Pulping and papermaking potential of plantation-grown E. deglupta from PNG

1997

Pulping and papermaking potential of plantation-grown E. deglupta from PNG

A long-awaited synthesis of the pulping and papermaking potential of plantation-grown E. deglupta was published in 1997.4A quote of the abstract follows:

“The papermaking properties of both unbleached and bleached sulphate as well as unbleached neutral sulphite semichemical (NSSC) pulps were evaluated to determine the effect of age on pulpwood quality in Eucalyptus deglupta. All age classes of pulpwood could be pulped readily by the sulphate process and good yields of pulp were obtained. With increasing age and constant alkali, higher screened pulp yields were produced at lower Kappa numbers. As the age increased, the volume of wood, size of plantation and amount of alkali required to produce one tonne of sulphate pulp decrease. Sulphate pulps had very good papermaking properties which will be adequate for a wide range of unbleached paper grades. High brightness sulphate pulps were readily produced using a CEHD [C: Chlorination; E: Extraction; H: Hypo; D: Chlorine Dioxide] bleaching sequence from unbleached pulps with Kappa numbers less than 35. These bleached pulps were suitable for the manufacture of a wide range of bleached paper products. NSSC pulps were suitable for use in corrugating medium and in a variety of other paper and paperboard products especially if pulped to a Kappa number of about 100. Eucalyptus deglupta pulpwood from plantations at any age between 3 and 20 years was very suitable for chemical and semichemical pulp production. The 10- to 12-year-old trees were the preferred age classes for sulphate pulping based on the combination of early harvesting for economic reasons and acceptable pulping and papermaking properties.”

2003

Molecular studies on Eucalyptus subgenus Minutifructis

Eucalyptus subgenus Minutifructis (sensu Brooker 2000) (replacing the informal subgenus ‘Telocalyptus’, one of eight informal subgenera of Eucalyptus sensu Johnson 1976) comprises four ‘tropical box’ species and is characterised by compound terminal inflorescences (rare in eucalypts), very small buds and fruits and discolourous leaves with densely reticulate veins.5Minutifructis is divided into two sections: Equatoria, the name referring to the equatorial distribution in the Philippines, Indonesia and PNG of the lone species E. deglupta in the section, and Domesticae referring to the occurrence on the Australian mainland of all three species comprising the section, E. brachyandra in northern Western Australia, E. howittiana in north eastern Queensland and E. raveretiana in central-eastern Queensland.

Before 1976 Pryor and Johnson (1971) had divided these four species between two sections of subgenus Symphyomyrtus: section Equatoria, series Degluptae (E. deglupta, E. raveretiana and E. brachyandra) and section Howittianae (E. howittiana). In 1988 Chippendale followed this arrangement describing two

4 Phillips F H, Logan A F and Harries E D 1997 The pulping and papermaking potential of plantation-grown Eucalyptus deglupta from Papua New Guinea. Part 2. Sulphate and NSSC pulps from wood of various ages. Earlier articles included: Phillips F H, Logan A F and Balodis V 1979 Suitability of the tropical forest for pulpwood: mixed hardwood, residues and reforestation species. Tappi 62(3):77-81 and, Logan A F 1981 Pulping of tropical hardwood reforestation species. CSIRO Australia, Division of Chemical Technology, Research Review. 5 Johnson L A S 1976 Problems of species and genera in Eucalyptus (Myrtaceae). Plant Systematics and Evolution 125:155-167; Brooker M I H 2000 A new classification of the genus Eucalyptus L’Her. (Myrtaceae). Australian Systematic Botany 13: 79-148.

series on the basis of differences in inflorescence and fruit morphology: Myrtiformes (corresponding to Pryor and Johnson’s 1971 section Equatoria series Degluptae) and Howittianae.

6

Papers by Sale et al. (1993, 1996) and Steane et al. (2002) indicated that Minutifructus should not be ranked as high as in a separate subgenus and instead the species be nested within subgenus Symphyomyrtus. 7 Molecular data presented by Steane et al. (2002) and Whittock et al. (2003) support the earlier opinion of Pryor and Johnson (1971) that species from Minutifructus evolved from within subgenus Symphyomyrtus8 leading to the hypothesis that E. deglupta evolved outside Australia from a symphyomyrt ancestor possibly during northwards and westwards migration of fragments of the Australian plate and long-distance dispersal by wind and updrafts from volcanoes along the western margin of the “Pacific rim of fire”.

This opinion is supported by some current hybridisation successes. Normally crosses between eucalypt species from different major subgenera are not successful. Generally, the more closely related eucalypt taxa are, the more likely they will make successful interspecific crosses. Manipulated interspecific crosses of E. deglupta from Minutifructus and two species of subgenus Symphyomyrtus section Latoangulatae (sensu Brooker 2000), E. deglupta♀ x E. pellita♂ and E. deglupta♀ x E. urophylla♂, were successful at PICOP in the Philippines.

Whittock et al. 20039produced a strict consensus cladogram of species from Minutifructus within subgenus Symphyomyrtus (figure on next page). In this figure the branch hierarchy supports E. deglupta (section Equatoria) and E. brachyandra (section Domesticae sensu Brooker) being more closely aligned with sections Exsertaria (SE), Latoangulatae (SL) and Maidenaria (SM) in clades B and C. E. howittiana and E. raveretiana (also both section Domesticae) appear to have an ancestor in common with sections Bisectae (SB part 1), Adnataria (SA) and Dumaria (SD) in Clade A.

