Project Update January - June 2023 - NZ Dryland Forests Innovation

Twelve Australian eucalypt growers and processors, all of whom are involved in growing and/or processing plantation durable eucalypts in south-eastern Australia, visited Canterbury and Marlborough in March 2023. The group, known as the Durable Eucalypt Growers Forum, were hosted by the Specialty Wood Products Research Partnership (SWP) and NZDFI and came to look at a range of NZDFI durable eucalypt seed orchards and trial sites over three days.

The visit began at the University of Canterbury School of Forestry, and the group then travelled north, calling in at Proseed NZ in Amberley and then a number of trial sites en route to Blenheim. The Australians were particularly interested in how NZDFI has targeted and improved certain wood properties.

“The Australians have a lot more experience on the operational side of plantations of durable eucalypts,” says Marco Lausberg, SWP Programme Manager, “as they have been planting them for a lot longer than in NZ, and understand which species do well where in Australia.”

The final day included a forum at the Marlborough Research Centre (MRC). Marco says “the forum was about hearing from the visitors. Setting up processing facilities, dealing with waste as well as harvest options – where smaller machinery was needed than for radiata - were on the agenda.”

Grower Chris Swadling from New South Wales was amongst the visitors. Chris owns ‘Ironwood Australia’, a leading supplier of reclaimed, recycled and architectural Australian hardwood timbers. Chris admired the stunning suffits (made of Eucalyptus pilularis) of the New Zealand Wine Centre, clad with the timber cut and supplied by him.

There are a range of viable emerging uses for eucalypts including construction and furniture and even export to Australia, where consumers want these hardwoods but where they are now in short supply. New Zealand’s challenge is to scale up planting to establish a supply chain that can begin to make in-roads into export markets.

Kaara Shaw, a forester from South Queensland, was impressed with what she saw:

“For several years now, we have been hearing about the extensive durable eucalypt breeding work that is being undertaken by NZDFI across New Zealand. To see the trials and laboratory work first hand, and to hear from those passionate people who are leading the charge on the ground, was both humbling and inspiring. The work that NZDFI are doing will be the foundation of a successful durable hardwood plantation industry in New Zealand. We can only wish for the same level of foresight and support from the Australian Government, for our own plantation development activities across The Ditch.”

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A technical report summarising the performance of different species across NZDFI’s trial network (2010-2018 plantings) has been produced by Paul Millen, Ruth McConnochie and Euan Mason, and is available on the Forest Growers Research website (SWP – T164):

Variation in adaptability and productivity between durable eucalypts species in different New Zealand environments

This is the final NZDFI report produced under the seven-year Specialty Wood Products Research Partnership (SWP) that ended on 30 July. The report draws on permanent sample plot (PSP) data collected at regular intervals across 33 trial sites to provide a comprehensive analysis of species’ survival and growth on the different site types.

Analysis focused on 14 older NZDFI demonstration trials that included up to eleven species and were planted in either 2011, 2013 or 2014 and remeasured over 2020-2022. These trials are located across a diversity of regional environments with different climates and geology.

Species in these trials were selected based on a range of criteria, informed by earlier New Zealand and Australian research and experience: Selection criteria were:

fast growth
stem form (straightness)
drought and frost tolerance
pest tolerance
early durable heartwood formation and timber colour
vigorous coppice
good nectar/pollen production for native biodiversity and bees.

Wood durability classification and heartwood colour were important factors in species selection: these factors will determine the range of potential uses for the wood produced.

The report summarises the performance of the eleven species in three groups (see Table 1 below):

Class 1-2 brown heartwood
Class 2- 3 brown heartwood
Class 1 red heartwood

Table 1: NZDFI trial species and their durability classification and heartwood colour.

