Stand Structure and Regeneration Dynamics of Old-Growth Chamaecyparis Stands in the Kiso District, Central Japan

1985 ~ 1990年，对日本中部木索地区樟树林分结构和更新动态进行了研究。樟树优势林分的dbh-class分布呈正态分布，樟树硬木林分的dbh-class分布呈反j型分布。这些形状在五年内没有改变。黑松林分冠层树木（胸径<等于胸径20cm）死亡率为1.3 ~ 3.1%，黑松-硬木林分冠层树木无死亡。林下乔木（胸径<20cm，高度<等于bbb1.3 cm）的死亡率为8.3 ~ 22.9%，杜鹃的死亡率为12.2 ~ 22.9%。新苗的丰度每年都在波动；1986年长尾藤出现了很多幼苗，1987年和1989年长尾藤出现了很多幼苗。新扰动林分中裸露的矿质土壤是圆柏最有利的补苗场所。樟树种子产量每年也有波动；每平方4479粒在丰收年，每平方公尺可生产4,324颗种子。m代表C. pisifera。枯叶凋落量约为3吨/公顷/年。在4ha的样地中有7186棵树（胸径<等于胸径>5cm），其中718棵死树；黑栎和灰栎的胸径类分布为双峰型，不缺类；蒙古栎的胸径类分布也为双峰型，但缺类。大菱鲆的分布呈倒j型。冠层乔木呈随机分布，林下乔木呈斑块状分布。柽柳的冠层乔木几乎呈随机分布，林下乔木分布在样地的整个面积上。凤尾花在林冠乔木中的分布几乎是随机的，而在林下乔木中的分布则呈斑块状。蒙古松林下乔木也呈斑块状

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