6 Chippendale G M 1988 Eucalyptus, Angophora (Myrtaceae), Flora of Australia 19. Australian Government Publishing Service, Canberra; Pryor L D & Johnson L A S 1971 A Classification of the Eucalypts. Australian National University, Canberra. 7 Sale M M, Potts B M, West A K and Reid J B 1993 Relationships within Eucalyptus using chloroplast DNA. Australian Systematic Botany 6:127-138; Sale M M, Potts B M, West A K and Reid J B 1996 Relationships within Eucalyptus using PCR-amplification and southern hybridisation of chloroplast DNA. Australian Systematic Botany 9:273-282. 8 Steane D A, Nicolle D, McKinnon G E, Vaillancourt R E and Potts B M 2002 Higher level relationships among the eucalypts are resolved by ITS-sequence data. Australian Systematic Botany 15:49-62. 9 Whittock S, Steane D A, Vaillancourt R E & Potts B M 2003 Molecular evidence shows that the tropical boxes (Eucalyptus subgenus Minutifructis) are over-ranked. Transactions of the Royal Society of South Australia 127(1):27-32.

This figure from Whittock et al. 2003 shows the “Symphyomyrtus” part of a strict consensus cladogram from cladistic analysis of internal transcribed spacer (ITS) data showing positions of species from Minutifructus within subgenus Symphyomyrtus. Bootstrap percentages over 50% and branch lengths (from a single tree) are shown respectively above and below the internal branches. A, B, C and D are clades of subgenus Symphyomyrtus. Clade A comprises sections Adnataria (SA), Bisectae (SB) (part I), Platysperma (SP), Dumaria (SD), as well as E. howittiana and E. raveretiana from subgenus Minutifructus; Clade B sections Latoangulatae (SL) and Exsertaria (SE); Clade C sections Maidenaria (SM) and Racemus (SR); Clade D sections Inclusae (SI) and Bisectae (SB) (part II). ME = Minutifructis section Equatoria; MD = Minutifructis section Domesticae. Origins: E. howittiana 1 MS1999 Atherton Queensland, E. howittiana 2 DN2526 Northern Ranges, Queensland, E. raveretiana 852255 Australian Botanic Garden Mount Annan NSW, E. deglupta 1 Philippines CSIRO seed lot 19492-1, E. deglupta 2 New Britain? (Bulolo PNG CSIRO seed lot 19790B), E. deglupta 3 New Britain? (Bulolo CSIRO seed lot 19791B), E. deglupta 4 A cultivated specimen from the Botanical Gardens in Darwin (origin unknown).

The seed lots of E. deglupta attributed to Bulolo, whether collected there from the Seed Orchard, or from within and around the town of Bulolo, are most likely of New Britain origin. If from the Seed Orchard, the origin is more specifically from Keravat plantations of local provenance in East New Britain.

There is an anomaly in that E. deglupta 2 and 3 probably collected from the same locality in Bulolo, given their consecutive CSIRO seed lot numbers, branch at different levels. That E. deglupta 3 branches at the same level as 1 and 4 suggests the anomalous one is 2. GenBank sequences of ITS indicate E. deglupta 2 differs from 3 by four substitutions and one insertion. Section Equatoria (ME), with its three E. deglupta (1,3 and 4, excluding the apparently anomalous 2), falls neatly and separately in the middle 338

of the very large subgenus Symphyomyrtus. E. raveretiana and E. howittiana 1 and 2 of section Domesticae (MD) however are imbedded in Clade A of subgenus Symphyomyrtus. E. howittiana 1 and 2 from two different localities at Atherton and Northern Ranges respectively in Queensland branch at different levels. E. brachyandra branches earlier than E. deglupta 1, 3 and 4 and, like the latter, does not fall within any of the four clades A, B, C and D of subgenus Symphyomyrtus.

Among Eucalyptus only five species have been documented to have a coralline calyptra with externally visible, weakly fused petals with overlapping edges that do not form a single structure. Four suture lines appear as a cross like the cross on a hot cross bun. Only three of these species, E. brachyandra, E. guilfoylei and E. microcorys, are within or near subgenus Symphyomyrtus. (Brooker (2000) placed E. guilfoylei by itself in Eucalyptus subgenus Cruciformes because of the prominent cross-like suture on the calyptra.) This morphological character in E. brachyandra is sufficient to distinguish it from the other three species in Minutifructus and may indicate it is older in the evolutionary scale than E. deglupta, E. howittiana and E. raveretiana. In the evolutionary context it is also worth noting that the petal edges are obvious in the Patagonian fossil flower buds dated from the early Eocene at about 51.9 million years ago.10

There are many uncertainties in dating eucalypt evolution using molecular phylogenies. The exact geological age relationship of all four species in Minutifructis has yet to be determined. In the Whittock et al. 2003 fully-labelled ITS tree given above, E. brachyandra is the taxon shown arising from node C of the following Figure 3 from Crisp et al. 2004.11If all four species are added to the branch from node C, then node C becomes an estimate of the age of the Minutifructis clade. Node C is estimated by Crisp et al. 2004 in their Table 4 at 38-26 million years old (their ‘most recent’ column) and 45-26 million years old (their ‘earliest’ column) but in their Figure 3 the node is shown at about 38 million years of age. Ladiges and Udovicic 200512 estimate the E. deglupta node 2 to have a geological age of about 8 million years. This agrees with the geological model for the geographic region in which the species occurs. Isolation of E. brachyandra in the Kimberley in northwest Australia is a much older (earlier) event if it is assumed to have the same age as node C (38 million years).

10 Gandolpho M A, Hermsen E J, Zamaloa M C, Nixon K C, González C C, Wilf P, Cúneo N R and Johnson K R 2011, Oldest known Eucalyptus fossils are from South America, PloS ONE 6(6):e21084 doi:10.1371/journal.pone.0021084. Epub. June 28, 2011. 11 Crisp M, Cook L and Steane D 2004 Radiation of the Australian flora: what can comparisons of molecular phylogenies across multiple taxa tell us about the evolution of diversity in present-day communities? Philosophical Transactions of the Royal Society of London B 359:1551-1571. 12Ladiges P Y and Udovicic F 2005 Comment on the molecular dating of the age of eucalypts. Australian Systematic Botany 18:291-293.

