| Research Abstract |
It is well known that the chestnut is not only the most important food resource but also timber resources for people of the Jomon Period in Japan. To cut trees for wood resource is fundamentally conflict to get nuts for food, How the Jomon people resolved the conflicting two purposes is the main theme of this project
For the purpose, we firstly researched how amounts of chestnut trees are in natural forests. It was come to appear that chestnut is 378-558 trees / hectare, 14.8-55.1 square meter of basal area /hectare in natural secondary forest of northern Honshu. Secondary, we researched how the chestnut trees are recovered after timber cutting. As the Jomon peoples cut timbers by stone axes, we also tried to cut trees by stone axes and chain saw for comparing the recovery process by the different cutting tool. It became appear that if we cut chestnut trees only from nature forests, there are no or very few new chestnut trees would be grown
Thirdly we examined annual ring growth pattern of chestnut trees in recent forests and excavated chestnut wood. The annual ring growth is very slow in natural forests, fairly fast in secondary forests, and very fast in cultured chestnut trees. Most of excavated chestnut trees showed fairly fist growth and some are very fast growth, while few, very large excavated tree trunks (about 50 cm in diameter) showed very slow growth. As a result, it may said that most timbers used for house making were obtained from the secondary forests or from cultivated trees, while those of large constructicn might be obtained from nature forests
As the forth, we developed a DNA analyzing method, SSR (Single Sequence Repeat) maker, for analyzing DNA of excavated chestnut and compare with the recent chestnuts. Although we could recognize the presence of DNA in those materials, but do not yet success. It will be required to develop technical process for further researches
|
