D.J. Boland1, J. Davidson2 and N. Howcroft3
1 Division of Forest Research, CSIRO, P.O. Box 4008, Canberra, A.C.T. 2600.
2 Department of Forestry, Papua New Guinea University of Technology, P.O. Box 793, Lae, Papua New Guinea.
3 Forest Research Station, Department of Forests Papua New Guinea, P.O. Box 134, Bulolo, Papua New Guinea.
The impetus for provenance seed collections of Eucalyptus deglupta Blume and Araucaria cunninghamii Lambert to be made in Irian Jaya, Indonesia, arose from a combined meeting of IUFRO working parties S2.02.8 (Tropical species and provenances) and S2.03.1 (Breeding tropical and sub-tropical species) held in Nairobi, Kenya, October 1973. The importance of both species for tropical and sub-tropical plantation forestry was acknowledged and the need to increase the range of provenance material available for testing was recognised. A case for conservation of some E. deglupta populations has previously been discussed by Davidson (1973).
Until 1975 no provenance seed collections had been made of E. deglupta in Ceram or Irian Jaya or of A. cunninghamii in Irian Jaya. Some time after the Nairobi meeting, it was agreed that Centre Technique Forestier Tropical (C.T.F.T.) would make collections of E. deglupta in Ceram and in Sulawesi, where previous collections had been small and that a collection team co-ordinated from the Forest Research Institute (F.R.I.) Canberra would make collections in Irian Jaya.
The distribution of E. deglupta has been broadly mapped (Davidson 1973, Turnbull 1974) although its distribution in Irian Jaya is less well-known, largely because of the inaccessibility of much of the country's interior. A population of E. deglupta was reported in 1960 near Enarotali (Zieck unpublished) and another population was found in 1961 near the head-waters of the Andjai and Wekari Rivers close to Mt. Netotti (Zieck pers. comm.). The closest airstrip to this locality is near Andjai in the Kebar valley.
There are two species of Araucaria in Papua New Guinea (P.N.G.) viz. A. hunsteinii K. Schumann and A. cunninghamii Lambert but only the latter species is known to extend to Irian Jaya (Gray 1973). The distribution of A. cunninghamii in P.N.G. has been well documented (Gray 1973). The species extends discontinuously from near Milne Bay in the south to near Wutung in the north, which is located in Papua New Guinea near the border with Irian Jaya. The distribution of A. cunninghamii in Irian Jaya is known mainly through unpublished reports, e.g. Zieck.
ORGANIZATION AND TIMING OF COLLECTIONS
The collection party consisted of Mr. D. Boland, F.R.I. Canberra, Australia; Dr. J. Davidson and Mr. N. Howcroft, Department of Forests, Bulolo, P.N.G., Mr. J. Dali, Forest Research Institute, Bogor and Mr. S. Hutagaol, Department of Forestry, Jayapura, Indonesia. Airfares and travelling allowances for party members were paid for from an FAO fund for seed collection granted to F.R.I. Canberra. It was previously agreed that half of all seed collected would be divided between the Indonesian and the Papua New Guinea - Australian participants.
An unsuccessful attempt was made to determine the precise time to make collections before departure. For this reason the timing of E. deglupta collections was deduced from known collection times in Papua New Guinea. The best time to collect Araucaria seed was difficult to extrapolate from Papua New Guinea stands as collection times for stands in Papua New Guinea appear to vary with altitude, latitude and longitude (Howcroft unpublished data).
The collection team met in Jayapura on the 3 June 1975 and then divided into two groups at Biak. Boland, Davidson and Dali went to Enarotali via Nabire to make collections of E. deglupta and Howcroft and Hutagoal to Manokwari with the object of proceeding into the Kebar area to make collections of E. deglupta and A. cunninghamii. Because of unforeseen transport difficulties, the latter party was unable to proceed to the Kebar valley. The Arfak Range was therefore selected as an alternative site in which to collect A. cunninghamii. Travel to all centres was by Merpati, the main commercial airline company in Irian Jaya (main travel routes are indicated in Figure 4).
EUCALYPTUS DEGLUPTA COLLECTIONS NEAR ENAROTALI
Nine luggage carriers were hired at Enarotali. The forester at Enarotali and two members of the local police accompanied the collection team. An outboard motor-boat was hired from the local Catholic Mission to transport the party from Enarotali to Little Kebo (Figure 1). The party walked from Little Kebo to Giteuto where a base camp was set up on the banks of the Kubejo River. Two tree climbers from Kebo joined the collection team.