Chronogram of eucalypts sourced from Crisp et al. 2004 loc cit. that compares estimates of divergence times (million years ago (Mya), scale on the right) among eucalypt lineages based on climatic and tectonic events, and assuming the basal divergence between the eucalypts sensu lato (arrow at node A) and Arillastrum at 70 Mya based on calibration from a vicariance event. The grey bars over the nodes indicate there is a range in the estimates because of variation in topology and choice of method and calibration points. The dating of the Patagonian fossils at about 51.9 Mya and their placement in Symphyomyrtus could be accommodated in this figure without altering the structure at the younger nodes. The dashed lineages are extra-Australian. Symbols indicate the biome in which each terminal taxon occurs: Ω, aseasonal wet; Δ, monsoonal; Ο, southwest temperate; +, southeast temperate;§, eremean; * other. Node B: Allosyncarpia (monsoonal) versus Eucalyptopsis (wet tropics); Node C: Ancestor of E. deglupta clade (Southeast Asia) diverges from Australian sister taxon; Node E: divergence of E. urophylla (Timor) clade from Australian sister taxon. The four asterisks are equivalent E. deglupta numbers 1, 3 4 and 2 (left to right) from Whittock’s figure given earlier. The triangle immediately to the left of the asterisks is equivalent to E. brachyandra from the same source.

Relationships of the four tropical boxes within subgenus Symphyomyrtus. Nodes 1 and 2 are supported by both morphology and cpDNA data. Node C is as in Figure 3 in Crisp et al. 2004 given above and possibly also supported by morphological data (for example the cross-like suture on the calyptra of E. brachyandra). Q, Queensland; NG, New Guinea; P, Philippines; K. Kimberley. Node C is shown by Crisp et al. 2004 in their Figure 3 at about 38 million years of age The E. deglupta node 2 is estimated by Ladiges and Udovicic 2005 to have a geological age of about 8 million years. Isolation of E. brachyandra in the Kimberley in northwest Australia is a much older (earlier) event if it has the same age as node C (38 million years).

A more recent paper by Grattapaglia et al. 201213employed a Splitstree4 analysis14from genome-wide genotyping of 94 species in Eucalyptus sensu stricto to present a different way of viewing the phylogenetic network. Most of the industrial eucalypt plantations of the world are based on just a few eucalypt species. Nine are listed in the Splitstree figure below in red. They occur in only two main poorly-differentiated clades and in only three sections - Latoangulatae and Exsertaria (“Clade B”) and Maidenaria (“Clade C”). Of those nine species, the three in bold red and with an asterisk, one from each section, have been the subject of detailed genomic studies.

A Splitstree4 summary analysis of 94 species in Eucalyptus sensu stricta is shown. 8,354 DArT markers from genome-wide genotyping were used. The DArT phylogeny provided more resolution within major clades than had been obtained previously. The results largely agreed with traditional taxonomy and ITS-based phylogenies presented earlier, but I have removed from this figure reference to Minutifructis as a sub-genus on the basis of the earlier discussion about it being over-ranked. Instead, the individual species have been named and nested within subgenus Symphyomyrtus in the locations previously occupied by sections Domesticae and Equatoria of Minutifructis. More data are required to determine whether the association of E. raveretiana and E. howittiana (section Domesticae) with sections Dumaria and Adnataria is real or an artifact (dashed oval around “Clade A” in the figure). E. brachyandra was not included in this analysis. The remainder of the figure was sourced unchanged from Grattapaglia et al. 2012 loc cit.

13 Grattapaglia D, Vaillancourt R E, Shepherd M, Thumma B R, Foley W, Külheim C, Potts B M and Myburg A A 2012 Progress in Myrtaceae genetics and genomics: Eucalyptus as the pivotal genus. Tree Genetics and Genomes 8(3):463-508. 14 Hudson D H and Bryant D 2006 Application of phylogenetic networks in evolutionary studies. Molecular Biology and Evolution 23(2):254-267.

2007

Breeding programme for E. deglupta in the Solomon Islands

In the Solomon Islands, an active breeding program for E. deglupta in the 2002-2007 period resulted in the selection of 40 plus trees which were progeny tested and the trial culled to a Seedling Seed Orchard with 20 families in 4 replications.

2008

E. deglupta Seed Orchard Bulolo

This orchard had been used for over 35 years. Through fires and vandalism, the number of trees has diminished over time (photographs on the next page). An attempt under an ACIAR project to establish a new clonal seed orchard at Bulolo in 2006 comprising 30 clones with four ramets per clone was unsuccessful.

2011

Herbarium collections of E. deglupta by K Damas

From 20 April to 5 May 2011, K Damas from the National Herbarium in Lae travelled in West New Britain in the vicinity of Kimbe, Biala and Talasea, collecting over 60 specimens from the Dagi, Ru, Berima, Evula, Savula, Kuludagi and Kapaluk Rivers and Moyou Creek which have been deposited in Lae with duplicates where available sent to herbaria in Bogor and Melbourne.

Above: Recent seed collection in the E. deglupta seed orchard Bulolo. (Photograph: D Spencer) Right and below: Perfectly grafted trees at Bulolo about 35 years old in 2008. (Photographs: via Steve Midgley, CSIRO, Canberra)

Open Bay Timber Company

In September 2011, Open Bay Timber Limited (OBT) was granted Forest Stewardship Council (FSC) certification of 11,770 ha of plantation forests under management at Open Bay, New Britain, mainly E. deglupta (photograph below).

