This dissertation deals with the landscape of local Japanese Shint? shrines, which is significant in many respects. One key factor is that in the past, there were no shrine buildings, but only sacred places in the forest. Accordingly, the location of many shrines relates to the nature worship as part of the Shint? tradition. Three aspects are most relevant: First, shrines do not only consist of a building complex (shaden), but are above all social and religious places; second, they embody the cornerstone of former village development in Japan, and third they are closely related to beautiful, natural landscapes. Spatially, the approach road (sand?) connects the town with the shrine, and the deity grove (chinju no mori) behind the main building complex originally links the shrine site with the adjacent environment.

However, the common shrine seems to be under a considerable pressure of urbanization. Both the environment and shrine precinct are affected by changing land uses, such as road constructions and new buildings. Accordingly, the hypothesis is that there is a lack of conservation of both the environment and the green space within a shrine precinct. The purpose of this study is to explore the landscape condition of district shrines. Further, it encompasses the extent of changes within the 20th century. Finally, it investigates the actual legal conservation status of all case-study sites and discusses appropriate ways for a better future preservation.

In chapter one, the author explains the subject and outline of the work. The overall scope of investigation contains the actual landscape condition of district shrines, the most crucial changes that occurred in the 20th century, and the appropriate methods of landscape conservation. Furthermore, in this chapter, the author defines basic terms, which are frequently used in the thesis. Background information about the original meaning and space structure of Shint? shrines was also provided.

In chapter two, the author deals with the present landscape condition of the 28 district shrines (郷社) at the fringe of Tokyo. First, it described how the multiple case study sites were selected. The basis of selection for the sites considered their historical continuity until today. Thus, some of them it still represent the original shrine setting and landscape context. At the same time, these shrines are the ones that are more likely to be challenged by urbanization when compared to famous shrines.

Second, concerning the method, the present condition of the shrines was explored through site inspections, topographical maps, and satellite pictures.

Third, the results were presented. In terms of landscape setting, it was determined that half of the investigated shrines are located in flat areas, and half in sloping or on top of forested hills. This confirms that shrines relate to both topography and local scenic features. However, the fact that half of the shrines are located in the flat area, near rivers, suggesting that the common image of a "mountain-shrine relationship" should be re-evaluated. As for the green space, the most frequent pattern is a deity grove with a distinct spatial depth. Usually, such a grove extends behind the main building. There are also cases where the grove surrounds the whole precinct. In about half of the cases, single holy trees (shinboku), which are marked by a sacred rope (shimenawa), were also determined. Finally, the tree-lined approach road (sand?) was also observed. It can be said that the approach plays an equal important role as the deity grove around the main building for the landscape of a shrine site. The crucial point is that a "full green vista" has a strong effect on the spatial quality. If a visitor enters such a green pathway, the situation suddenly changes from a bright and often noisy townscape to a shady, quiet and refreshing green space. The significance of this point ? to create a space of transition ? was clearly supported by the comments of the shrine priests. The religious meaning of their green space was investigated through qualitative, half-structured in-depth interviews with shrine priests (kannushi). The priests stated that the overall forest scenery, which is provided by deity grove, is more important for a shrine than the single holy tree, despite the fact that the latter is in particular regarded as the residence of the kami.

In chapter three, the major landscape changes, which occurred during the 20th century, were described and analyzed. This chapter answers the question whether or not the district shrines were scenically impaired by the process of urbanization. Available historical maps and historical aerial photographs were analyzed in detail and compared, in order to show major changes concerning both the environment and the green space within respective shrine precincts. As a result, a very distinct urbanization was observed. Today, nearly all sites are surrounded by urban settlements. In terms of the green space, in about a quarter of the cases, a decline of the grove area and loss of single holy trees had been noticed. There is a major concern particularly about the loss of Japanese cedars (Cryptomeria japonica) and Red pines (Pinus densiflora). The death of those trees, which is caused by the lowering of the ground water and air pollution, is a loss of cultural significance.

