Growth and form comparison, 2011 E. globoidea breeding populations
A growth and form assessment of two Wairarapa 2011 E.globoidea breeding trials has revealed minimal ‘G x E’ (genetics x environment) variation between two quite varying sites. The sites were Atkinson’s (South Wairarapa) and Juken NZ Ltd’s Ngamu site (near Masterton).
2011 E.globiodea at Atkinson's: one of our future seed orchards.
The practical implication of high correlations for these key characteristics, in terms of the NZDFI breeding programme, is that the best families are the same families at both sites. This gives our researchers confidence they can select elite individuals for commercial seed production for nurseries to grow improved stock that will perform on a range of different sites. Individual family heritabilities for DBH, form and straightness were calculated: correlation across sites was 0.72 for DBH, and 0.94 for straightness/form.
Wood quality testing is the next step for both these sites, using samples collected following routine thinning operations. Assessments will include growth strain, and quality traits (density, heartwood formation and extractives content).
Eight new trial sites for 2018
We have a total of eight new demonstration trials confirmed for planting this spring. Some trials are being planted at sites with landowners that already host our trials while there are new landowners with sites in Central North Island, Northland, Taranaki & Hawkes Bay regions. These trials will extend our research to and bring the total number of NZDFI trial sites to 39. The confirmed sites are:
- Kaingaroa Timberlands – Bay of Plenty
New trial site at Kapiro, Northland, where the landowners is Landcorp.
- Lake Taupo Forest Trust – Taupo
- NZ Redwood Company, Paparoa - Taumaranui
- Landcorp – Northland (Dargaville & Kerikeri)
- Landcorp - Central Hawkes Bay
- Thomson – Taranaki
- Dillon – Marlborough
- Marlborough District Council – Marlborough (clonal site only)
All but one of these sites will be planted with seedlings comprising a range of NZDFI’s preferred species. Some of the top-ranked families identified in NZDFI trials to date will be included – we have records of where all our seed was collected and so can always source more. Seedlings are now growing at Morgan’s Road Nursery, Blenheim, ready for deployment in September/October. In addition, we now have sufficient E.bosistoana clonal material, thanks to the propagation work at Proseed, to establish our first clonal trial on a site being provided by Marlborough District Council.
Permanent Sample Plot network expands
Over the 2017-18 summer, our summer-student field crew established another 22 Permanent Sample Plots in trials established in 2013 and 2014. A further nine PSPs were established in Juken NZ Ltd’s two E.bosistoana stands near Wairoa. The Juken NZ Ltd plantations cover 24 hectares in total, and have shown excellent growth.
PSP's in Juken NZ's Wairoa forest: 2013 and 2014 E. bosistoana.
Another ten existing PSPs were re-measured.
All the data from the PSPs, and details of our now 40,000 strong germplasm resource – i.e. trees in NZDFI trial sites – are held in our ‘Katmandoo’ database, developed with the help of the Michael Hassall at the Department of Agriculture and Forestry, Queensland.
The database has been maintained by Ruth McConnochie, NZDFI’s tree breeding specialist, and Kevan Buck, our database and mensuration expert. Dr Monica Sharman has now joined the NZ School of Forestry on a part-time basis, and will look after the NZDFI database, which is growing at an impressive rate. The database is the basis for all tree improvement and growth modelling. Monica is also assisting with wood quality assessments.
Flowering and seeding assessments of E.bosistoana and E.globoidea
We continue to carefully monitor flowering and seed development in two trial sites, Atknsons (Wairarapa, E. globoidea) and MDC Cravens Road (Marlborough, E. bosistoana). Both these sites have been selected have been identified for management as a seed stands to boost early improved seed supply from the NZDFI breeding programme.
A second flowering assessment of MDC Cravens Road 2009 and 2010 E. bosistoana breeding population was completed in January 2018. We found that the number of families flowering in the 2009 planting remains unchanged, only 51.6% of the families planted in this test are flowering. However the number of trees of these flowering families has increased from 13.6% to 17.4% of the total number of trees in the stand. In comparison, flowering in the 2010 planting continues to increase – both in the number of families and number of trees within these families.
Early stages of flowering
Copius E.globoidea flowers
Seed setting, E. globoidea
Achieving genetic gains
The delivery of genetic gain in future plantings will be achieved by selecting and propagating the best families in breeding populations. Open-pollinated seed collections from superior families will provide an interim seed supply until clonal seed orchards have been established and are producing seed. The NZDFI has produced breeding values for tree growth and stem form of individual families of both E.bosistoana and E. globoidea. These values were calculated from the assessment of progeny trials.
The delivery of genetic gain in future plantings will be achieved by selecting and propagating the best families in the breeding population. Ideally we need individuals of a range of families of different provenances to flower concurrently, whether within an original trial or within a seed orchard of grafted elite tree selections. If concurrent flowering doesn’t occur then controlled pollination may be required to ensure outcrossing.
