Hirokazu Oku

The change of a satoyama landscape and its causality in Kamiseya, Kyoto Prefecture, Japan between 1970 and 1995

We focused on patterns of land use in a particular satoyama landscape (Japanese traditional rural landscape, comprised of an integral social and ecological network of a village and its surroundings, such as agricultural lands, open forestlands and forests), and the effects of human activities upon them during Japan’s economic growth of the last few decades. Changes of landscape patterns and their probable causes were traced since the beginning of the 1900s to the present, and clarified. Societal, economic and technological changes, especially those that occurred after 1970, were considered the focal points from which major landscape changes developed. We compared the spatial features, patterns of land use and landscape diversities of each land unit, defined in terms of both their natural and man-made conditions for the year 1970, to those of 1995. We found land-use diversity to be strongly related to changes in the patterns of land use, with a decrease in diversity for all land units after 1970. Diversity of forest-age distribution on the other hand, increased. These changes, with the complex, changing patterns of each land unit, could be explained by differences in accessibility from the village and variations in the topography, as well as land ownership of the land units. We selected those land units found to have responded to these factors between 1970 and 1995, and classified them into four types of pattern changes, determined mainly by accessibility and topography.

The relationships between the structure of paddy levees and the plant species diversity in cultural landscapes on the west side of Lake Biwa, Shiga, Japan

Paddy levees form networks of narrow linear habitats and play various roles in cultural landscapes. Traditional landscapes on the west side of Lake Biwa consist of paddy field terraces and both “stone” and “soil” levees that have been maintained by paddy field management using local resources. Paddy levees in this study site are principally classified into five different types. Our study points out how differences in paddy levee structure as well as in management practices influence the plant species. Seventeen paddy levee transects were split into four habitat types based on their species components by TWINSPAN. Spatial characteristics and physical structures of paddy levees depended on natural conditions and human activities. The species–area curves of each levee type showed a clear distinction: the “soil”, “stone” and “abandoned” curves were steep, while the “concrete” and “consolidated” ones were gentle. The vegetation on “consolidated” levees was utterly different from the vegetation on traditional levee types from the aspect of species richness and species components. “Soil” type levees contained various woody plant species and included more diverse and indigenous plant species than “abandoned” type levees.

The biocultural link: isolated trees and hedges in Satoyama landscapes indicate a strong connection between biodiversity and local cultural features

Lone trees, rows of trees, groves, and hedges (in this study called “isolated trees and hedges”) dot many Satoyama landscapes in Japan. They have traditionally played an important role in agriculture and horticulture, in the production of firewood, and as windbreaks, boundaries, and screens. Through this investigation of a suburban Satoyama landscape in western Japan, which includes old and new residential areas, public space, farmland, and abandoned land, we aimed to show how isolated trees and hedges are connected with local traditional cultural features, and how this link has impacted their distribution and species composition. By examining land categories, shape patterns, and species compositions of isolated trees and hedges in both traditional and newly developed regions of the study area, we showed how the presence or absence of related traditional cultural features has influenced biodiversity. We further examined the role of traditional management techniques and cultural features in maintaining high numbers of local native species in isolated trees and hedges. Based on our results, we argue that awareness and promotion of the biocultural link in isolated trees and hedges will play an important role in future efforts to preserve the unique local identity and biodiversity of this cultural landscape.

Landscape Patterns of Isolated Trees and Small Isolated Woodlands in the Western Side of Lake Biwa, Shiga Prefecture

We clarified traditional rural landscape patterns, by surveying present states of distribution, utility forms and landmark on isolated trees and small isolated woodlands of satoyama in the western side of Lake Biwa in Shiga Prefecture. Isolated trees and small isolated woodlands are intensively distributed around the villages and farming areas. There are distinct characteristics of landscapes, such as peculiar narrow places of the land, organization of the type of trees and location concerned with the historical structures. Isolated trees and isolated small woodlands are classified into 23 landscape patterns according to (1) the connection with natural environment of the land. (2) the connection with agriculture and forestry. (3) the connection with social utilization as the living space. (4) the connection with the historical and cultural structures. By studying the direction of the landmarks and the meaning of places, isolated trees and small isolated woodlands can be said that they have carried out important roles in composing satoyama landscape peculiar to the districts.

A Comparative Study on Trees and Hedgerows in Japan and England

Japan and England have distinctive rural landscape patterns, resulting from the interaction of natural and cultural influences. Despite long-standing differences in land use and cultivation, there are many parallels in the infrastructure of their landscapes. In the 20th century, landscapes in the two countries underwent similar changes such as urbanization, abandonment of traditional land-management practices, depopulation of remote areas, and destruction of woodland and forest. The disappearance of old grasslands, trees and hedgerows on farmlands, and the destruction of trees by disease epidemics are familiar problems.

