报告摘要：Wood is remained a primary construction materials in thousands years because there is no competitive material has all the advantages of wood. One may equal in stiffness but lack its insulating quality and another may rival in strength but fail to measure up in ruggedness. Artifacts in Indonesia showed the use of wood in religious building, public building, and housing as well as in furniture, handicraft and daily equipments since the Hindu and Buddhist Era. The acculturation of local values and exterior values in culture affected the design of the artifacts.

The un-valuable culture in using wood for religious life, shelter and daily equipments faces with the fact that supply of wood decreasing yearly so that innovation is necessary to preserve the high value of people culture that has been developed from the ancient era.

A. Wood in Traditional Houses

Although the vernacular architecture of Indonesia encompasses a wide variety of styles and technologies, a number of common themes and principles can be discerned. These correspondences are legacy of a shared Austronesian ancestry. The Austronesian languages group embraces most of island Southeast Asia as well as a part of Vietnam, Taiwan, Micronesia, Polynesia and Madagascar. The Austronesian house typically consists of a rectangular structure, elevated on posts, with a thatched roof. The most suitable material for such architecture is wood.

Piles built of hardwoods like teak (Tectona grandis), cengal (Balanocarpus heimi), ironwood (Eusideroxylon zwageri), may endure for over hundred years, while some palm trunks, especially nibung (Oncosperma tigillarium), also make ecelent, long lasting pile. Easily available and replaceable, bamboo is widely used for ordinary houses or temporary structures. Indigenous Indonesian building are held together entirely without nails, relying instead on a variety of jointing techniques, which are sometimes reinforced by pegging, wedging or binding.

The vernacular architecture Indonesia typically employs a post and beam method of construction. Putting this together is largely a matter of shaping and jointing wooden members with a range of specialized tools which include axes, adzes, and chisels. Rounded logs are squared by splitting or by means of a pit-saw worked by two men. Piles structures, with posts buried in the ground have been mostly superseded by stilt structures where the house posts rest on top of foundation stones, and stability is achieved by horizontal rails running through apertures cut into the posts. An alternative strategy for stabilizing the lower part of a post and beam building is to anchor the posts in a crossed-log foundation. This was common in Sulawesi and North Sumatera. Another method is to add diagonal struts or braces as applied in Nias. The massive foundation posts of the house are braced by equally massive diagonal struts. The latter are probably an adaptive response to earthquake stresses in the region of constant seismic activity.

Sometimes a box-frame is employed for the upper portion of a building. This consists of vertical studs that are slotted into horizontal sills and held together at the top by wall-plates. A variety of jointing techniques maybe used, including mortise, tenon joints, lapped joints and notched joints. Box-frames are often further stabilized by wooden panels that are fitted to the main frame work using tongue and groove, or mortise and tenon joints. The ensemble operates like a load bearing wall, but usually the walls of vernacular structures serve only to provide protection from the elements and secure privacy. As such, they may consist of matting, palm leaves folded round a lath and stitched together with a strip of rattan, flattened or plaited bamboo panels, as well as wooden boards and panels, depending on the use and status of the building.

The typical roofs of Indonesian houses are supported by rafters which are fixed at the ridge and convey the roof loads to wall plates or purlins. Vertical columns, or some other kind of internal framework, may provide additional support and in some cases to prevent a deformation in large structures. The extended roof ridge has been elaborated in a number of different ways throughout the Archipelago. But, not all of Indonesian houses have extended roof ridge although the height of the roof may be still be impressive. Traditional Indonesian houses are almost entirely built of organic materials such as wood, bamboo, palm tree, palm leaves, grass thatch and plant fibers which are deployed in variety of ingenious ways to provide protection against the sun and rain. Wooden roof singles, atap thatch (palm leaves folded round a lath and stitched together with a strip of rattan), grass thatch and bamboo used as roof cover in traditional houses.

B. Wood in Modern Houses

The use of brick in Indonesia was found as a new architectural material in Hindu era, firstly for the temples structures then for houses. The Negarakertagama, a court poem written in 1365, described the house of the palace retainers as having “carved wooden pillars, the basis are bricks, red, fitted with raised work, select, ornamented with figures. Spread, to be sure, the products of the potters, used as roof tops of those houses, superior”. The gradual spread of Islam does not seem to have greatly affected the vernacular architecture of the region and traditional house types conforming to a basic Austronesian morphology continued to coexist alongside new architectural form in much of the Archipelago. During the Dutch occupation, in urban area the houses architecture was developed in three styles namely Dutch style houses, transitional Dutch Indies country houses, and Indies style country houses, which mostly built of bricks and concrete as main structures. The assimilation of Dutch and Indonesian architecture had not changed significantly after independence especially for urban people or the high position person in rural area. As a house carries over a visual symbol of the position of the owner, most of the people throughout the country feel that having modernized Indies style country house more prestigious than traditional house. Masonry houses of bricks or concrete blocks replaced the traditional wooden houses. The developed main structure was reinforced concrete with brick or concrete blocks for wall and wood for roof structures and door/window frames. Unfortunately, such practice has not been applied inappropriate techniques for earthquake hazardous or soft soil area. Many houses seriously damaged due its weight accelerated the earthquake force and the reinforcement of the structures was insufficient.

