Introduction

Rapid deforestation in the tropical regions at present has been bringing about not only the fast decling in forest resources but also environmental destruction, decrease in biological diversity, the worsening of socio-economic conditions. To stabilize and furthermore to improve the present situation in forest resources, every effort should be made to establish sustained and proper systems for holding a balanced relationship between forest management and timber utilization.
From the stand point of timber utilization, it should be stressed that basically there is no single species destined for waste and that every species can be precious material for the world present and future. Nevertheless, there has been enormous amount of wood left untouched or burnt after the logging and also not necessarily converted efficiently by the industry. Moreover, it should not be ignored the existence of a great many non-commercial species which have been evaluated unreasonably lower than their real value on the market and they are eventually named lesser-known species, being destined for lower-graded uses. This is mainly because of the reason that they have not been studied enough be the industry for the effective utilization as they do not provide sufficient volume by species for mass-production regardless of their quality.
One of the most urgent and essential tasks of wood technology at present for the contribution to the sustaining tropical forest resources is the efficient and intensive utilization of commercial species and also maximizing the effective utilization of these lesser-known species.
It was the early 1960s when signs of the influx of the tropical Asian timbers began to appear on the market. To meet the demand for information about the characteristics of the tropical Asian timber species not only of consumer but also of industry, Wood Technology and Wood Chemistry Division of Government Forest Experiment Station (current Forestry and Forest Products Research Institute) have conducted a series of joint research projects. Anticipating the outcome brought about be the drastic exploitation of the forest resources in the tropical Asian regions, particularly of dipterocarp species, member became aware of necessity of information about the non-commercial spices, later internationally known lesser-known species, for their effective utilization.
Following sporadic projects, the full scale joint project started in 1964 with the Cambodian species of which sample logs with herbarium materials were collected in forests with the hearty cooperation of Cambodian Forest Department and Forest Research Institute.
After the conclusion of the project for Cambodian timber species, studies on the species of Dipterocarpaceae, Lauans, Apitong etc. from the Philippines, followed by Meranties, Keruing etc. from Sabah and Sarawak, of Malaysia and Kalimantan of Indonesia, have been made using commercial logs from the reliable sources after the identification based on wood anatomy. Together with these dipterocarp species which are considered to be standard or traditional commercial woods, various non-commercial species which have been handled in bulk on the Japanese market have been studied.
To meet the future changes in species component caused by possible shift in the region of forest developments, at the later phase of the series, the emphasis of the research was placed on non-dipterocarp species and thus the sampling location was shifted to the Pacific regions, Papua New Guinea, Solomon Islands and non-tropical New Zealand. At the end of this phase, the number of samples examined was 67 from 47 genera of 27 families.
At the final phase of the series, under the financial support of Science and Technology Agency of the Government, a large scale project started to study Papua New Guinean timber species which are mainly lesser-known on the market. For collecting sample logs with herbarium vouchers, a party of research staffs was dispatched to East New Britain in 1975 and then to West New Britain in 1976. The total number of the samples from natural forests of these two districts was 89 form 58 species and 4 samples from 3 species from plantations. They covered almost all the commercial species on the market at the time and also the large part of so-called minor species in Papua New Guinea. Of them, 50 samples from 42 species which were sufficiently sized for solid wood products were examined by species and the results were included in this data base. Because of the size, other 39 samples from 30 species were exclusively studied in a mixture to examine their suitability for pulp and board making and the results were not includ ed in this data base. It should be noted that enormous assistance have cordially been given by Forest Products Research Center, Boroko and Herbarium, Lae, Papua New Guinea for sampling operations and their identification.
The data from these investigations have been published in a series of 21 reports with the title of "the Properties of Tropical Woods" in Bulletin of Government Forest Experiment Station between 1966 and 1978. They were followed by a series of 10 reports with title of "Properties of Some Papua New Guinea Woods Relating with Manufacturing Process" published in the same Bulletin (renamed Bulletin of the Forestry and Forest Products Research Institute 1978) between 1977 and 1980. However, data may not have necessarily been accessible to foreign readers, because they were published in Japanese with English summary. Consequently, the dissemination of the information has likely been limited in a narrow circle.
The purpose of this paper is to present the previously published information compiled from the above-mentioned reports in a form of data base particularly for foreign readers. This data base will provide a useful means for the effective utilization of timbers in the tropical Asian and the Pacific regions where information on timber properties and their utilization is not sufficient. It may also facilitate to select species for further studies or to plan an additional investigation when much more information is necessary.