The NZDFI Breeding Plan
Results from a 2017 assessment of Atkinson’s are available in Project Update July-December 2017.
Heartwood extractives are the key factor determining durability: innovative work at UCs Wood Technology Centre is using NIR spectroscopy to predict durability in young trees and find what genetic and environmental factors influence durability. We need to understand more about the variation in total extractives content between species, trees, and sites; the heritability of extractives content and composition; and how the composition of extractives affects durability.
Recent research aimed to validate whether total extractives content, predicted by the NIR spectroscopy technique we have developed, correlates with durability. We can measure durability by exposing timber samples to common rot-causing fungi, and then measuring how much mass they lose over time. Seven-year-old E. bosistoana heartwood samples (taken by coring trees at four NZDFI trial sites), and with known extractives content, were tested for durability (mass-loss) against two common rot fungi, a brown-rot and white-rot.
With the help of Dr Laurie Cookson, an Australian durability expert, we found that samples with high predicted extractives content did indeed have low mass-loss. The average mass loss for the E. bosistoana met at least the performance of a Class 1 (above-ground) rated species (Australian Durability Standard 5604 2005). Further, some of the E. bosistoana trees produced heartwood which showed no significant (<3%) mass-loss.
The figs above (click on them to enlarge) tell us about mass loss from seven-year-old E.bosistoana heartwood exposed to brown rot (left) and white rot (right) from two NZDFI trial sites, Cravens and Lawsons. We concluded that:
- NIR is able to select durable trees
- Young bosistoana is generally highly durable (<3% mass loss)
- Influence of site is significant.
A significant result was to find large variation (i) between trees and (ii) between sites. Variation between trees reinforces the need to select durable genotypes: we are learning that durability is heritable, so the earlier we can identify durable genotypes the sooner we can include them in NZDFI breeding selections. We believe these findings represent a significant step towards using this technique to select durable genotypes.
Some extractives are more potent than others in terms of their ability to resist rot fungi. Research to understand this ‘bioactivity’ of extractives is underway to:
- assess variation in chemical composition of heartwood extractives
- assess variation in the bioactivity of extractives
- identify key extractive compounds.
UC has set up a method to identify and quantify individual heartwood extractives. The next step has been to develop a way to test the bioactivity of different extractives against common rot fungi. We used the test technique on a range of E. bosistoana heartwood samples representing the genetic variation in the NZDFI breeding population. By combining the bioactivity test with what we know about quantities of extractives, we were able to investigate the bioactivity of those extractives. Our findings included:
- significant variation between trees in the bioactivity of bosistoana heartwood extractives against white rot and brown rot. This indicates potential for genetic selection.
- variation between sites in terms of influence on bioactivity was small.
Some 31 compounds have been quantified in E. bosistoana extractives, of which five have been tentatively identified. Work continues to ascertain the importance of extractives’ composition on durability. Once key compounds are identified we can directly assess them in the breeding population to identify superior trees.
Sawing timber for heartwood durability testing of E. bosistoana and E. globoidea
In-ground timber durability is traditionally assessed by placing small timber samples in ‘graveyards’ for many years and observing decay and failure. E. globoidea and E. bosistoana samples are being collected and will go into a new graveyard to assess their in-ground durability. As part of our SWP-funded work, we felled and sawed samples from 15-year old E. bosistoana and E. globoidea trees (two trees of each species) grown in the Marlborough Sounds. The samples have been fillet-stacked in the shade, covered, and left to season. Once seasoned they will be delivered to Scion in Rotorua, added to other similar age E. bosistoana and E. globoidea samples from Northland, and a new graveyard test will be established.
15-year-old E. bosistoana log.
Splitting log into two halves (cants) following slabbing off.
Sawing cants into quarters.
… then flitches
Colour-coded samples ready for storage and seasoning.
E.bosistoana for testing.
Wood quality sampling, Avery’s 2010 E. bosistoana planting
The Avery’s trial site in Marlborough is one of NZDFI’s driest sites, and is home to an E. bosistoana breeding trial planted in 2010. Growth has been relatively slow at the site, but the trees are now big enough for wood quality samples to be taken by coring. UC researchers recently took 1106 cores and assessed them for extractives content.
Avery's trial site.
The research team found that results from Avery’s were comparable to that obtained from other E. bosistoana breeding trials, although the trees were smaller but had higher extractives content at Avery’s. Findings included:
- high average extractives content for the Avery site (12.5%) compared with that at e.g. Martins site (6.0%). This is important because heartwood with high extractives tends to be more resistant to rot fungi
- variation between families (there are 42 bosistoana families at Averys) in heartwood diameter and extractives content. This finding in particular is consistent with other sites, and reinforces the possibility of selecting superior E. bosistoana genotypes to improve heartwood quantity and quality.
The data will now be used to select superior genotypes for propagation.