Nowadays, Indonesia is facing the fact that about 1 million houses should be built annually for supplying the population growth and about 7 million houses as a backlog that the supply should be accelerated. Because wood is still a dominant building material for roof structures and door/window frames, minimally 6 million cubic meters wood in the form of timber should be supplied annually in housing construction activities. Since wood and wood based materials have become an essential commodity for the national income after petroleum, supply of wood from natural forest had decreased significantly. Recently, logging from natural forest had been significantly restricted. This situation affected the supply of wood for housing construction, high quality timber not available in domestic market. Light steel frame, plastic frame and light concrete frame have been introduced to substitute the use of wood in housing construction but it give the impression that the people anxious to use the new materials.

Planted timber estates with fast growing species were developed about two decades ago for supplying wood in pulp and paper industries. With the decreasing of supply of wood from the natural forest, wood from planted timber estate starting come into the housing construction activities. Planners, contractors, developers, and the people are anxious to utilize the wood from fast growing species because the appearance of the wood as low density and low quality timber. The development of appropriate technologies for improving the quality of wood from fast growing species is necessary to improve the service life time of the wood. Base on the social and cultural condition of the people, situation of the wood supply in housing construction activities and the fact that Indonesia is laying on the earthquake hazardous area, light frame timber structure with cement bonded board for the wall and the design which adopted local value and local culture can be developed to accelerate the gap between supply and demand of houses for the people in Indonesia.  
   
C. Wood as handicraft and furniture materials

The first material found as handicraft material was stone. It was used in Javanese temples which expressed complex messages about the divine nature of the structure. The historical evidence showed that since the use of stone replaced by wood and metal, stone work had decreased gradually. The oldest wooden craft was found in Pajajaran Era and Majapahit Era as Hindu and Buddhist Kingdom about 15th Century. In the late 15th Century Islam spread through the Archipelago by assimilation, trade and military conquest and before 17th Century the greater part of the Archipelago came under Muslim control. Artifacts showed the assimilation between Hindu and Muslim can be found in the shed of Sunan Gunung Jati (the Islamic pioneer) in Java Island cemetery in Cirebon West Java which shows the Pajaran wooden motif and the column of Demak Mosque in Central Java which shows the Majapahit wooden motif.

With the Islamic influence; no temples were built; a few artifacts showed the stonework and wooden and metal craft works became popular. The wooden and metal craft industries have developed since the product became ordinary good of the people. Wooden craft mostly found in furniture, building ornaments, daily equipments and decoration, while the metal in weapon namely keris; a wavy double-bladed dagger. The wooden craft ornamentation developed in local area as acculturation of local values and external values which come from another culture. Chinese expedition came to Indonesia since Hindu and Buddhist Era but more intensive in Muslim Era, some Chinese ornament could be distinguished in Indonesian artifacts. Although Dutch people occupied for almost 350 years, a few effect of European culture in Indonesian wooden craft due to the resistance of the people to accept the Dutch. Wooden crafts for furniture, building ornaments and decoration were usually made of high quality wood species such as teak (Tectona grandis), iron wood (Eusideroxylon zwageri), sono keling (Dalbergia latifolia) and cendana (Santalum album) but for daily equipments were made of lower quality wood species such as nangka (Artocarpus heterophylla) and rasamala (Altingia excelsa). 

The need of wooden furniture increasing year by year with the increasing of population growth and people prosperity, high escalation of the need happened when furniture is one of the export goods. On the contrary, supply of high quality timber decreasing with the expansion of human settlements due to the population growth. Cost of raw materials beyond the affordability of artist and producers. One important fact in furniture industry in Indonesia nowadays is the use of acacia mangium as substitute material of teak. Although it is lower in quality but the appearance similar to teak. Acacia mangium is indigenous species of Eastern part of Indonesia, in Papua and Maluku. It was widely planted about two decades ago for supplying pulp and paper industries due to its fast growing and the productivity was reported as 20-50 m3/ha/year. Acacia mangium is a moderate density and strength wood and low moderate durability. Because it was planted for pulp and paper which planted in high density plantation, thinning and pruning rarely applied, knots dominantly found in acacia mangium wood. Innovation in silviculture as well as improving the quality of the wood is necessary to ensure the balance of demand and supply of wood in furniture industry.     
 
References
1.Anonymous. 1986. History of Indonesian Handicraft Industry, Department of Industry (in Indonesian)
2.Tjahjono, G.. 2001. Indonesian Heritage. Architecture. Archipelago Press.
3.Sumartono, A. 1997. Design of Wood Carving in Jepara Province, Middle of Java Province, Indonesia. Master Thesis of University of Indonesia. (in Indonesian)
4.Djojosoebroto, J. 2003. Acacia mangium for wood construction. Proceeding of Available Wood Construction.
5.Firmanti, A. and D. Nandika. 1998. Treat-ability of agathis alba, acacia mangium and paraserienthes falcataria. ) (Indonesian). Unpublished
6.Subiyanto, B. and E.M. Alamsyah. 2002. Study on wood mass acacia mangium in variation of diameter at breast height (DBH) (Indonesian). Unpublished.

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