Search

A study was conducted on Orthoptera (Acrididae, Tettigoniidae, Gryllidae) in 56 sites of reclaimed land of Kanazawa District, Yokohama City, Kanagawa Prefecture through May to October of 2008. 28 species and 1941 individuals were recorded during this study. By using TWINSPAN and partitioning, classifications of the Orthoptera and study sites were made based on the results of this study. Also we investigated concerning vegetation, soil, distance from original land,and area coverd with vagetation around field as environmental factors. The study sites were sorted into 5 groups and the Orthoptera were sorted into 4 groups by using TWINSPAN. Based on 5 study site groups, partitioning analysis was conducted.Results suggest vegetation height, coverings of evergreens and deciduous trees of middle to high height, and distance from original land are related to Orthoptera inhabitation. However, it has not been clearly understood the distance from original land was selected as explanatory variable. A further verification is necessary because of the possibility that area coverd with vegetation around the field is related was suggested.

The International House of Japan was established in 1952 for the purpose of promoting international exchange and mutual understanding. The present location of the house used to be the residence and garden of Koyata Iwasaki, the fourth president of the Mitsubishi Zaibatsu, which resided from 1930 to 1945. The residence was destroyed in the war destruction in 1945 and was replaced by the International House of Japan ten years after. The purpose of this study is to achieve clarity of the spacial structures of Iwasaki residence and the current International House of Japan. The study was taken place by, first of all, searching for scattered records, and analyzing the documents in the periodical order. Secondly, the present state of the garden was cleared up by surveying the placements of plants and rocks. Finally, the spacial characters of the Iwasaki residence and the International House of Japan were compared to clarify the changes that took place in the transformation phase. As a result of this analysis, the spacial features the Iwasaki residence became clear ; it carried a courtyard, a tea room, a fall and a running water, with the architecture and garden intricately entwining. Meanwhile the International House of Japan which inherited the garden from the Iwasaki residence took a different approach in dealing with the garden ; the architecture kept some distance away and placed a vast lawn garden in between. Rooftop garden were also installed to be correlated with the garden while meeting the modern architecture style.

Japan's Environmental Impact Assessment Law was enacted in 1997. However, there are still many problems in Japan's ecological impact assessments. Among these problems, we turned our attention to problems stemming from 1. The system of Japan's EIA ; 2. The team of EIAs ; and 3. Technical methodologies. We applied the Habitat Evaluation Procedure for the first time to an EIA in Japan. Through this experience, we reviewed effectiveness of HEP as a solution to the above problems in Japan's EIAs. The proposed project was a residential development in Yokohama. The site was located in one of the largest remaining natural suburban areas in the city,consisting of densely vegetated hills and creeks which provide quality habitats to wildlife including fireflies and brown frogs, selected as evaluation species in this HEP. Some modifications of original HEP were introduced, including technical revision for the fragmented natural area which has a peculiar land use in Japan. As a result, HEP contributed to formation of substantial mitigation measures for habitats conservation through analyses and discussions among HEP team members.

In this study, we tried selection the index species in frogs and toads, because it was necessary to verify the relation with the population density of the index species and the ecological location type in rural landscape planning. The fauna composition and seasonal changes in the number of frogs was investigated by visual encounter survey and audio strip survey in hilly area, northern Kanto in 2006. Two species, Rana japonica and R. porosa porosa, has been selected as the index species for evaluation of the habitat quality. And the evaluation by the calculation value of yearlings should be low validity, and use the calculation value of adults. The suitable investigation season of two species for quantitative survey was clarified. In addition, it was shown that the presence of R. rugosa was able to become indices of various frog species composition when limiting it to the environment where the rice field existed.

This paper proposes an environmental evaluation method in units of small watershed in order to discuss the guideline for the landscape management considering the conservation and restoration of the local biodiversity on scale of city or district. The Survey area is Kamakura city and the evaluation species are two frog species; Rana ornativentris and Rhacophorus schlegelii. The combination of biotope types is one of the important factors in the habitat environment. Firstly, biotope types were classified as habitat of each evaluation species for the breeding and non-breeding season based on the biotope map of Kamakura city. The combination of the biotope types of each small watershed were evaluated as the habitat potentiality. The correspondence of evaluation results to actual habitats validated the evaluation method. Secondly, the small watersheds were classified into six types of environmental character by cluster analysis using indices of the land features and land cover. Furthermore, to combine the environmental characteristics with the evaluation result clarified the environmental potential of each small watershed type as habitat of evaluation species.

