北タイ地方におけるラック作りの技術と宿主木について

抄録

The technique of lac cultivation in northern Thailand, including breeding of the lac insect (Laccifer lacca) and management of host tree plantations, are described. The historical changes in tree species used as host are also discussed.
 Traditionally, lac was cultivated on wild host trees. Since the introduction of the rain tree (Samanea saman) at the beginning of this century, lac has been cultivated in host tree plantations. Today, most local people believe the rain tree to be indigenous, as it has spread so widely as a host tree over northern Thailand.
 Lac cultivation, host tree plantation and rice cultivation are combined into an agro-forestry system in the farm household economy. In this system, the farmer engages in lac cultivation in the agricultural off-season to earn cash income in the short term. In the long term, the unstable income from rice production is supplemented by selling old host trees. Lac cultivation and agriculture thus complement each other.
 With the increasing demand for seedlac on the world market, Thailand has become one of the world's leading lac producing countries since World War II. With the boost of lac production, rain tree plantations have increased. Nowadays, these plantations are a very important source of timber for the local market. The rain tree plantation can be considered as an “endogenous forest plantation” in Thailand.