Development of restoration and conservation technique for the disturbed island ecosystem in the Ryukyu Archipelago

探讨了琉球群岛岛屿生态系统受到各种干扰（如大量赤日进入海岸生态系统）后的动态与管理，并提出了恢复的方法。与位于冲绳那霸的亚热带研究所合作进行了珊瑚礁研究，并提出了一个管理珊瑚礁的想法，强调仔细考虑珊瑚、产卵者和育雏者的繁殖模式。亲鱼在不同的区域建立了当地的部落，但在产卵鱼中，基因交换的频率会更高。高温扰动后的微环境影响珊瑚的存活率。陆地和河流生态系统等提供的有机质是红树林区潮滩底栖动物重要的食物来源，但河流携带的碎屑也可能是重要的食物来源。在冲绳，万年青阔叶林以锥锥为主，而其它顶极林则不含锥，因此，在红树林的分解过程中，生长于分解树叶上的细菌植物群是红树林生态系统中重要的食物来源。西氏菌由于后一种森林受各种干扰的影响，其面积减少，其特征是物种多样性高，稀有物种的出现，因此对其恢复进行了讨论。研究结果为海岛生态系统的管理和恢复提供了理论和科学依据，即保持物种多样性和对未受干扰的生态系统进行选择性管理和保护尤为重要。

Dynamics and management of island ecosystem in the Ryukyu Archipelago which had been disturbed in various ways, e.g. inflow of huge amount of red day into shore ecosystems, were discussed and methods for its restoration were proposed. Research on coral reefs was conducted in cooperation with Research Institute for Subtropics in Naha, Okinawa and proposed an idea for the management of coral reef emphasizing the careful thought of reproductive modes of corals, spawners and brooders. Brooders established local demes in different areas, but gene exchange among sites was expected to be more frequent in spawners. Microenvironment affected the survival rates of corals after the disturbance by high temperature. Organic materials supplied from terretrial and river ecosystems, and so on are important for benthic animals on tidal flat as their foods in mangrove areas, but detritus carried from river system may contribute a lot. Bacterial flora developing on decomposing mangrove leaves is important food source in mangrove ecosystems.In Okinawa, evergreen broad-leaved forests dominated by Castanopsis sieboldii occur together with other climax forest without C. sieboldii. Since various disturbance affected in the latter forest, which is characterized by high species diversity and occurrence of rare species, and its area decreased, its restoration was discussed. Suitable habitats were detected for mongooses and wild cats, but anthropogenic disturbance affected their habitat and behavior in various ways.Theoretical and scientific confirmation were obtained for the management and restoration of island ecosystems, i.e. maintenance of high species diversity and selective management and conservation for undisturbed ecosystems are especially important.