for using UAV-mounted LiDAR and machine learning to estimate individual tree biomass.

More details of the UAV-LiDAR research

Conventional approaches to durable eucalypt measurement

The NZDFI breeding programme relies on a network of over 700 permanent sample plots (PSPs). These PSPs are measured regularly, and data is stored in our Katmandoo meta-database. The data is beginning to reveal valuable information about site/species adaptability and productivity, and can guide more detailed modelling work.

More details about our PSP network

Results from trial measurements