Research on the conservation-area model for maintenance of biodiversity and its use

本研究项目旨在建立生物多样性维持和利用的保护区模式，并结合理论研究在屋久岛和琵琶湖进行了两次试点实地研究。在屋久岛的野外观测站，我们观察了从森林底部到树冠顶部的树木叶片和芽的动态，并评价了树木的垂直和水平结构在森林中的作用。这些研究表明，森林的结构可能是由树木个体间的相互作用产生的，结构越复杂，物种多样性越高。对琵琶湖的近海和近岸生物群落进行了调查。研究表明，沉水植物等大体生物产生的大尺度环境结构和微生物间营养物质的微生物环等小尺度环境结构是维持水生群落高度多样性的重要生态因素。此外，生物多样性可能取决于近海粘性流体（淡水）的物理特性所导致的非均质性，以及近岸降雨后养分流入所导致的环境波动，尽管这些环境因素维持了不同生态阶段的生物群落。因此，除了自然环境在时间尺度和空间尺度上的异质性外，生物本身产生的环境异质性应促进创造和/或维持更高的生物多样性，无论陆地或水生生态系统如何，温带或热带地区如何。因此，生物多样性较高的保护区应包括相互作用的生物在生态链系统中发挥作用的环境。

This research project aimed to build up the conservation-area model for the maintenance of biodiversity and its use, and conducted two pilot field-studies in Yakushima Island and Lake Biwa combining with the theoretical studies.In the field station at Yakushima Island, we observed the dynamics of leaves and shoots of trees from the bottom of forest to the top of crown, and evaluated the role of vertical and horizontal structures of trees in forest. These studies suggest that the architechture of forest might be produced by the inter-individual interaction among trees, and the more complicate structure maintains the more high diversity of species.In Lake Biwa, we investigated the offshore and inshore bio-community of the lake. The studies reveal that the large-scale environmental structure produced by the large-body organisms such as submerged plant and the small-scale environmental structure including the microbial-loop of nutrients among the micro-organisms are the important ecological factors to maintain the high diversity in the aquatic communities. In addition, the biodiversity might depend on the heterogeneity in the offshore due to the physical characteristics of viscous fluid (freshwater) , and also the environmental fluctuation in the inshore due to the inflow of nutrient after the rain, though these environmental factors maintain the bio-community with different ecological phases.Thus, in addition to the time-scale and space-scale heterogeneities in the physical environment, the environmental heterogeneity produced by the oraganisms themselves should promote the creation and/or the maintenance of higher biodiversity, irrespective of the land or aquiatic ecosystems, and of temperate or torpical areas. And hence, the consevation-area for higher biodiversity should include the environment for interactive organisms to function the ecologically chained system.