Results presented include:

Survival percentages of up to eleven species for eight sites planted in 2011 and six sites planted 2013 or 2014.
Overall species ranking for average growth and variance
Species diameter at breast height x height analyses
Productivity of each species on each site in terms of height growth (mean top height mean annual increment - MTHMAI) – see an example below:

Fig: Class 2 and 3 brown heartwood species comparative growth Mean Top Height Mean Annual Increment (MTHMAI) across all sites. The Technical Report includes graphs for all three species groups.

The Discussion section reviews each species based on the data analysis plus a range of additional factors such as international experience, form and branching, and insect tolerance, and makes recommendations on site x species suitability.

Additional information includes the genetic seed sources of all seed used in the trials, a trial site database which includes climate and site information, and a comprehensive list of the technical reports produced by NZDFI as part of the Specialty Wood Products Research Partnership (SWP, 2015-2023).

Overall, the report reinforces the message that growers need to understand their environmental site conditions and select durable eucalypt species that are adaptable and productive.

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A short project funded by Industry Transformation Plan (ITP) and FGR has enabled the NZDFI team to further assess the performance of Eucalyptus machrorhyncha in NZDFI trials, with a view to genetic improvement of the species. E. machrorhyncha has demonstrated good potential in NZDFI’s trials particularly on colder drier sites that exclude other species already selected for breeding.

Ruth McConnochie led the field work to visit 19 sites to assess existing PSPs within NZDFI trials and several other small forestry blocks. Trees were assessed for growth and form with ‘plus’ trees selected and seed collected to provide individual seedlots for future deployment either in a seed stand or pedigreed tree breeding programme. .

At the same time, Dr Steve Pawson, University of Canterbury School of Forestry, prepared a report on biological risks: "Pests and Diseases of E. machrorhyncha". Steve identified that E. machrorhyncha currently shows little insect defoliation in NZDFI trials compared to other species. However, fungal leaf diseases could pose a potential future threat in areas where climate change will bring warmer, wetter conditions. This highlights E. machrorhyncha’s preference for low rainfall and low humidity regions.

Ruth’s field work also included remeasuring PSPs and assessing the form of three other NZDFI trial species - E. argophloia, E. longifolia and E. tricarpa. These are all class 1 durable species that produce red heartwood and are of interest to NZDFI because of their potential to produce high value, richly coloured products, similar to tropical hardwoods such as rosewood.

Expert participants at a recent on-line workshop agreed that E. machrorhyncha and E. tricarpa offer the most potential to extend the NZDFI breeding programme at this stage. Both E. argophloia and E. longifolia have proven too variable within the trial network to justify further investment in a breeding programme.

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Update on NZDFI PhD students

Congratulations go to two more of NZDFI’s PhD students, Daniel Boczniewicz and Leslie Mann, who have both now been awarded their PhDs.

Daniel Boczniewicz’s thesis: Developing fully compatible taper and volume equations for all stem components of Eucalyptus globoidea Blakely trees in New Zealand, is available here:

https://hdl.handle.net/10092/105183

http://dx.doi.org/10.26021/14278

Daniel contributed to the work of the NZDFI in many other ways. A skilled videographer, he was responsible for producing at least 13 NZDFI videos. He has taken up a position at the Ministry for the Environment.

Leslie Mann’s research related to insect pest browsing of durable eucalypts. As well as building on earlier research to identify browsing-tolerant species and genotypes, Leslie successfully developed a way of identifying and quantifying browsing damage on durable eucalypts using UAV-based LiDAR. Together with Dr Steve Pawson she has produced two valuable SWP Technical Reports:

Technical Report SWP 140 – Eucalyptus resistance to paropsine beetles

Technical Report SWPT153: Assessing paropsine damage on Eucalyptus trees with remote sensing

Leslie has taken up a job with the Ministry for Primary Industries Biosecurity team; her thesis will be available on-line soon.

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Two further PhD candidates, Vikash Ghildiyhal and Seol-jong Kim, are both close to completing their PhDs. This makes an impressive total of 12 School of Forestry PhDs to date, all of whom have contributed significantly to advancing our knowledge of various aspects of durable eucalypts.