The significance of biodiversity has been widely accepted in recent years. In this context ecological information are indispensable for regional landscape planning in both urban and rural areas. In the present study, we propose a procedure to estimate species distribution in a rural area using amphibians as materials. Estimation model of potential habitats was constructed based on the relationship between amphibian species composition and land attributes. The investigation of amphibians in 24 sites was performed in and around Mito city, central part of Ibaraki prefecture as a case study. The percentage of inhabitation of each species was calculated by the current situation of the amphibians in the investigation sites, and the 8 types of fauna composition were identified using TWINSPAN. Then, landform types and vegetation types were classified by GIS. And the discriminant function which classifies each fauna composition type was computed. In the first stage, it was divided into hilly areas and plateau/lowland areas by landform classification. Hilly areas are characterized by habitation of three amphibian species; Hynobius tokyoensis, Rana ornativentris and Rana rugosa. In the following stage, the more detailed division of each fauna composition type, which was explained mostly by the present situation of Hyla japonica, Rhacophorus schlegelii and Bufo japonicus formosus was possible by using vegetation classification. The discrimination ratios of predicted inhabitation were between 65 - 86 %. We calculated the potential habitation possibility of amphibian species in the non-investigated area using the obtained distinction function formula. The map of the predicted habitat of amphibians was created about 840 km2 of the case study area with a grid cell of about 1km around. In addition, verifying investigation was conducted at 13 sites and the validity of the predicted potential habitat map was accepted. By establishing a series of research flows for the prediction technique, the application of a broader-scale landscape planning was attained.

The belt-transect survey at a scale of 1:25000 was investigated in order to clarify the relation between the inhabitation of frogs and the landscape structure in the Isawa alluvial fan. The index value of frog abundance was investigated and obtained by counting egg masses and by the hearing density of calling. The invasion situation from the hill of each frog to a large paddy field region has been understood. The breeding site of brown frogs Rana japonica and R. ornativentris, was restricted to the edge of the alluvial fan. Also under the cliff of the terrace side where water oozes out in the spring, the breeding site for both brown frogs existed in a detached district of the fan. As for R. rugosa and Rlacophorus schlegelii, the inhabitation was found only in the southern fan region. It was hypothesized that the existence and quantity of a ground waterway network and small pieces of wood were the distribution restriction factors for each species. In contrast, Rana porosa porosa inhabited in the whole region of the fan by a high density; especially it was remarkable in the northern fan region where it currently improved by rectangular field plotting. For this reason, the investigation year of 2001 has many land consolidation paddy fields, which are comparatively old now, and it is possible that the majority of the ground waterway still remained.

水田を有する都市公園は, 農的景観や自然に触れる機会の少ない都市住民にとって貴重な空間となっている。このような二次的な自然は人為管理が不可欠であり, その担い手の確保が今日的な課題である。本研究は, 水田を有する都市公園の実態を把握するとともにその維持管理の体制について考察検討を行った。東京都および隣接3県において, 水田を有する公園は計29箇所抽出された。公園内の水田の維持管理作業においては, ほとんどの公園で市民参加方式を導入しており, 参加形態としては季節ごとのイベント的な管理作業から通年管理作業まで見られた。維持管理体制には, 行政主体から市民主体まで幾つかの種類が見られ, それぞれの特徴について考察した。

アカガエル2種について非繁殖期の樹林内での生息を調査し'その確認地点の植生構造から環境嗜好性を分析した。両種は落葉広葉二次林, シラカシ林, スギーヒノキ林のいずれも生息場所としていたが, ニホンアカガエルはシラカシ林に負, 落葉林に正の嗜好性を示した。ヤマアカガエルは樹林タイプを問わず樹林の内部への嗜好性が示唆された。林床環境の5要素で判別分析を行った結果, シラカシ林は草本ll層, スギーヒノキ林では草本1層, 落葉林では草本l層・ll層の被度落ち葉量の各変数項目が関与していた。人為撹乱による明るく草原的な環境と暗い林内の環境を両極とした両種の環境選択の勾配軸が認められ, その植生管理について考察した。