2013

E. deglupta chloroplast genome sequenced

In November 2013 came the announcement that the complete chloroplast genome of E. deglupta had been sequenced.15Comprising 160,177 base pairs, the genome is in the public domain at the National Centre for Biotechnology Information (NCBI) (Reference Sequence NC_022399).16

Parts of the record available at the NCBI for the complete chloroplast genome of E. deglupta. These are the instructions in a gene that tell the cell how to make a specific protein. A, C, G, and T are the “letters” of the DNA (Deoxyribonucleic Acid) code, also known as “bases”. They stand for the chemicals adenine (A), cytosine (C), guanine (G), and thymine (T) that make up the nucleotide bases of DNA. Adenine pairs with thymine, and cytosine pairs with guanine. There are 160177 bases in the complete chloroplast genome for E. deglupta. It would take 46 pages like the one on the right to print out the whole genome!

15 Bayly M J, Rigault P, Spokevicius A, Ladiges P Y, Ades P K, Anderson C, Bossinger G, Merchant A, Udovicic F, Woodrow I E and Tibbits J 2013 Chloroplast genome analysis of Australian eucalypts – Eucalyptus, Corymbia, Angophora, Allosyncarpia and Stockwellia (Myrtaceae). Molecular Phylogenetics and Evolution 69(3):704-716. 16 Available at: NCBI; https://www.ncbi.nlm.nih.gov/genomes/GenomesGroup.cgi?opt=plastid&taxid=2759

The GenBank sequence database is an open access, annotated collection of all publicly available nucleotide sequences and their protein translations. This database is produced and maintained by the National Center for Biotechnology Information as part of the International Nucleotide Sequence Database Collaboration.

The eucalypts are predominantly out-crossers with hermaphroditic animal-pollinated flowers, eucalypts are highly heterozygous and display pre- and post-zygotic barriers to selfing to reduce inbreeding depression for fitness and survival.

The evolutionary history of the Eucalyptus genome is marked by a lineage-specific palaeo-tetraploidy event newly revealed by genomic analysis, superimposed on the earlier palaeo-hexaploidy event shared by all eudicots.17The whole-genome duplication (WGD) is estimated by Bayly and co-authors to have occurred about 109.9 (105.9–113.9) million years (Myr) ago in a Gondwanan ancestor around the time when Australia and Antarctica began to separate from East Gondwana. This WGD event is considerably older than those typically detected in other rosids.

18

In 1971, Pryor and Johnson proposed an informal taxonomic classification of all eucalypts, which has become widely accepted as portraying the natural groupings within the genus. However, there have been subsequent modifications, notably the upgrading of Corymbia to the level of genus by Hill and Johnson in 1995 and subsequent downgrading it back to a subgenus of Eucalyptus by Brooker in 2000. E. cloeziana did not fit easily into established subgenera due to its unique operculum structure and thus remained the monotypic member of the subgenus Idiogenes. However, E. cloeziana is recognized by several authors as having a close affinity with the subgenus Monocalyptus. Phylogenetic assessment of the genus has supported E. cloeziana's position as basal to Monocalyptus19 and its subgeneric status was maintained in the formal classification proposed by Brooker in 2000. In a revision of white mahoganies (Monocalyptus, series Acmenoideae), Hill in 1999 proposed to split E. acmenioides into several species.

Reports of both natural and manipulated hybridization are common between eucalypts (Eucalyptus, Corymbia and Angophora), with 289 of the 528 species (55 %) reviewed by Griffin et al. reported to hybridize with at least one other species.20Subgeneric classification is thought to delimit the extent of

17

Bayly et al. loc. cit. 18 The “rosids” are a large clade of flowering plants. It includes about 70,000 species, more than a quarter of all angiosperms. The rosids are divided into 17 orders. These orders together make up about 140 families. 19 For example: Sale M M, Potts B M, West A K, and Reid J B 1993 Relationships within Eucalyptus using chloroplast DNA. Australian Systematic Botany 6:127-138. 20 Griffin A R, Burgess I P and Wolf L 1988 Patterns of natural and manipulated hybridisation in the genus Eucalyptus L’Hérit. – a review. Australian Journal of Botany 36:41-66.

hybridization in eucalypts. Hybridizing taxa largely occur between parapatric or sympatric populations of closely related species found within the same series or section. The only substantiated case of hybridization between subgenera occurs from artificial crosses between E. deglupta (subgenus Telocalyptus = Minutifructis) and taxa from the subgenus Symphyomyrtus (see earlier). These hybrids were reported by Griffin et al., to produce weak seedlings that were unlikely to survive to sexual maturity. However, molecular phylogenetic analysis of the chloroplast genome and the nuclear ITS region in eucalypts has placed the subgenus Telocalyptus = Minutifructis within the Symphyomyrtus clade, hence suggesting Telocalyptus = Minutifructis, and thus E. deglupta, be incorporated into Symphyomyrtus.21 This highlights the existence of inconsistencies that still reside in the taxonomic classification within the Eucalyptus genus.

ACIAR Project “Facilitating the availability and use of improved germplasm for forestry and agroforestry in Papua New Guinea”

The rationale for this Project was to support community tree planting programs in PNG by making available improved germplasm for a range of high value timber species as well as some non-timber species, and by training rural communities in the propagation and deployment of this material. Additionally, new eucalypt hybrids with potential for plantation forestry in PNG and north Queensland also formed part of the strategy. The three-year project started in August 2005 involving Partner country institutions; Papua New Guinea Forest Research Institute, The Foundation for People and Community Development, Queensland Department of Primary Industry Agency for Food and Fibre Science and CSIRO.