Another PhD student, Carolin Weser, is part-way through her PhD looking at the ecology of defoliating beetles (see below). Two new students, Shiva Pariyar and Milad Lezgi, have recently embarked on their research at the School of Forestry.

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**Phenology and natural enemies of Parospsterna cloelia and Paropsis chayrbdis in Marlborough**

Carolin Weser finished her second field season end of March 2023 after completing a total of 15 fortnightly sampling trips to the Dillon and Lawson NZDFI trial sites.

As in the previous year, two generations were recorded for both beetle species at Dillon; at Lawson, however, only one generation was produced, as the coppices did not re-foliate after the extreme defoliation of the first generation.

The diversity and abundance of predatory arthropod species was higher at Dillon (8 insect species, 7 spider families) compared to Lawson (4 insect species, 5 spider families).

Carolin developed two species-specific qPCR assays to detect the DNA of the paropsine beetles within the bodies of field-collected predators to confirm predator-prey associations. The molecular analysis complemented abundance data and field observations. It confirmed the Schellenberg’s soldier bug as the most abundant and most active predator of paropsines. Both adults and nymphs feed on all paropsine life stages including adults. The Tasmanian ladybeetle wasn’t as abundant but was an active predator. Other less abundant species, including three spider families, are less frequent predators of paropsines. Red whirligig mites feed on eggs and newly hatched larvae.

To quantify the effect of existing egg parasitoids on both beetles, a total of 624 egg batches were collected and reared in the laboratory. Emergence data show that egg parasitoids have an impact on P. charybdis, but Pst. cloelia is little affected on favoured trees where it is abundant.

Carolin also checked eucalypt trees between Christchurch and Blenheim and discovered that Pst. cloelia has reached Cheviot but was not yet present in Waipara.

All images are © Carolin Weser. Click to enlarge to see some fantastic photography.

: Red Anystis mite feeding on Pst. cloelia eggs.

: Parasitoid wasp Neopolycystus insectifurax sitting on P. charybdis eggs.

: Parasitoid wasp Enoggera nassaui is approaching Pst. cloelia eggs.

: Older nymph of the native Schellenberg’s soldier bug feeding on adult Paropsisterna cloelia.

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Welcome to Shiva Pariyar

Shiva Pariyar is a new PhD student from Nepal. Shiva holds a Master's degree in Forest Ecosystem Science from the University of Melbourne, Australia in 2016 and a B.Sc. (Forestry) from Tribhuvan University in Nepal. Shiva has served as a Forest Officer for the Nepal Government since 2010.

Commencing his PhD in June 2023, Shiva is enthusiastic about his research focus: the assessment of forest health and vitality in New Zealand's eucalypt plantations through remote sensing techniques. He is working under the guidance of Vega Xu, Steve Pawson, Justin Morgenroth, and Ning Ye.

Shiva's research centres on using cutting-edge remote sensing technologies, including UAV, LiDAR, and satellite imagery to detect, assess, map, and monitor defoliation at the individual tree and the forest stand levels. He plans to work on developing a novel approach for collecting ground truth data, investigating variations in resistance and tolerance at various levels of defoliation, and scaling up in-situ studies conducted at the tree/plot level to encompass the broader scope of stand and landscape.

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Milad's PhD will focus on the innovative application of mixed-species Cross-Laminated Timber (CLT). Under the expert guidance of supervisors Thomas Lim, Clemens Altaner, and Gregory MacRae, Milad's research centres on unlocking the potential of Eucalyptus bosistoana and radiata pine in structural engineering. This encompasses unravelling the mechanical properties of New Zealand-grown E. bosistoana, and extends to its practical application as a CLT floor system.

Milad would like to thank the UC School of Forestry and the WIDE Trust for their support, which has turned his dream of pursuing a Ph.D. into a remarkable reality.

