EXPLORATION AND PROVENANCE SEED COLLECTIONS IN PAPUA NEW GUINEA 1976/77: ARAUCARIA CUNNINGHAMII LAMB. AND ARAUCARIA HUNSTEINII K. SCHUM.

by

N.H.S. Howcroft
Forest Research Station
P.O. Box 134
Bulolo, Morobe Province
Papua New Guinea

INTRODUCTION

The following report covers exploration, seed collection activities and results from August 1976 to December 1977, in accordance with the agreements arranged between the Department of Primary Industry, Office of Forests (formerly Dept of Forests), Papua New Guinea and FAO and UNEP in 1976.

BACKGROUND INFORMATION

Initial Exploration/Collections

Exploration and collecting started in 1972. By the end of 1975, a total of 12 A. cunninghamii and 5 A. hunsteinii stands had been explored and seed from a number of provenances collected.

One new variety of A. hunsteinii was discovered; this is believed to be the original A. klinkii Laut. It is a glaucous variety and several stands are known to exist towards the south-east of Papua New Guinea mainland, including Agaun in the Milne Bay Province. In addition to this, another previously unknown provenance of this species was located at Erave in the Southern Highlands Province.

Apart from noting the differences among the A. hunsteinii provenances in the field, differences were noted among a number of provenances of A. cunninghamii, particularly in the juvenile foliage of seedlings and to a lesser extent in adult crown, form and bark characters. Some data from a provenance trial in the Bulolo Research nursery is available to support field observations on seedling foliage differences.

Timing of Seed Collections

Except for areas in which collections have been made in the past years, the seed collection times for many areas are not well known, and local knowledge in most cases is either poor or non-existent.

Generally speaking, most A. hunsteinii populations appear to bear ripe cones between August and September with an overlap into October in some areas; A. cunninghamii on the other hand is much more variable. This appears to be partly due to its wider distribution range which covers a larger variation in locality types and climatic conditions. So far nothing has been determined on the time of seed collections for stands occurring close to the Northern Coastline, with the exception of the Fergusson Islands Mt. Morima stand, nor is anything known about the highest elevated stands on Mt. Dayman and Mt. Suckling.

Most collections to date have been conducted between August and September; Fergusson Island collections have been made in November.

Seed collection periods of costal stands are likely to occur between November and the following March or April.

Collection Methods

In all instances trees were climbed to remove cone crops. This was done by a labourer skilled in the use of climbing irons and with experience in Araucaria seed collection work. No trees were cut down for the collection of cones.

Because of the great expense involved in exploration of stands, and the number of instances where seed crops were absent or had been missed, the practice of collecting live seedlings over a broad area of each stand was adopted to provide material to establish conservation stands ex situ. Seedling samples were usually taken from around specific trees and the batches coded to keep a record of the range of sampling.

Organization of Exploration/Collecting

Past and present exploration and seed collecting has been carried out principally by Mr. N.H.S. Howcroft with the assistance of a specialist/labourer skilled in climbing. In the 1976–1977 period, additional assistance was obtained from staff in several provinces to collect seedlings and/or seed where available, and to assess the presence of cone crops in areas where previous attempts at collection had failed. This enabled the principal collecting team to cover new areas for exploration and seed collections. In all stands visited, the traditional owner of the trees, clan leaders, village elders and villagers were consulted for permission to enter and collect in the stands.

Villagers were employed by the collecting team to assist in bagging and carrying cones selected as well as assisting in carrying camping gear. Cones and seedlings were paid for. The money was usually given to the traditional owner of the trees or to the village leaders. These payments were made from an advance drawn from the government.

FIELD WORK

Selection of Collection Zones

The collections made in 1976 and 1977 were aimed at sampling the extreme ends of the distribution range of A. cunninghamii in Papua New Guinea, as well as covering a number of stands in between. One Araucaria hunsteinii stand visited had been previously collected from, but seed collections had been poor. Two other stands had been previously explored. In all, a total of five A. cunninghamii and three A. hunsteinii stands were visited for seed collections. These are listed in Table 1, and the localities are shown on Maps 1 and 2.

A Brief Description of Stands

(a) Erave - A. cunninghamii (Map 1 - Locality No. 24)

An unusual stand of about 1 000 ha; rather dense in parts; on ridges and on extremely swampy sites. The general form of trees is good. Portions of the stand are in poor health which may be partly due to extremely wet seasonal conditions of sites. Small quantities have been logged by the missions. The juvenile foliage of seedlings in this stand is extremely fine and soft, unlike that of the Morobe, Western and Eastern Highlands provenances which are coarse. Generally, the Erave provenance is similar in this respect to other Southern Highlands provenances such as Pimaga and Lake Kutubu. Regeneration is reasonably good in the area.

(b) Wutung - A. cunninghamii (Map 1 - Locality No.33)

This is a small stand of approximately 100 trees. The stem form is sinuous in many cases; many of the trees are not very large, and spaced well apart. The bark of the trees appears to be coarser than that in many other stands examined. Regeneration is not as plentiful as in the Erave stand. Seedlings have a slightly coarse type of foliage but this trait is not as pronounced as in the Western and Eastern Highlands provenances. The nearest stand is in the Cycloop Mts. near Djayapura, several miles away across the border of Irian Jaya. There appears to be some similarities in bark, foliage and branching between this species grown at Sentani (ex Cycloops) and the Wutung trees. The Wutung trees do not appear to be vigorous.