In PNG, the Project was to develop improved knowledge and establish germplasm sources for 11 target tree species; Dracontomelon dao (walnut), Calophyllum euryphyllum (kalophilum), Endospermum medullosum (basswood), Tectona grandis (teak), Pometia pinnata (taun), Eaglewood (Gyrinops ledermanii) (eaglewood), Santalum macgregorii (PG sandalwood), Santalum album (Indian sandalwood), Acacia crassicarpa (crassicarpa), Eucalyptus pellita (pellita) and E. deglupta (kamarere). An attempt was to be made to develop a hybrid between E. deglupta and E. pellita. In Australia, a series of hybrid combinations was to be trialled in Queensland.

21 Sale et al. loc cit. and Steane D A, McKinnon G E, Vaillancourt R E and Potts B M 1999 ITS sequence data resolve higher-level relationships among the eucalypts. Molecular Phylogenetics and Evolution 12:215-223.

A final report was prepared by Brian Gunn and published by ACIAR in November 2013.22 No significant progress was made at the time on advancement of germplasm supplies or the development of novel eucalypt hybrid combinations under Objective 3: “To develop Eucalyptus deglupta germplasm”.

The lessons from the almost 50 years of experiences with breeding E. deglupta in PNG, the Philippines and elsewhere are that not only in-situ stands containing valuable genetic resources continually at risk, but there may be even greater threats to economically-valuable ex-situ products of ongoing breeding programmes such as provenance block plantings, seed orchards, progeny trials, clone banks, hybrid trials and the like as well as vital associated records and documentation.

2014

Reference genome of E. grandis released

On 19 June 2014, an international consortium of researchers, including US Department of Energy Joint Genome Institute (DOE JGI) scientists23, released the reference genome of E. grandis. The effort to sequence and analyse the 640 million base pair genome of the species employed more than 80 research scientists from 30 institutions in 18 countries. Results were that Eucalyptus has 36,376 genes, 10,049 clusters, and 30,341 of the genes in those clusters

Among the more than 36,376genes found in Eucalyptus (nearly twice as many as in the human genome), the researchers discovered many that influence the production of secondary cell wall material that can be processed for pulp, paper, biomaterials and bioenergy applications. Comparative analysis of the complex traits associated with the Eucalyptus genomeoffers new opportunities for accelerating breeding cycles for sustainable biomass productivity and optimal wood quality and for adaptation to climate change. The genome data provide a diagnostic tool for understanding the basis of extremely fast growth

22 Gunn B 2013 Facilitating the availability and use of improved germplasm for forestry and agroforestry in Papua New Guinea. Project FST/2004/009, Final Report No. FR2013-17. Australian Centre for International Agricultural Research (ACIAR), Canberra. 41pp. 23 Myburg A A, Grattapaglia D, Tuskan G A, Hellsten U, Hayes R D, Grimwood J, Jenkins J, Lindquist E, Tice H, Bauer D, Goodstein D M, Dubchak I, Poliakov A, Mizrachi E, Kullan A R K, Hussey S G, Pinard D, van der Merwe K, Singh P, van Jaarsveld I, Silva O B Junior, Togawa R C, Pappas M R, D Faria D A, Sansaloni C P, Petroli C D, Xiaohan Yang, Ranjan R, Tschaplinski T J, Chu-Yu Ye, Ting Li, Sterck L, Vanneste K, Murat F, Soler M, Clemente H S, Saidi N, Hua Cassan-Wang, Dunand C, Hefer C A, Bornberg-Bauer E, Kersting A R, Vining K, Amarasinghe V, Ranik M, Naithani S, Elser J, Boyd A E, Liston A, Spatafora J W, Dharmwardhana P, Raja R, Sullivan C, Romanel E, Alves-Ferreira M, Külheim C, Foley W, Carocha V, Paiva J, Kudrna D, Brommonschenkel S H, Pasquali G, Byrne M, Rigault P, Tibbits J, Spokevicius A, Jones R C, Steane D A, Vaillancourt R E, Potts B M, Joubert F, Barry K, Pappas G J, Strauss S H, Jaiswal P, Grima-Pettenati J, Salse J, van de Peer Y, Rokhsar D S andSchmutz J 2014 The genome of Eucalyptus grandis. Nature 510:356362. (19 June 2014)

rates and optimum wood and fibre properties. Eucalypt trees are grown on over 40 million hectares in 100 countries across six continents.

The extensive catalogue of genes will allow eucalypt breeders to rapidly adapt genotypes for many purposes. The genome data are available publicly through the DOE JGI’s comparative plant genomics portal known as Phytozome (http://bit.ly/Phytozome-Eucalyptus).

2015

Article on E. deglupta in “The Forester”

On page 11 of the June 2015 issue of The Forester (left), the Editor posed the question “Is this the only eucalypt to occur naturally in the northern hemisphere?”

I submitted a detailed reply in the following issue (August 2015) (below).24

24 Davidson J 2015 Eucalyptus deglupta. The Forester, June 2015:28-31

2017

E. deglupta in the Adelaide Botanic Garden

The Botanic Gardens and State Herbarium of South Australia planted two trees in the Botanic Park arboretum in 2016. In 2017 four more were added to the Park and one in Adelaide Botanic Garden.

2018

E. deglupta in “Trees for Life in Oceania”

E. deglupta was among 53 species, five of them eucalypts, that featured in this publication in 2018. 25The following points were made about the species.

25 Davidson J, Gunn B and Spencer D 2018 Eucalyptus deglupta. Pages 104 – 107 in Thomson L, Doran J and Clarke B (eds) 2018 Trees for life in Oceania: conservation and use of genetic diversity. ACIAR Monograph No. 201. Australian Centre for International Agricultural Research: Canberra. 278 pp.

