Biogeographic study on plant distribution in forest islands.

对日本九州西部农村或城市地区孤立的25个森林地带或森林岛屿的植物区系和植被进行了研究。该项目旨在明确物种-区域关系和森林岛屿的临界大小，以保护稀有植物物种。所列植物总数为188种。在0.2公顷的土地上，最小的为29只，在23公顷的土地上最大的为114只。物种数量与肠道大小呈显著正相关（r=0.895）。所列植物种类根据其在自然环境中的行为和沿海到内陆的梯度可分为5类。物种组I是指在一些森林或受干扰的森林中发现的物种，V是指天然林或原始森林。种群V进一步划分为3个亚群，分别为0（广泛分布于天然林的种）、1（局限于内陆的种）和2（局限于沿海低地的种）。V类群（共0、1、2亚群）的物种数量与肠道大小无关，但受人为干扰和冲击的影响较大。研究的森林岛屿苔藓植物按其基质分为附生、附生和陆生3类。在这三组中，每一组都发现了局限于自然区域的物种。例如附生植物群中的后生金蜡菌（Chrysoclaldium retrorusum）、曲霉菌（Barbella asperifolia）和鞭毛菌（Neacroporium flagelliferum），附生植物群中的毛毛菌（Ctenidium capillifolium）、多毛菌（Eurhynchium polytictum）和双毛菌（Thuidium bipinnatulum），以及陆生植物群中的Calypogeia tosana和Rhizogonium dozyanum。

The flora and vegetation of twenty-five forested tracts, or forest islands, isolated in rural or urban areas were studied in western Kyushu, Japan. The project was designed to clarify the species-area relations and the critical size of forest islands for preserving rare plant species. The total number of listed plants was 188 species. The smallest number in a tract was 29 in a 0.2 ha tract and the largest was 114 in a 23 ha tract. The species number was positively correlated with the tract size (r=0.895).The plant species listed can be categorized into 5 groups according to their behavior in the naturalness and the coastal-to-inland gradients. Species group I was assigned to those found in seral or disturbed forests and V was to natural or primeval forests. The species group V was further classified into 3 subgroups of 0 (species distributed widely but only in natural forests), 1 (species restricted to inalnd) and 2 (species restricted to coastal lowland). The species number of group V (all together of subgroups 0, 1 and 2) was not correlated with the tract size, but strongly affected by human disturbances and impact.Bryophytes in the forest islands studied were classified into 3 groups according to their substrata as epiphytic, epilithic and terrestrial. In each of the 3 groups, species restricted to natural areas were found. Examples are Chrysoclaldium retrorusum, Barbella asperifolia, and Neacroporium flagelliferum in the epiphytic group, Ctenidium capillifolium, Eurhynchium polystictum, and Thuidium bipinnatulum in the epilithic group, and Calypogeia tosana, and Rhizogonium dozyanum in the terretrial group.