Four patrols were made from Giteuto to inspect E. deglupta (“djewo”) seed crops (Figure 1). The first was made to the steep hillsides immediately north-east of the base camp. The second was made to the west banks and adjacent hillsides of the Kubejo River. The third patrol was made into the headwaters of the Kubejo River from where an unsuccessful attempt was made to venture into the Erome River valley. The fourth patrol was made to Kederebutu.
In the Kubejo River valley E. deglupta usually occurred as scattered veteran individuals or sometimes in small clumps of up to seven trees. One large stand of about 20 trees was observed in a gully behind a ridge on the eastern side of a tributary of the Kubejo River, known locally as Gummi River. Very few trees were seen in riverain positions and most were situated high up on the steep hillsides and on ridges. Several E. deglupta stumps and logs from recently felled trees were seen. The survival of the remaining trees is probably associated with their position in being difficult for the villagers to fell and extract. It was estimated that 400 trees were seen. Regeneration was extremely poor. The main associate species were Castanopsis, Myristica and Eugenia spp.
The soils around the Wissel Lakes are derived mostly from limestone parent material. In the Kubejo River valley and near Little Kebo, the soils are derived from sandstone and siltstone parent materials. E. deglupta was found growing on these latter soils only. Between Kebo and Little Kebo there is a small area of soils apparently volcanic in origin. The altitudinal range of the species is approximately 1 700–2 000 m. Rainfall averages 2 500–3 500 mm per annum. Because of altitude the nights are very cool.
Herbarium specimens were collected from eight trees and some wood samples were taken. The seed crop was generally poor with approximately 160 g of seed collected from four trees. Two collections were made by tree felling but most were made by climbing. The climbers used a technique of climbing a nearby smaller tree then crossing over to the collection tree, bypassing the slippery, broad part of the trunk. Sometimes a vine bridge would be made between the two trees. A vine loop was also placed between the climbers ankles for support while climbing. Seed bearing branches were severed by machete.
E. deglupta is one of the most difficult eucalypt species from which to collect seed. The collection period is short because mature seed only remains on individual trees for a few weeks before dehiscence commences. Several trees were carrying dried, open fruits. While the visit did not coincide with the peak period of seed production (which seemed to be 1–2 months earlier) there were many individual trees with inflorescences at widely different stages of development. This suggests that the period in which seed can be collected is lengthened although the number of individuals from which seed can be collected outside of the peak period is lessened. Collection by whole tree felling is unsatisfactory because fruits scatter when the crown hits the ground. Good aeration of the fruits after collection is also essential in humid conditions to avoid seed deterioration through fungal growth.
The maximum size of trees was 60–65 m in height and 160–200 cm diameter. They were smaller in size than large veterans encountered by one of us (J.D.) in New Britain. Logs were sound to their centres (Photograph 1) with some evidence of ‘punky heart’ and incipient decay. This is in marked contrast to veterans in New Britain which have very large pipes and only 20–30 cm of solid wood on the outside.
The shape of trunks of E. deglupta trees was usually straight or slightly twisted and buttress roots were observed. The base of the trunk was often very enlarged and knotty; a feature that is not common elsewhere.
Crowns of E. deglupta were large with heavy branches which were considerably enlarged at the junction with the trunk (Photograph 2). As the crowns of adult trees emerge 10–15 m above the surrounding canopy, it is possible to recognise the species from a great distance on land and also from the air because of its characteristic crown shape, branching habit, open foliage and light coloured leaves.
The timber of E. deglupta is prized by the local villagers for several uses. The most important use is for the building of canoes. These are blunt-ended and hewn from solid trunks up to 1 m in diameter (Photograph 3). No outrigging is attached for stability. It was estimated that there would have been some 200 canoes in the area although not all were of E. deglupta. The species is also in demand for pig-fence stakes (Photograph 4), bridges over small streams and firewood. The bark of E. deglupta is sometimes used as a roofing material.
E. deglupta fruits from near the Wissel Lakes are morphologically different from other known provenances. They are larger and the fruit valves are not prominently exsert (Figure 2). The ovary is inferior and not half-inferior as is the general case for E. deglupta. The number of valves per fruit is mostly four, but occasionally five and six - other provenances usually have three or four valves. The staminal ring is sometimes deciduous, but this is not uncommon in E. deglupta.