E. deglupta is a fast-growing hardwood suitable for planting in the lowland tropics where many other species of eucalypt do not thrive. It generally has excellent form, is easy to propagate from cuttings and is relatively free of many of the diseases that afflict eucalypts grown in the tropics. Disadvantages include its poor coppicing ability, its requirement for fertile well-drained sites for optimum growth, and fire and cyclone susceptibility.

There is considerable diversity among trees from different regions in terms of morphology, stem form, wood properties and resistance to pests and diseases. Breeding programs have capitalised on selection for fast growth, more straight and cylindrical stems and higher and more uniform wood density in plantation-grown wood destined for pulping. Selection of particular provenances and hybridisation of these with other tropical eucalypts have improved resistance to foliar leaf spot diseases and stem borers.

Results of early provenance testing showed the best performing provenances to be the north coast of New Britain PNG and from southeast of Bislig Bay, Mindanao. There is considerable variation among regions in morphology, stem form, wood properties and resistance to pests and diseases. Indonesian provenances have not been sufficiently tested against Philippines and PNG provenances.

In the immediate future, the importance of E. deglupta lies in capturing its fast growth, excellent form, ease of propagation by cuttings and almost complete freedom from the leaf spot diseases that afflict most other eucalypts when grown in the lowland humid tropics, by developing hybrid combinations with such species as E. urophylla, E. wetarensis (tolerance of a more diverse range of site quality, higher wood density and some disease tolerance) and New Guinea sources of E. biterranea (higher wood density, good disease tolerance). E. deglupta x E. pellita was initially very successful in Mindanao, Philippines,

where the best hybrids were clonally propagated using cuttings. The following populations were expected to provide useful base/breeding populations:

Geshes Clonal Seed Orchard, Bulolo, PNG subline (seed is available from 9 ramets of 3 surviving clones) North Coast, East New Britain, PNG subline. (New collections are required.) North Coast, West New Britain, PNG subline. (New collections are required.) West Sepik, PNG subline. (New collections are required.) West Papua, Indonesia subline (New collections are required from surviving depleted stands in the two natural locations.) Takalar Seedling Seed Orchard, South Sulawesi, Indonesia subline (present status needs to be determined, otherwise new collections are required). Kenangan Seedling Seed Orchard, East Kalimantan, Indonesia subline (present status needs to be determined, otherwise new collections are required). Mindanao, Philippines subline (new collections are required from natural stands surviving in New Bataan, Bislig, Monkayo and Pasian localities).

The basic breeding strategy shown in the upper figure on the previous page is still relevant. If PNG wishes to start up the breeding programme again with E. deglupta, the basic strategy would need to expand into a more detailed breeding plan like the one given on the bottom of the previous page that would run over several generations (3 generations over 15 – 20 years are shown).

Knowledge of the E. grandis nuclear genome has already paved the way for detailed studies of genes associated with wood production, and for development of a new system for genotyping eucalypt individuals using genome-wide markers that could be widely applied to population studies and tree breeding programmes.

If full advantage is taken of the eucalypt genomes, marker assisted selection could be undertaken on juvenile seedling and clonal material grown in a glasshouse to rapidly turn over generations without recourse to field trials of adult material. Such a strategy would enable elements in the above breeding plan to be collapsed perhaps by a factor of ten in the time taken to produce results from the selections at each step.

2019

Our book on “Eucalypt Domestication and Breeding” has remained relevant. It often is given still as a reference in articles and publications on eucalypts. It remains available today from the publisher for £80.00. (In July 2019, £80 = US$100 = A$144 approximately.)

Second hand paperback copies also turn up on ebay and Amazon from time to time and command a rather high price. One such advertisement in June 2019 is shown here for a used copy priced at A$163.95!

Geological time line with reference to some eucalypts

With some new information it was possible to expand on the geological time line with reference to some eucalypts that I had presented in “The Forester” in 2015.26

26 Sources include: Ladiges P Y, Udovicic F and Nelson G 2003, Australian biogeographic connections and the phylogeny of large genera in the plant family Myrtaceae, Journal of Biogeography, 30(1), 989—998, Crisp M D, Cook L G and Steane D A 2004, Radiation of the Australian flora: what can comparisons of molecular phylogenies across multiple taxa tell us about the evolution of diversity in present day communities?, Philosophical Transactions of the Royal Society London, B 359, 1151-1571, Ladiges P Y and Udovicic F 2005, Comment on molecular dating of the age of eucalypts, Australian Systematic Botany, 18, 483-487, Boland DJ, Brooker MIH, Chippendale G M, Hall N, Hyland B P M, Johnston R D, Kleinig D A, McDonald M W and Turner J D 2006, Forest Trees of Australia, CSIRO, Melbourne, Gandolpho M A, Hermsen E J, Zamaloa M C, Nixon K C, González C C, Wilf P, Cúneo N R and Johnson K R 2011, Oldest known Eucalyptus fossils are from South America, PloS ONE 6(6):e21084 doi:10.1371/journal.pone.0021084. Epub. June 28, 2011.