In chapter four, the author relates the findings from chapter two (present state) with chapter three (landscape changes). Based on the results from previous chapters, the 28 shrines were statistically clustered into four groups. In order to illustrate detailed features, one in-depth case study site of each group was selected, investigated and discussed.

The in-depth-case study of group one, the Shakuji Hikawa Shrine, shows a favourable condition of shrine landscape. It is due to the combined effect of the shrine policy and local conservation ordinances.

The in-depth-case study of group two, the Kasukabe Hachiman Shrine, also still embodies a good shrine landscape. However, in contrast to the Shakuji case, the lack of nearby natural landscape relics, which could have worked as a buffer zone for the traditional shrine setting, resulted in a complete urbanized environment around the shrine precinct.

The in-depth-case study of group three, the Suwa Shrine in Tachikawa, represents a mainly impaired shrine landscape, caused by several factors. These factors could be due to the strong and early urbanization around the shrine precinct, and the related lowering of the ground-water level. Further impairments are the separation of the shrine precinct into two parts by a road and the loss of significant parts of its deity grove. Finally, during the last renovation, more attention was given to the large, representative architecture, but less for the improvement of the green space.

Finally, the in-depth-case study of group four, the Fudaten Shrine in Ch?fu, showed certain similarities with the Tachikawa case, especially in terms of its flat location, dense urbanized environment, and the similar loss of Japanese cedar trees. In addition, the loss and damage of its single holy trees revealed a lack of knowledge about how to treat them in an ecologically viable way.

According to these results, most district shrines in the flat areas are prone to be impaired, both scenically and ecologically, by a dense urban development around the site. In contrast, shrines on the slope of a mountain with natural landscape relics behind are likely to be in a better landscape state. However, this does not ensure the latter against further urban development.

Landscape conservation model for district shrines

Finally, in chapter five, the author explores the present legal state of landscape conservation and the maintenance problems from interviews with shrine priests and correspondence with responsible authorities. In conclusion, it becomes clear that that the actual protection is as yet insufficient. Despite the fact that an appropriate conservation always depends on certain local conditions, it is possible to make some reasonable proposals for better protection.

If a shrine site is still surrounded by some natural beauty, the task is to protect the context of the approach road, yard, deity grove and its environs. This can be achieved by a two-scaled zoning (compare right-hand graph). First, it is most important to protect the entire shrine precinct by implementing an inner zone. This is possible by designating the site as an Urban Park (Toshikoen), or, better yet, as an Urban Green Space Preservation Zone (Toshiryokuchihozenchiku). However, in order to avoid development along the shrine perimeter, it is necessary to protect the environment up to some hundred meters as an outer zone. While in some cases, a Scenic Preservation Zone (Fuchichiku) might be suitable, it is more likely that the Landscape Agreement Area (Keikankyoteikuiki) under the new Landscape Law is a reasonable tool to protect the overall landscape of district shrines.

In addition, it is very important to increase the promotion of the shrine-landscape protection in society. Shrine priests, schools and local authorities should work together to develop appropriate social activities.

本研究は、地域における身近な神社がその周辺環境を対象として、景観という観点から、その現状、変容の実態を明らかとしかつ保全のあり方について論じたものである。自然信仰を特徴とする日本の神社は、歴史的にみてその立地において自然環境に依拠しながら集落などの社会環境形成に重要な役割を果たしてきたことが知られ、その一帯に形成される景観は、地域固有の自然と文化を反映した性格を有するものとして持続的な地域環境の保全の観点から着目される。しかしながら近代以降の都市化の開発圧の中において、建築物としての神社は存続しながらも周辺を含めた景観には大きな変容がもたらされ、その保全が急務となっている。