The shape of adult leaves from the Wissel Lakes area is also different from other provenances. Leaves are from 5 to 11 cm (average 8 cm) in length and from 3 to 7.5 cm (average 4.5 cm) in width. The basal angle of the leaf lamina is markedly obtuse. The shape and size is similar to the Waria River (P.N.G.) provenance (type locality of E. schlechteri Diels) and very different from Philippines and New Britain (P.N.G.) specimens which have longer, narrower leaves with pronounced drip tips.
Upon return to Enarotali a short patrol was made to Lake Tage in search of Araucaria but only a small area of Podocarpus regeneration was seen. During this patrol unconfirmed reports were received from villagers that E. deglupta also occurs in the Pugo River valley south of Enarotali and in the Koto River valley near Obano (Figure 1).
E. deglupta has been cultivated to a small extent in Irian Jaya. A few street trees were observed at Enarotali. A small stand was also inspected in the Tafel Berg plantation near Manokwari. The source of the trees at Enarotali is most likely to have been the Gazelle Peninsula, New Britain (P.N.G.) and the introduction took place around 1957 (Zieck pers. comm.). The origin of the plantations near Manokwari is less well known although from examination of trees there it was considered that some blocks were of New Britain origin while others were of Vogelkop, Irian Jaya, origin.
There is a strong need for gene conservation of the Wissel Lakes population of E. deglupta. The population is morphologically distinct. The number of trees seen were few. Regeneration was very poor. The overall impression is that the few remaining trees will soon disappear.
ARAUCARIA CUNNINGHAMII COLLECTIONS IN THE ARFAK RANGE
Messrs. Howcroft and Hutagaol travelled by outboard motor prau from Manokwari to Maroeni and then hired a truck to get to the first base camp. Accompanying the collection party were five forestry personnel from Manokwari and four carriers from Maroeni village. The route taken to get to the stands is indicated in Figure 3.
The Araucaria population was located above 790 m. The approximate distribution of the stand is shown in Figure 3. Stand density was 8–16 stems per hectare. Trees were located in small clumps of 3–4 trees. The stand was associated with a dense understorey of rainforest species. The larger trees in the stand seemed even-aged and generally did not appear to be as tall as those in Papua New Guinea. Tree heights of the tallest trees ranged from 50 to 55 m with diameters from 70 to 90 cm. Regeneration was sparse and soils were dark-to light-brown clay loams.
Tree crowns in the Arfak Range were broad spired and in many cases were flat on top. The short internodes near the top of the crown suggested senescence. In the middle of the crown the internodal lengths were fairly regular. The lower bark was red-brown in colour, generally loose, being papery to stringy in texture. The surface of the upper bark was mostly smooth and white to red in colour. The local name for the species was ‘alloa’.
Several trees were climbed using safety belts and climbing irons and herbarium specimens, a small quantity of seed and some wood samples were collected. Cones were generally overmature and fragmented when touched. There was a heavy ripe male flower crop with some shed amenta lying on the ground. While the prospect for a seed crop in 1976 was poor, the crop of 1977 looked promising. Suggested collection time would be April–May.
Cultivated trees of A. cunninghamii were observed in three areas. A line of trees was observed in front of Sentani airport and the seed source for these is reputed to be the Cycloops Mountain (Zieck pers. comm.). Five hectares of a 15-year old plantation was observed on Biak and another stand was seen at the Amban Forestry and Agricultural Research Station near Manokwari. Both stands were reputed to be of Kebar origin.
There were several specimens of Araucaria in the herbarium at Manokwari. Some were from Kebar and one was from the eastern side of the most easterly of the Anggi Lakes. This area is the type locality for A. becarrii Warb. (Womersley pers. comm.) which in the past has been believed to be a synonym of A. cunninghamii. The cone core (1 only) on this specimen had a very broad base and was top-shaped in appearance being quite unlike other known cone cores of A. cunninghamii in Irian Jaya and Papua New Guinea. The leaves were coarse to touch.
