| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1993: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1992: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1991: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Research Abstract |
In 1973 and 1974, five permanent plots were established in sugi(Cryptomeria japonica D.Don) natural stands on Yakushima, an island off the south coast of Kyushu, Japan's southern-most main island. In this project, remeasurements were made on three of the permanent plots in 1991-1993. In our previous project, remeasurements have been made on two of them in 1988. From these remeasurements, the stand structure, its changes and the growth of these stands during the interim was analyzed.
The percentage of the basal area in the groups of sugi and other coniferous trees was about 70-80% in each stand except Shiratani permanent plot. No changes of dbh-height curves of sugi and broadleaved trees occurred, but among plots large differences were recognized. No regeneration and ingrowth of sugi were recognized in any stand. The two generations of sugi, which were divided at the point of about 90-100 cm of dbh, were noted by using an analyzes of dbh-distributions, growth patterns of dbh classes, and crown-structures. The net growth-rate of sugi, including the ingrowth, was -0.26%-0.62%. The one of broad-leaved tree and whole stand are -1.72%-1.19% and -0.17%-0.68%, respectively.
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