Carex rugulosa Kükenth, a near threatened perennial marsh plant in Japan, occurs in coastal wetlands, such as coastal lagoon lakes, estuaries etc. This plant makes large stand in the river mouth of Ohashi River, Shimane Prefecture. However, large area of this stand is now planned to be removed, due to the flood control river engineering. Therefore, in order to conserve this large marsh stand, we conducted the observation on the life history traits of this plant.

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The number of research districts totaled 97, and the number of paddies researched totaled 455. Five species of frogs were found in the research area. Japanese Tree Frogs (Hyla japonica ) were found in all the paddies. Montana Brown Frog (Rana ornativentris ) and Wrinkled Frog (Rana rugosa ) were found unevenly distributed in the districts. There was a characteristic in the ratio of the number of frogs confirmed in each paddy within districts where the frogs were found.

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Fish numbers, stages of growth, and timing of immigration and emigration in planted paddy fields and in unplanted paddy fields were investigated and compared. Misgurnus anguillicaudatus, Gnathopogon elongatus elongatus, and Carassius spp. use inundated unplanted paddy fields as spawning and their fry’s growth areas in the same way as nearby planted paddy fields. However, three points should be considered when using unplanted paddy fields as biotope for fish; (1) if the timing of intake of water to unplanted paddy fields is relatively late, the paddy fields may not function as good spawning areas, (2) if water management of unplanted paddy fields is done carelessly, these fields may tend to frequently release paddy water, (3) if an unplanted paddy field has any structure preventing fish from easily escaping from it to an irrigation canal, many fish could be trapped in the paddy field at drainage time.

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This study clarifies the influence of barrage on the environment of an irrigation channel, and on the impacts to the habitat of freshwater fish in the irrigation channel. This investigation was carried out from June 2004 through to January 2006 in the Mukoujima-channel, Hino Tokyo. As a result, 1) Sections of upper barrage were deep and there were slow-moving pools where sand and silt were piled up during the irrigation period. 2） The density of Oryzias latipes latipes, Carassius sp., Pseudogobio esocinus esocinus and Cobitis biwae was high in sections of upper barrage.

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Cypripedium macranthos var. speciosum is an endangered species in Japan，inscraibed in the list of "The Law for the Conservation of Endangered Species of Wild Fauna and Flora". To avoid the extinction of this plant species， the multiplication by artificial culture is thought to be the most effective methods. After Knudson succeeded in the germination of orchid plant in aseptic culture including three major nutrients and sugar in 1922, a lot of studies on orchid aseptic culture have been done. However, the artificial culture of C. macranthos var. speciosum has little succeeded. This study is thought to initiate the successful method of the artifecial multiplication of this valuable plant. To use as the reference materials for species preservation and environmental conservation, seed germination and nursery growing by aseptic semination were examined.

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The release of the crested ibis, nipponia nippon, is planned for the fall of 2008 in Sado, Japan. For the successful settlement of this bird, nature restoration has been promoted within two major frameworks: improvements in the natural environment and in the social environment. This paper examines theories and issues associated with the development of the social environment in Sado, on the basis of the research conducted as a part of the Toki Island Project started in April 2007 (Global Environment Research Fund, the Ministry of Environment). Possible solutions to the identified issues are provided in terms of an agenda for a community development workshop. The paper further examines the educational values involved in the workshop in order to ensure a democratic nature restoration process.

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The importance of extending the object of environmental restoration to the watershed is recognized, but technical theory which is an essential instrument of the environmental communication on the watershed is undeveloped. This cause is that actual technique is with drawing into the special technical field, and cooperation between each field is not enough. I learned four technologies (soil purification method, low-load semi- batch activated sludge method, air-suction and air-flow microbial fermentation method, Koyama-Kishi bottom mud aerobic conversion method) which are supposed to contribute to environmental restoration of the watershed, and built up my experience. Then, my technical level had been evaluated objectively by some examinations of the professional engineer test of national qualification. The above-mentioned technical disciplines registered as professional engineer indicate that results. Since combination of experiences and continuous study concerning with that specialized fields, I constructed a field-integrated and summarized technological model in regard to environmental restoration of the watershed. Now, I propose the model as an engineer.

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We researched the relationship between the thinning intensity and the recovery of understory vegetation in Japanese cypress (Chamaecyparis obtusa Endl.) forest around Ogasayama, Fkuroi City, Shizuoka Prefecture. The attempted thinning intensities were 20%, 40%, 60% and 80%. The result is as follows: At 20% area, the recovery of understory vegetation was slow and poor and the other areas, it was rapidly recovered and species diversity was increased. However, at 60% and 80%, the amount and specific diversity of lower vegetation were decreased after years by the growth of pioneer trees. Forty percent thinning is the most effective to produce the forest of rich specific diversity. At higher intensity, the control of pioneer trees is necessitated.

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Present and future regimes of ecosystem-restoration work in Tokyo Bay were reviewed, in which some reconnaissance attempts for the restoration are described.

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The wetland has various functions such as the purification function of the water resources, the flood prevention function, the relaxation function of the weather, the preservation function of the creature kind and the water quality and an environment education function. Recently, the water and plants environment at the bog in agriculture and forestry areas has become a serious problem. In this paper, groundwater level, outflow discharge and water quality were investigated in the Tashiro bog, Aomori prefecture. It was clear that the characteristics of groundwater level, outflow discharge, water quality and conservation in the bog.

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Community-based organizations, such as NPOs and NGOs, contibuted remarkably to the estuarine environment in Yokohama area in the last decades. Although their activities still contain problems to be improved, their presence has clearly influenced alteration of total framework of the social system. In order to vitalize future activities, the author reviews their activities and their social background in recent decades.

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Ishigaki Island in Okinawa is enriched with variety of world-famous valuable corals. Top soil of the island, widely-called red-colored soil, is easily eroded to damage beautiful coral seas when it is under influenced by human activities. This paper intends to analyze the cause of the top soil erosion/nutrient runoff from farmlands regarding farming systems and nutrient-reproducing systems. As a result, the followings are clarified: (1) large-scale farming system for mono-cultivation of cash crop is the primary cause of top soil erosion, and (2) lack of soil structure due to fertilizer use is the secondary cause to increase the top soil erosion. Based the cognition that agriculture business model with both high efficiency in top soil erosion prevention/nutrient runoff reduction and high profitability is needed, the followings are proposed: (a) re-evaluation of traditional intercropping style which had been assimilated to the sub-tropical climate in the island, and (b) introduction of cultivation-animal-husbandry-network for compost-recycling/energy-generation systems of animal excreta.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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Organisms make their cells, tissues and organic compound from chemical elements in environment around them through the history of living things. These elements circulate in environment continually from inorganic subsystems to living organisms. This review focuses on the elements important to human nutrition, and traces their action in global biogeochemical material cycle. In the material cycle, living organisms act as transporters of the elements and well-kept natural environment is a supplier of nutrients to surrounding landscapes and agricultural fields. Through reconstruction of biodiversity and sound moving of life, nature conservation and restoration would have effects on human welfare.

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[in Japanese]

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