Reed community restoration projects with citizen participation: an example of the practical use of Satoyama landscape resources in Shiga Prefecture, Japan

Today, Japan strives to preserve some of its rural Satoyama landscapes in a sustainable way in order to ensure the survival of some well-functioning rural ecosystems in the face of continuing urbanization on the one hand and the neglect of such landscapes on the other. In the Lake Biwa watershed area in Shiga Prefecture, Satoyama landscapes comprise woodlands, grasslands, dry and wet fields, residential areas, and the lakeshore. The area today faces two major challenges: first, how to use local natural resources in a sustainable way to avoid further neglect or destruction of Satoyama landscapes; and second, how to reorganize the management of Satoyama forest and lakeshore resources. The results of our investigation showed how solutions to the above issues were found in the context of lakeshore projects aimed at restoring reed (Phragmites communis) communities, which are important component of the Lake Biwa Satoyama landscape. Since 2002, four such projects have been successfully undertaken through the efficient use of local forest resources, mainly wood and bamboo, in wave dissipation structures and jetties which facilitate the expansion of reed communities. Management was reorganized and now consists of stakeholders which include the original Satoyama management communities, governmental bodies, resident and nonresident citizens, and nongovernmental and nonprofit organizations. The projects are a unique attempt to revive Satoyama watershed landscapes, and may serve as models in other watershed areas.

Water Use and Landscape Formation Based on Topographic Factors in Two Mountainous Villages on the Tango Peninsula

This comparative study of the villages Kamiseya and Shimoseya in a mountainous area of the Tango Peninsula in Kyoto Prefecture, Japan aims to clarify the area-specific formation and spatial distribution of water sources, to research the river routes, and to investigate the characteristics of local water uses for daily life and for agriculture under consideration of the specific topographic factors in each village. Additionally, the function and role of the water uses in the areas landscape formation is analyzed. As a result of the investigation, it was concluded that 1. Water sources, water transportation routes and water uses in each village are closely related to local topographic features. Irrigation channels especially are instrumental in landscape formation. 2. Easy access to water sources in one village compared to difficult access in the second village resulted in highly different land uses and thus in substantially different changes of the landscape. 3. Locally specific water use patterns have cultivated local indigenous life traditions and culture.

A Relationship between Fish Communities and Habitat Environments in Small Erosion-controlled Rivers in the Lake Biwa Basin

The purpose of this study is to examine the relationship between fish communities and habitat environments in small, erosion-controlled rivers which until this day have been overlooked, and which have thus failed to be included in natural environment restoration zones. Thirty-one sites in three small rivers which flow into Lake Biwa were selected for investigation. As a result, six families and twelve fish species were identified. Based on the results of TWINSPAN, two categories of fish communities were established: the first comprised the communities found in the vicinity of the river mouth which included upstream migratory species such as Plecoglossus altivelis altivelis, and the second comprised the communities found in the middle course of the river which did not include upstream migratory species. It was inferred that the partition of the habitat space was the result of the existence of small dams in the river. The results of CCA indicated that although these small rivers had been significantly altered for erosion-control, a large variety of micro-habitat environments survived, and specific fish species inhabited the various habitats accordingly.

A Study of Landscape Evaluation Schema and Differences of Large Wind Power Generator between Residents and Visitors

The purpose of the study was to determine how landscape that contains large wind power generation is evaluated and to clarify the differences resulting from the comparison with nearby residents and visitors respectively. A wind power generator in Kusatsu City, Shiga Prefecture, was the subject of the present case study. Landscape evaluation was conducted in two residential areas, one of them close by and the second one further away, and in two tourist attraction locations, similarly at varying viewing distance from the generator, by means of a questionnaire survey. Analysis of the comparison results revealed that the visitors evaluated the landscape much more positively than the local residents. Moreover, it was clarified that landscape evaluation by the visitors tended to be influenced by viewing distance at a much higher degree than in the case of the residents. And the evaluation by the residents seemed to be less moderated by viewing distance. Further analysis showed that landscape evaluation by the local residents was strongly influenced by co-evaluation of other, related factors, and that their judgment was affected by a more comprehensive understanding of the landscape.

Fluctuation of Landscape and Satisfaction Evaluation with Sequential Change of Forested Trail(PAPERS OF THE 19th SCIENTIFIC RESEARCH MEETING)

オンサイトかつシークエンシャルな景観評価モデルに基づいて, 京都大学芦生演習林内のトレイルを対象として標識サンプリング法による調査を行い, レクリエ-ションサイトの景観計画に利用できる空間一人間行動系のパターンを見出すことを目的とした。43被験者による10ケ所のサンプリング地点での景観評価, 満足度疲労度についてのデータを集計し解析を行った結果, レクリエーション利用者が体験した景観に対する評価や満足度は, その地点の環境の物理的な要因と, シークエンスの移動に伴う要因の双方に影響を受けて変動することが示された。