Geological time line with reference to some eucalypts (Mya = million years ago; Kya = thousand years ago)

90 – 65 Mya: Myrtaceae migrate into Australasian region of Gondwana from Antarctica (myrtaceous-like pollen found in sediments of this age from the Antarctic peninsula) 70 Mya Indo-Australian plate collides with the Eurasian plate, Gondwana sheds South America, Africa, New Zealand and India (Argentinian eucalypt fossils indicate a proto-eucalypt had already migrated into the South American part of Gondwana from Antarctica)

Eucalypt lineage diverges early within the subfamily Lepidospermoideae Rapid radiation of myrtaceous genera begins 65 – 55 Mya Earliest fossil record of myrtaceous pollen in Australia and New Zealand 60 Mya Two major lineages – Angophora/Corymbia and Eucalyptus diverge 51.9 Mya Date of macrofossil of Patagonian symphyomyrt eucalypt, Chubut Province, Argentina — affinities to E. brachyandra (currently included in sub-genus Minutifructus with E. deglupta, E. howittiana and E. raveretiana), E. guilfolyei, and E. microcorys 65 – 35 Mya Oldest eucalypt macrofossils from southeast Queensland — affinities to Angophora/Corymbia 40 – 45 Mya Australian plate begins to move northwards 40 Mya Last separation of Australian plate from Antarctica New Guinea begins to form along the northern edge of the Australian plate 45 – 20 Mya Estimated age of subgenus Minutifructus (and probable ancient symphyomyrt ancestor of E. deglupta) 30 - 20 Mya Sclerophyllous eucalypts begin to appear in the fossil record 30 – 13 Mya Sections within subgenus Symphyomyrtus diverge 25 – 10 Mya Diversification within sections of eucalypts coincides with a drier and more seasonal climate on the Australian continent 10 – 5 Mya E. deglupta evolves from a symphyomyrt ancestor after differentiation from other symphyomyrt sub-genera and moves in association with tropical rainforest in the northern parts of New Guinea while the latter is still attached on the northern edge the Australian plate 5 – 2 Mya Fossil pollen records suggest modern eucalypt flora did not become widespread until during this time. Onset of severe aridity occurs on the Australian continent. Rapid uplift of the central New Guinea massif isolates the geologically older E. deglupta on its northern side still associated with rainforest. E. deglupta thus retains some primitive ancestral and rainforest-like characters compared to other eucalypts isolated to the south and evolving in in a drier climate 2.58 Mya Last ice age begins leading to glaciation on the central New Guinea massif 2.6 – 0 Mya Further speciation and diversification of eucalypts in the south in an unstable climate 150 - 30 Kya Sea level dramatically rises and falls, at times up to 200 m lower than today. Tasmania connected to the Australian mainland; existing Bass Straight Islands formed hills in the Bassean Plain. 60 Kya Humans arrive in Australia (possibly earlier) and in New Guinea? 25 Kya The sea level dropped to some 135 m lower than today in another significant fall in sea level between 30 and 15 Kya. Australia and New Guinea were connected in a fused landmass called Sahul. Sahul was still separated from Southeast Asia (called Sunda) by a deep channel in which many small islands developed (collectively called Wallacea), some of which are there today. Wallacea was a natural barrier to plant and land animal migration between Sahul and Sunda for many thousands of years, though when sea levels were low the widths of water gaps were considerably smaller. The Indonesian islands east as far as Borneo and Bali were connected to Sunda. Palawan was also part of Sunda, while the rest of the present day Philippine islands including Mindanao formed one large land mass separated from the continental plates north and south by the Sibutu Passage and Mindoro Strait. Recurring opportunities for E. deglupta to migrate from New Guinea west to Seram and Sulawesi and north to Mindanao on disturbed areas such as recent lava flows and older volcanic soils next to intact rainforest through long-distance seed dispersal aided by volcanic updrafts. 10 - 8 Kya New Guinea disconnects from the Australian mainland

25,000 years ago, the sea level was some 135 m lower than what it is today. Australia and New Guinea were connected in a fused landmass called Sahul. Sahul was still separated from Sunda (Southeast Asia)

Around 9,000 years ago New Guinea was disconnecting from the Australian mainland. (Both illustrations sourced from an animation of Sahul sea levels from 100 Kya to the present day at http://sahultime.monash.edu.au/explore.html (accessed 15 April 2019, but not available in 2021).

The molecular phylogeny with best representation of species of Eucalyptus suggests that large stature species like E. deglupta have evolved at least four times within subgenus Symphyomyrtus (with independent evolution in E. diversicolor, E. deglupta and E. grandis).

The rainbow eucalypt appears to have originated from an ancestral eucalypt stock in the rainforests of Antarctic Gondwana. After the Australian continental plate began its northern migration (see timeline), New Guinea also began to form, initially in two parts, one on the northern rim of the Australian plate (today’s New Guinea mainland), the other part as string of islands off the northeast coast (today the Bismarck Archipelago, including New Britain). Molecular evidence suggests E. deglupta evolved from a symphyomyrt ancestor after differentiation from other sub-genera and moved into tropical rainforest in the northern parts of New Guinea while the latter was still attached on the northern edge the Australian plate. It was carried northwards, riding like a surfer on the northern rim of the Australian plate and staying ahead of the areas increasingly subjected to a drying climate to the south, with the rapid uplift of the central New Guinea massif creating the southern boundary.

Accelerated uplift of the central New Guinea massif isolated E. deglupta on its northern side still associated with rainforest. E. deglupta thus retained some primitive ancestral and rainforest-like characters compared to other eucalypts to the south evolving in in a drier climate. Left in its wake to the south were the progenitors of its related present-day species on the Australian mainland (E. brachyandra in north-eastern Western Australia (Kimberly region) and north-western Northern Territory, E. howittiana in north-eastern Queensland and E. raveretiana in central-eastern Queensland).

The migration of E. deglupta to the west and north of New Guinea probably was assisted by a combination of land bridges among the islands of Wallacea during periods of low sea level, by rafting on continental fragments and by dispersal of the very small winged seeds in volcanic updrafts along the western edge of the Pacific plate with its arc of active volcanoes.