(c) Woitape - A. cunninghamii (Map 1 - Locality No.8)

The stands are rather scattered and depleted by gardening in the Woitape area. Many of the large trees appear to be in poor health, judging by the state of the upper crowns. No distinguishing features other than coarse branching were noted in this population.

Stem form is variable; sweeps were often seen. Mature trees are more common in this area than in the Erave and Wutung stands and often much taller. Natural regeneration is extremely variable and often very poor; seedling foliage is rather coarse. The overall impression of the stands in this area is that they are senescent and deteriorating, and that ex situ conservation stands are needed for this provenance.

(d) Okasa - A. cunninghamii (Map 1 - Locality No.16)

Located on the Lamari River, this large stand covers an area of approximately 1 000 ha. To date it has not been logged and is almost untouched by gardening. The trees are very large with reasonably good form occasionally marred by sweeps and double leaders. The area has been used as a source of seed for many years, and is representated in North Queensland, Australia by a block planting. Regeneration is sparse but adequate. Seedling foliage is coarse. Generally the stand is healthy and does not appear to be threatened in any way.

(e) Fergusson Island - A. cunninghamii (Map 1 - Locality No.1)

There are two stands on this island and they are somewhat unique to Papua New Guinea being the only stands to be found on an island off the Papua New Guinea mainland, although a stand also occurs on Japan Island in Irian Jaya.

The Mt. Morima stand near the village of Ailuluai was chosen for exploration because of easy access. This stand contains some 80 trees mostly well spread out near the crest of the mountain and on the north western slopes. A larger group of trees was noted on a range to the west of the area and examined. The trees are generally shorter than the mainland provenances, and their taper is pronounced. The branching habit is variable, although regular short internodes appear to be most common. Branches are often rather small in relation to bole diameters and regularly horizontal. Clear bole lengths are relatively short and stem form is often marred by sweeps which, judging by their direction, could have easily been produced by strong winds. The foliage of adult trees appears to be slightly glaucous, and certainly this appears to be so for a number of 5 year old trees growing in Ailuluai village. The bark is distincly tighter, less stringy and redder than that of the mainland provenances. The foliage of seedlings is not very coarse. Older regeneration is scarce although recent regeneration, about 1 to 2 years old, is fairly plentiful in parts of the stand.

The stand does not appear to be reproducing itself very well and this could be due to cockatoo damage to seeds, and to the removal of immature cones by gale force winds.

(f) Erave - A. hunsteinii (Map 2 - Locality No.15)

A small stand located close to Mt. Matmuri 2½ hours walk from Erave. Some 50 trees were counted in this stand. In parts, the trees are spread out suggesting that sections may have been destroyed by gardens. The trees are of the normal green variety. Stem form appears to be good and generally there appears to be nothing to distinguish it from the Morobe Province stands. Regeneration appears to be rather poor in the sections examined. Gardening and grass fires are likely to decimate portions of the stand in years to come.

(g) Jimi - A. hunsteinii (Map 2 - Locality No.17)

The main Jimi Valley stand is reported to be about the third largest in area in Papua New Guinea. The trees are not, however, as dense in this area as was the case for the Bulolo stands in the Morobe Province which have now been heavily cut. There are also a number of small scattered outlying stands within this area. The trees generally do not appear to be very different from other green leaf varieties; the bark may be slightly coarser and sheds in relatively large plates; the branching is more candelabra-like, and the foliage a little lusher. Regeneration is rather sparse in the areas visited, and the small outlying stands in the area are situated so that fires from gardening could very easily decimate them. New roads are proposed for this area and there is a high likelihood of the stands being milled sometime in the future.

(h) Pindiu - A. hunsteinii (Map 2 - Locality No.10)

This very small stand of about 20 hectares in area is located about 3 kilometers from Pindiu airstrip. It is unusual in that it is very isolated and it is thought that this is the stand where the type specimen A. schummaniana Warburg originated.

The trees are generally much shorter than those found in other A. hunsteinii stands. The only other difference noted was that the bark is not as coarse as in other provenances, but pustular, and smooth in-between. Regeneration appears to be very good.

The area of the stand has been reduced by several hectares through logging to supply timber for the patrol post, and a number of trees have been destroyed by constant tapping for resin which is used to fasten arrow heads to shafts. The stand is subject to further destruction. Seed fall seems to occur much later than in other stands (October – November); however, further observations are needed, as 1977 when the stand was visited, could have been an unusual year in this respect.

Results of Seed and Seedling Collections 1976/77

Seed weights, and numbers of seedlings secured for ex situ conservation stands for the 1976/77 collections are listed in Table 1.

Successful seed collections at Wutung continue to evade us and seed fall time has still not been determined.

A total of 268 kg of A. cunninghamii seed and 41 kg of A. hunsteinii seed was collected in 1976/77 (Table 1). Wild seedling numbers per provenance (Table 1) are small in some instances but will be added to from seedlings raised from seed collections (or from other seedlings) collected in previous years.

Table 1. FAO Seed Collections and Reconnaissance in Papua New Guinea 1976–1977

 * A. cunninghamii
** A. hunsteinii

MAP 1.

* Gray, B. (1974). Distribution of Araucaria in Papua New Guinea. PNG For. Dept.For.Res.Bull. 10.1

MAP 2.

X - KNOWN LOCALITIES OF THE GLAUCOUS VARIETY