1990 Fiscal Year Final Research Report Summary
Stand Structure and Regeneration Dynamics of Old-Growth Chamaecyparis Stands in the Kiso District, Central Japan
| Project/Area Number |
63560151
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
林学
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| Research Institution | Okayama University |
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Principal Investigator |
YAMAMOTO Shin-ichi Okayama University Faculty of Agriculture Asso. Prof., 農学部, 助教授 (60191409)
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| Co-Investigator(Kenkyū-buntansha) |
CHIBA Kyozo Okayama Univesity Faculty of Agriculture Professor, 農学部, 教授 (10036741)
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| Project Period (FY) |
1988 – 1990
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| Keywords | Canopy gap / Chamaecyparis / Large-plot study / Litter fall / Kiso district / Regeneration dynamics / Seed production / Stand structure |
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| Research Abstract |
Stand structure and regeneration dynamics of old-growth Chamaecyparis stands in the Kiso district, central Japan, were studied during 1985 to 1990. A shape of dbh-class distributions was normal in Chamaecyparis obtusa dominated stands, but that was inverse J-shaped in a Chamaecyparis pisifera - hardwood stand. These shapes did not change for the five years. Mortality of canopy trees (dbh<greater than or equal>20cm) occurred in C. obtusa stand with 1.3-3.1% mortality, but no canopy trees died in the C. pisifera - hardwood stnd. Mortality of understory trees (dbh<20cm, height<greater than or equal>1.3cm) was 8.3-22.9% and the value of Thujopsis dolabrata was 12.2-22.9%. Abundance of new seedlings fluctuated annually ; many seedlings of C. obtusa emerged in 1986 and those of C. pisifera emerged in 1987 and 1989. Ex-posed mineral soils in a recently disturbed stand was the most favourable site for seedling recruitment of C. obtusa. Seed production of Chamaecyparis also fluctuated annually ; 4,479 seeds per sq. m of C. obtusa was produced in a abundant year and 4,324 seeds per sq. m for C. pisifera. Amount of leaf litter-fall was about 3ton/ha/yr in C. obtusa stands. There were 7,186 trees (dbh<greater than or equal>5cm) including 718 dead trees in a 4ha plot ; dbh class distributions of C. obtusa and C. pisifera were bimodal in shape without lacked classes and the kistribution of Quercus mon-golica var. grosseserrata was also bimodal but with lacked classes. The distribution of T. dolabrata showed inverse J-shaped. Canopy trees of C. obtusa randomly dispersed, but the understory trees did patchily. Canopy trees of T. dolabrata showed a nearly random distribution, and the understory trees occurred over a whole area in the plot. C. pisifera showed a nearly random in its distribution of canopy trees and a patchy distribution in the understory trees. Understory trees of Q. mongolica also showed a patch
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