The fruit rain of the secondary Lauro- Fagaceae hardwood forest at Fu-Shan

From June 1992 to July 1993, 80 litter traps were installed in 1 ha area of the Fu-Shan secondary Lauro-Fagaceae hardwood foreat. Within this period, fruits in the litter traps collected were counted and weighted monthly. The fruits of 20 tree species were collected. The largest amount of fruits in the fruit rain belongs to Engelhardtia roxburgiana, next was Sapium discolor, Mallotus paniculatus, Diospyros morrisiana, and Elaeocarpus iaponica. The amount of the rain reached its peak varied with each species in this forest and that can be catgorized into three periods: (1) May to June, for Machilus species, (2) Lult to September, for Largeerstroemia subcoctata, Mallotus paniculatus, Diospyros morrisana, Elaeocapus japonica, Tutcheria shinkoensis, (3) October to December, for other spcies. Although Castanopsis carlesii var. sessilis is the dominant emergent tree in this forest, its fruit is rare in the fruit rain, which may be related to rodent consumption. The average fruit weight reached its peak at the time with the amount of fruit rain. The implication of characteristics of the fruit rain for natural regeneration of the secondary Lauro- Fagaceae hardwood forest is also discussed.1992年6月至1993年7月，研究人员在福山次生樟科-壳斗科（Lauro-Fagaceae）阔叶林1公顷样地内布设了80个凋落物收集器（litter traps）。试验周期内，每月对凋落物收集器采集到的果实进行计数与称重。本研究共收集到20种树木的果实，其中果实雨（fruit rain）中总果实量最高的物种为黄杞（Engelhardtia roxburgiana），其次为山乌桕（Sapium discolor）、野桐（Mallotus paniculatus）、罗浮柿（Diospyros morrisiana）与日本杜英（Elaeocarpus japonica）。 各树种的果实雨峰值出现时间存在差异，据此可划分为三个物候阶段：(1) 5—6月，润楠属（Machilus）物种；(2) 7月下旬至9月，南紫薇（Lagerstroemia subcostata，原文存在拼写笔误）、野桐、罗浮柿、日本杜英、香港石笔木（Tutcheria shinkoensis）；(3) 10—12月，其余物种。 尽管米槠无柄变种（Castanopsis carlesii var. sessilis）是该林分的优势上层乔木，但其果实于果实雨中极为罕见，该现象可能与啮齿动物的取食活动相关。平均单果重量与果实雨总量同步达到峰值。本研究同时探讨了该次生樟科-壳斗科阔叶林的果实雨特征对其自然更新的启示。