Graduates and new students
We have three graduating students, and four new student members of the Wood Quality team:
Dr Yanjie Li has successfully defended his PhD thesis: ‘Use of near infrared spectroscopy to predict wood traits in Eucalyptus species’. Yanjie developed a method to quickly screen durable eucalypts for natural durability and used it to assess NZDFI's first breeding populations comprising approximately 100 E. bosistoana families.
Satoru Kuwabara has completed his Honours thesis for his BForSci (Hon) degree titled ‘Prediction of extractive content of E. globoidea heartwood using near infrared spectroscopy’.
Niklas Schroettke has completed a MSc for the University of Hamburg. Together with Marlene Cramer (TU Dresden, Germany) and Diego Russo (Uni Calabria, Italy), Niklas worked during his internship with the Wood Quality research group on UC's NZDFI wood quality programme.
New to the NZDFI wood quality team:
Ebenezer Iyiola (PhD candidate) will focus on assessing NZDFI's E. globoidea breeding population for wood quality traits, focusing on wood quality of E. globoidea.
Seol-Jong Kim (PhD candidate) will soon embark on a population-genomic and taxonomic study focusing on Eucalyptus.
Chamira Rajapaksha (PhD candidate) is aided by a scholarship from the Government of Sri Lanka. Chamira’s main interest is in the essential oils of eucalypts. Although not necessarily essential for a durable eucalypt industry, her research is highly welcome and will add to our knowledge of the NZDFI species.
Harry Ferguson is a BE (Hons) student in Forest Engineering. He is working on heartwood traits in the Martin (2009) E. bosistoana breeding population.
Proseed continue to address the many challenges associated with propagating eucalypts, and are moving slowly but surely up a steep learning curve. There has been significant success with E.bosistoana, while E.globoidea is proving harder to crack. The Proseed team now has successfully propagated around 700 different E.bosistoana clones from selections made from Woodville Nursery to deploy in a clonal-only site being provided by the Marlborough District Council. in Marlborough. A full update on the work was presented by Proseed’s Paul Schroeder at the June 2018 workshop.
Rooted cuttings in Proseed’s new propagation facility, Amberley.
Inspecting E. bosistoana clonal stock produced by Proseed.
New students to begin eucalypt health research in 2018
We recently advertised for two new PhD students: the selection process is underway and we hope to have our new students ready to start work by the spring. The two research areas are: (i) Eucalypt variegated beetle (EVB) host preferences and biological control (ii) relating durable eucalypt pest tolerance to foliar chemistry.
Dr Huimin Lin successfully defended her PhD thesis earlier this year, looking at the impact of the timing and severity of insect defoliation. Huimin's work was reported in more detail in the July-December 2017 Project Update.
Site-specific yield and survival models developed
Serajis Selakin at work in McNeill's trial the Hawke's Bay.
PhD candidate Serajis Selakin has submitted his thesis, having completed site-specific yield and survival modelling for E.bosistoana and E.globoidea. Serajis’ work included creating detailed topographic models of trial sites and analysing the impact of micro-site factors such as aspect, exposure and soil properties on tree growth. Serajis completed yield and survival models for E.bosistoana and E.globoidea, concluding that wind exposure and topographic protection are the two most important predictors for each species. E.bosistoana also appears relatively sensitive to soil moisture levels.
Serajis also developed a preliminary mature stand growth model for E.globoidea, thanks to input from Dr Dean Meason at Scion.
A new PhD candidate, Daniel Boczniewicz, will begin work in October 2018, researching heartwood taper and volume modelling in relation to site.
2018 Workshop presentations available
Much of the research described in this Project Update was presented at our June 2018 'Durable Eucalypts on Drylands' workshop. All the presentations are available here.
Final Word: Paul Millen
In June 2018, the NZDFI celebrated its 10th anniversary. The milestone was marked by an excellent research workshop at the University of Canterbury, the third such gathering in the past few years. We had the usual high-calibre international participants and reinforced the tremendous breadth and depth of work going into the NZDFI programme. The workshop featured presentations from the first cohort of NZDFI PhD and MSc student researchers, several of whom are now graduating. Congratulations and thanks for the hard work and dedication by this great team and their supervisors. We have a new team of research students either already underway or about to start, so progress continues apace at the University of Canterbury.
Central Government’s One Billion Trees programme is a significant opportunity for the forestry sector. This includes NZDFI. Our vision is to plant 100,000 ha of durable eucalypts by 2030 to supply a multi-regional durable hardwood industry in NZ’s east coast regions. Earlier in 2018 we circulated a consultation paper about developing a regional strategic plan to achieve this. Many thanks to all those who provided such useful feedback. As a direct result, the NZDFI was invited to submit an Expression of Interest (EoI) to the Government’s Provincial Growth Fund (PGF). We received the exciting news that our EoI had been accepted and we are now developing an application to the PGF for a multi-million dollar expansion to our research programme. We have made a lot of progress in ten years: the support of the PGF will ensure we can build our capability and so accelerate research and scale up production of elite planting stock.
Thanks to everyone for their continued support.
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