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Marlborough Sustainable Land Use Case Study

In the last Project Update (July-December 2022) we reported that NZDFI had been awarded funding for a Marlborough Regional Case Study from MPI’s Sustainable Land Use and Climate Change fund (SLMACC).

The project is proceeding well. Summer field work and lab work to destructively sample and measure total biomass of E. globoidea and E. bosistoana was completed by a combined team of Professor Euan Mason, Ruth McConnochie and Ash Millen working with five University of Canterbury undergraduate forestry students. Ning Ye, another UC PhD student was involved in capturing LiDAR imagery of trial sites. This work was supported by the landowners participating in this project.

The next tasks involve preparing case studies of four landowner properties business operations to analyse the potential for durable eucalypts to help offset greenhouse gas emissions and deliver other benefits such as a supply of durable eucalypt posts. Bioenergy New Zealand Executive Officer Brian Cox will lead a bioenergy investigation, including assessing Marlborough’s wine industry and other local industry energy needs and where biomass can most efficiently provide an alternative to existing energy sources.

An in-person workshop and an on-line forum are planned for later in 2024, where the outcomes of the research will be presented.

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Our commiserations go to all those who were adversely affected by Cyclone Gabrielle, and its almost forgotten, but in some places just as damaging, predecessor, Cyclone Hale.

Several NZDFI trials in Hawke’s Bay took a beating from Cyclone Gabrielle, including at Uptons 2021 seedling seed orchard, where a couple of large slips took out 30-40 trees, the Hawkes Bay Regional Council’s 2021 E. bosistoana breeding population trial in the Tukituki River floodplain which was inundated with flood water - most trees have survived and righted themselves, although some will have to be coppiced - and Pamu/Landcorp’s 2021 demonstration trial at Waitere, where there were multiple slips. There were also a small number of E. globoidea windthrown in the Pamu/Landcorp’s 2018 demonstration trials at Edenham in Central Hawkes Bay.

We were fortunate in that both our Northland and Wairarapa trials appear to have come through the challenging winter weather relatively unscathed.

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Research proposals pending

Three one-year research proposals have been submitted to FGR for consideration under the 2024 funding round. We await the outcome of the Research Committee’s deliberations.

The proposals include:

Ensuring product quality in durable Eucalyptus plantations through further coring and analysis of NZDFI’s breeding populations. If successful this project will also provide support for another new UC PhD student in their research programme.
Collection of elite E. globoidea seedlots to advance NZDFI’s breeding programme
Automated detection of Eucalyptus defoliation using remote sensing. If successful this project will also provide support for another new UC PhD student in their research programme.

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Final word from Paul

This past July marked the end of the Specialty Wood Products (SWP) seven-year R&D programme. This programme has been very successful due to the significant support and collaboration of the industry partners: NZDFI teams have appreciated being a part of this. We have made excellent progress with our tree breeding and with assessing what species can be grown in New Zealand environments.

Collectively we have also worked with Scion and NZ Farm Forestry Association to de-risk New Zealand's wider opportunity to become a producer of diverse durable hardwoods and softwoods.

The SWP has demonstrated that there are a range of forestry options that forest growers and farm foresters can invest in. While more research and development is still needed, we now have improved genetics, site-species matching knowledge, growth models, wood processing options and emerging markets.

But it is only by planting new forests of these species at scale that New Zealand will realise the value of this research effort.

On a different note, I want to acknowledge the support and interest of one of our Marlborough landowner hosts David Dillon, who sadly died on 2^nd July 2023. I first got to know David when I joined the Marlborough branch of NZFFA in the 1980s. He was an early supporter of NZDFI and very keen to plant trials on his Waihopai valley farm, The Throne. Over the years we established a large array of both breeding and demonstration trials, making this the largest collective research trial site within the NZDFI’s network. David’s positive interest and enthusiasm, along with his chopper fly-overs,will be missed by the NZDFI team when making future site visits. Our condolences go to Sue, Tom and Hannah, who I know will continue to support the NZDFI's work at The Throne and further afield.

Paul Millen

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