A tentative map of the distribution of A. cunninghamii in Irian Jaya is given in Figure 1. A. cunninghamii was observed by our party on the Cycloops Mountains from Sentani airport and other stands were seen from the air on Japen Island (occurrence confirmed by Verboon pers. comm.) and on ridge tops in the Utawa and Bumi catchment areas near Nabire. Araucaria is also reported to occur south-east from Babo between the headwaters of the Sjuga-Wasura River from near sea level to 500 m.a.s.l. on acidic sandy soils (Sosrodihardjo and Zieck pers. comm.), near Sausapor (Zieck pers. comm.), north-east of Enarotali (Zieck pers. comm.), at Mabilabol in the Sibil River valley (Brongersma and Venema 1962) and near Fakfak (Zieck pers. comm.) where it is reported to occur on soils derived from limestone and sandstone. The approximate locations of other populations are shown in Figure 4 (information from Zieck pers. comm.).
Some visual differences were observed between provenances in Papua New Guinea and Irian Jaya. The differences are in leaf texture, crown shape and branch internode patterns but it is emphasised that the overall importance of these characters has not been rigorously examined. Arfak seedlings had finer, softer juvenile foliage compared with provenances from Bulolo, Finisterre Ranges and the Eastern Highlands region of P.N.G. but were perhaps slightly coarser than seedlings from the Southern Highlands of P.N.G. Trees observed both in cultivation and in situ in Irian Jaya displayed a rather uniform branching pattern with regular internodal lengths. Tree crowns were in general broader-spired than those in P.N.G.
The collecting teams re-grouped in Biak and all material collected was divided two ways. Unfortunately the viability of seed taken into P.N.G. was extremely low apparently because of zealous treatment with methyl bromide fumigation. Seed taken from Biak to Bogor is believed to be viable.
Before returning to Australia one of us (D.B.) collected herbarium and seed material from Eucalyptus species in the Port Moresby region. Species collected were E. confertiflora F. Muell., E. alba Reinw. ex Blume, E. tereticornis Sm, E. papuana and E. aff. confertiflora from near Kupiano.
We wish to make special mention of the Indonesian counterparts, Mr. Junus Dali and Mr. Sahil Hutagaol, for the particularly valuable assistance rendered as language interpreters and protocol advisers. The good co-operation between the forestry officials of Irian Jaya in Jayapura, Biak, Nabire, Enarotali and Manokwari and the collection party was greatly appreciated.
For information on occurrence of E. deglupta and A. cunninghamii in Irian Jaya, we would like to thank Mr. L. Verboon and Mr. S. Sosrodihardjo of the Department of Forestry, Irian Jaya, Indonesia; and Mr. J. Zieck, Department of Forests, Papua New Guinea.
We also wish to acknowledge the assistance of Mrs. M. Risby and Mr. G. Moss with the illustrations and Mr. J. Evans for the photography.
Brongersma, L.D. and Venema, G.F. 1962 “To the Mountains of the Stars”. (Hodder and Stoughton : London).
Davidson, J. 1973 Conservation of the gene resources of tropical Eucalyptus deglupta Blume. Trop. For. Res. Note S.R. 12, Dept. of For., P.N.G.
Gray, B. 1973 Distribution of Araucaria in Papua New Guinea. Res. Bull. No. 1, Dept. of For., P.N.G.
Turnbull, J.W. 1974 Kamarere Eucalyptus deglupta Blume. Forest Tree Series, No. 175, For. Timb. Bur., A.G.P.S.
Zieck, J.F.V. 1960 Eucalyptus deglupta in Nederlands New Guinea. Unpublished Forest Report G.B. 1942, 1 June 1960.
FIGURE 1 - Route of journey from Enarotali to inspect stands of Eucalyptus deglupta.
FIGURE 2 - Provenance variation in Eucalyptus deglupta fruit shape
L.H.S. Typical fruit from near the Wissel Lakes, Irian Jaya, Indonesia.
R.H.S. Typical fruit from near Keravat, New Britain, Papua New Guinea. (Scale approximately × 7)
FIGURE 3 - Trip route from Manokwari to the Araucaria cunninghamii stands in the Arfak Ranges.
FIGURE 4 - Known areas of Araucaria cunninghamii distribution in Irian Jaya, Indonesia (main air routes travelled are indicated by broken lines).
PHOTOGRAPH 1 - Eucalyptus deglupta tree stump indicating sound timber to tree centre.
PHOTOGRAPH 2 - Crown of Eucalyptus deglupta
PHOTOGRAPH 3 - Canoe on the Wissel Lakes similar to those made from Eucalyptus deglupta logs.
PHOTOGRAPH 4 - Felled Eucalyptus deglupta tree with villagers commencing to cut up the log for several uses, including stakes for pig fences.