The four present-day disjunct localities in the highlands of New Guinea are probably relictual, having been rapidly uplifted on the northern side of the central cordillera in Plio-Pleistocene times, surviving just below the edge of the ice sheet that formed during the last glacial maximum. E. deglupta occurs at about 2,000 metres elevation in the western highlands of Papua near Lake Paniai — this location is less than 200 km west of the receding remnant ice-age glaciers that still exist today in the mountainous region surrounding Puncak Jaya (4,884 m elevation). The morphology of the present-day highland occurrences is somewhat different to the others having wider leaves with less pronounced drip tips (more like the variety schlechteri suggested elsewhere), larger fruits with the valves not prominently exsert, ovary

inferior, not half inferior and number of valves four and occasionally five or six compared with the usual three or four, possibly indicating some change in the direction of evolution in response to a cooler, drier, montane environment. The species is now extinct in the total geographic range of all other extant eucalypts and is not found in the rainforests of the small remaining humid tropical area in northeast Queensland or in rainforests south of the central massif in New Guinea. The isolated northerly mainland New Guinea occurrences of E. deglupta in some places almost abut, but do not overlap anywhere, the southerly mainland New Guinea occurrences of all the other extra-Australian eucalypts which arrived there in more recent geological time.27

In a collaborative project undertaken by Royal Botanic Gardens Melbourne (RBGM), the University of Melbourne and Bogor Botanic Gardens Indonesia and supervised by Frank Udovicic (RGBM) a team has been undertaking analyses of the DNA of E. deglupta using a number of markers on 75 specimens from across its range. The conclusion so far is that the New Britain samples are quite distinct from the Seram, Sulawesi and Philippine samples and that E. deglupta from Seram, Sulawesi and Philippines will form one major clade and the New Britain samples will form a separate major clade.

ITS and ETS sequences have been generated from the same 75 specimens for phylogenetic analysis to clarify the position of E. deglupta within Eucalyptus. The team has been assembling alignments for the sequence markers and incorporating microsatellite data.

Publication of this work was originally expected towards the end of 201928 but is still awaited (October 2022).

27 Carr S G M 1972 Problems of the geography of tropical eucalypts. In Bridge and barrier: the natural and cultural history of Torres Strait. Walker D (ed.) ANU Publication no. BG/3, pp 153-181. Australian National University, Canberra; Payne K G, Dvorak W S and Myburg A 2007 Chloroplast DNA phylogeography reveals the island colonization route of Eucalyptus urophylla (Myrtaceae). Australian Journal of Botany 55:673-683. 28 Frank Udovicic personal communication June 2019.

Eucalyptus deglupta plantations, Open Bay, New Britain, 2018. (© 2018, 2019 Google LLC, used with permission.)

Keravat township, “our” house is still there (near tip of arrow) 50 years after we lived in it, but the old forestry office, forest nursery and 1948 kamarere plantation that was behind the house are of course all long gone.

Keravat River

Keravat 2019. Forestry plantation and silvicultural activities by the PNG Forest Department ceased in 1973, after which the area west of the Keravat River and either side of the Kalabus Road that used to be teak and kamarere plantations has been planted up with oil palm. (Base image: 2019 Google LLC, used with permission. Annotations by J Davidson 2020)

Kalabus

ABBREVIATIONS AND ACRONYMS

A/OIC Acting Officer-in-Charge ACIAR Australian Council for International Agricultural Research (includes Forestry) AFC Australian Forestry Council ANU Australian National University APM Australian Pulp and Paper Manufacturers Appita Technical Association of the Australian and New Zealand Pulp and Paper Industry Inc. C Centigrade CERES Controlled Environment RESearch CFI Commonwealth Forestry Institute (Oxford) cm(s) Centimeter(s) cm2 Square centimetre(s) CSIRO Commonwealth Scientific and Industrial Research Organization (Australia) CTFT Centre Technique Forestier Tropicale (France and Congo) D Diameter DBH Diameter (of a tree) at Breast Height (or 1.3 metres) DNA Deoxyribonucleic Acid DOE Department of Energy (USA) Dr Doctor EAPI Environment and Policy Institute (of the EWC) EWC East-West Centre (Honolulu) FA Factor analysis FAO Food and Agriculture Organisation of the United Nations FCNSWForest Commission of NSW FRI Forest Research Institute (Canberra Australia or Lae PNG) FSC Forest Stewardship Council H Height ha hectare(s) HPH Hak Pengus Hutan (Timber Concession, Indonesian) HQ Headquarters IBRD International Bank for Reconstruction and Development IDA International Development Agency (of the World Bank) IPEF (Instituto de Pesquisas e Estudos Florestais [Forest Science and Research Institute] ITCI Industrial Timber Corporation of Indonesia

ITS Internal Transcribed Spacer IUFRO International Union of Forest Research Organizations JANT Japan New Guinea Timbers JGI Joint Genome Institute (of the DOE) kg Kilogram LA Logging Area LAES Lowlands Agriculture Experiment Station M Metre MAI Mean Annual Increment mm Millimetre m3 Cubic metre(s) Mya Million years ago Myr Million years NCBI National Centre for Biotechnology Information (Bethesda, Maryland, USA) NSSC Neutral sulphite semichemical (wood pulp) NSW New South Wales OBT Open Bay Timber (limited) OIC Officer-in-Charge PCA Principal component analysis PhD Doctor of Philosophy Degree PICOP Paper Industries Corporation of the Philippines PNG Papua New Guinea PNGUT The Papua New Guinea University of Technology Prof Professor RAAF Royal Australian Air Force RFO Regional Forest Officer RGBM Royal Botanic Gardens Melbourne RH Rijks Herbarium RWG Research Working Group (of the AFC) SADF South African Department of Forestry SE Southeast TAA Trans Australia Airlines TRP Timber Rights Purchase UK United Kingdom UNDP United Nations Development Programme

USA United States of America V Volume v/v Volume to Volume WA Western Australia WGD Whole-genome duplication WW I World War One WW II World War Two yr Year ♀ Female ♂ Male