そこで本研究は、東京近郊において明治期の旧社格で「郷社」に位置づけられていた地域コミュニティレベルの神社を対象に、その景観の現状と戦後の変容に関して実態を明らかとするとともに、その保全という観点から課題を整理し望ましい保全の方策について考察を行うことを目的とし、全体で5章からなる論が構成されている。

第1章においては、こうした研究の背景および目的を述べるとともに、研究の方法、既往研究の整理、概念規定等を行い、研究の全体構成を提示している。

第2章では、東京近郊(東京都、埼玉県、千葉県)に存在する28箇所の旧郷社を対象とし、その立地および緑地空間に関する実態調査を行っている。立地に関しては、社殿の存置形式を周辺地形および集落との関係から調査し、各事例において社殿の設置方向などから観察される信仰の方向性と丘陵や河川等の自然地形との関連等を明らかとしている。緑地空間については、一般に鎮守の森と称される各事例の社叢を主な対象とし、その規模(奥行き)、社殿の囲繞性、神木の存在・樹種及び位置、参道並木の覆蓋性、鳥居等の空間分節装置分布、路面の材料の連続性を指標とした調査が行われ、神社の緑地空間が形成する景観上の特質の現状が明らかとされた。調査は現地調査を基本として実施され、この際に各神社の宮司らに対してのインタビュー調査も行われ、宮司らの神社の緑地空間に対する認識についても明らかとしている。

第3章においては、上記の同一事例対象について、20世紀以降、戦後期を主体に現在に至る景観の変容に関する調査を行っている。景観の変容は周辺環境の変化および神社の緑地空間の変化を指標として、地形図、空中写真の分析に加えて宮司へのインタビューが活用されている。その結果、周辺環境の変化は基本的傾向でありながら、大きな変化の時期に事例間で差がみられること、緑地空間の変化については樹林地の減少、神木の消失、空間利用の変化、公園化など変化に一定の特徴があることなどを明らかとしている。特に神木については杉および松の衰退が著しいことが明らかとなり、量的側面のみならず質的、文化的損失の大きなこの変化が地下水位の変化と関連していることとなどが考察されている。

第4章においては、第3章での景観変容の結果をもとに多変量解析を用いて4種類に類型化し、それぞれについて詳細な景観の変容過程および要因を明らかとし、保全上の課題について考察を行っている。4類型は(1)過去の景観が基本的に維持されているもの、(2)景観が維持されているが一部公園化しているもの、(3)戦前から変容がはじまり緑地が縮退しているもの(4)戦後の変容が主で緑地が縮退しているもの、として整理され、各類型から一事例ずつを抽出して詳細調査が行われている。近世末期から現在にいたる景観変容過程とその要因が、古地図、古絵図、古写真に加え宮司への詳細なインタビューから分析された。その結果、自然環境要因としては地形等の立地条件や地下水等の環境変化が、社会環境要因としては神社自体の境内開発の経緯や行政による保全施策の経緯などが相互に係わる、各事例固有の課題として明らかとされている。

第5章においては、第2章から第4章までの調査を踏まえ、身近な神社を格とした地域景観の保全のための総合的考察が行われている。まず現行の環境保全施策として、神社およびその周辺に関係する法的制度を網羅的に抽出し、28事例について自治体独自の制度も含めてその適用状況を概観し、景観変容の実態と対照させることで各制度の得失について論じている。これを踏まえて今後の保全に向けた提言として、保全地域の区域設定に関するモデルを提示してまとめとしている。

以上本研究は、東京近郊の旧郷社を対象に、神社およびその周辺に形成された自然環境および社会環境の特徴の表出としての景観に着目し、その現状および変容の過程や要因を実証的に明らかとし、かつまたその保全のあり方についての提言を含めて論じたものである。本研究は今後の地域環境の保全において、自然環境と社会環境を総合的にとらえる視点とその保全のあり方に関する重要な知見を提供すると考えられ、学術上、応用上、寄与するところが少なくない。よって審査員一同は、本論文が博士(農学)の学位論文として価値のあるものと認めた。