1) Tripogon japonicus OHWI is an endemic species of Japan occuring only in the northern part of the Kanto district, namely in Ibaraki and Tochigi Prefectures. It is always found on the almost vertical cliffs of andesitic agglomerate or andesite (Fig. 2). 2) The already-known, about 20 localities of Tripogon japonicus OHWI are shown in the geological map. (Compare with Fig. 1). 3) In the community of Tripogon japonicus OHWI, we can usually find Sedum Makinoi MAXIM., Hosta longipes MATSUM., Conandron ramondioides SIEB. et ZUCC., Lespedeza Buergri MIQ., Fraxinus Sieboldina BLUM. and Clethra barbinervis SIEB. et ZUCC. The floristic composition and the community structure are presented in Table 1.

抄録全体を表示

西南日本低地の極相林である常緑広葉樹林の,関東低地における分布の限界と,その気候的要因を考察し,残存林の組成や構造を調査した.残存林の分布は,神奈川・千葉・茨城各県の沿岸丘陵と,神奈川・東京・埼玉・栃木・茨城各県の山麓に多くみられ,群馬県には非常にすくない.また関東平野の中心部にもほとんどない.この内陸への分布限界は,寒さの指数-10°C線とほぼ一致し,この値は,数地点の残存林の垂直分布限界により,たしかめられた.野外調査の結果,いちじるしい優占種がみられず,種類組成にも,各林型の要素がまじり,基底面積も小さい林分が多いことから,極相林として十分に成熟し安定した状態に達していないことが指摘された.また群馬県の平野部と栃木県の那須扇状地は,温度的には分布の許容範囲にあるが,強い季節風の影響をうけて,原植生としての常緑広葉樹林を欠くことを推定した.

抄録全体を表示

大神神社の神仏習合の問題を考える場合、その隣接する長谷寺、更には東方の室生寺も併せて考察していかなければならない。いうまでもなく長谷寺は中世、三輪流神道の教義がうちたてられ、神道灌頂が行われ、神仏一体の信仰の中にあった寺である。室生寺は三輪流神道の創始者といわれる慶円上人(一一四〇〜一二二三)の伝承によると、三輪明神に灌頂の印明を授けたことは互為灌頂に示されているが、この灌頂の印明は八幡大菩薩より授けられた理智不二の印明であり、それは胎蔵、金剛の世界の究極の真髄を印・明という形で示されたものであり、これは三輪明神に授けられたものであるとともに、室生山の善女竜王にも授けられたものであると伝えられている。ここに室生、長谷、三輪は共通の信仰の地盤があることが推測される。

抄録全体を表示

Seed dispersal, seedling demography and the relationship between seedling position and the upper layers of the tree crown were studied in a Castanopsis cuspidata var. sieboldii forest on Mt. Nishikanasa, Ibaraki Prefecture, central Japan. For four years (1988-1991), dispersed sound seeds of tree species were collected at different intervals. There were differences in the numbers of seedlings that emerged on the forest floor as well as the position of seedlings in relation to the crown projection for each tree species. The results indicated that the seedling bank of C. cuspidata var. sieboldii can be maintained by changes in leader shoot and by sprouting of new shoots after damage within 10 years. Though C. cuspidata var. sieboldii and Abies firma seedlings appeared under the subtree layer crown, the positions of their seedlings in the shrub layer suggested that they survived and grew successively in places without subtree layer crowns. Acer palmatum var. amoenum and Carpinus laxiflora seedlings cannot survive if upper-layer crowns persist, and their seedling bank can be maintained if new seedlings are supplied. For Quercus salicina, seedlings can grow everywhere except for places covered by all crown layers.

抄録全体を表示

We studied the fauna hygropetrica of a mountain stream, Miyatani (Fig. 1), Ooto-mura, Yoshino-gun, Nara Prefecture, quantitatively. Table 1 shows the constitution of four quadrate samples, the size of the quadrate being 50cm×25cm. The results are summarized as follows : 1. All members of this community are small in size. 2. Standing crop of the community is little. 3. There are true hygropetric forms, such as Osmylus sp. and Nogiperla sp., almost true hygropetric forms such as Stactobia japonica and Psychomyia sp., and indifferent forms such as Mystrophora sp., Micrasema sp., etc. 4. When the wet rock is covered with mosses, as quadrate No. 4,its community is more or less different from that of the bare rock.

抄録全体を表示

While we have seen significant development recently in the study of castles in medieval Japan, the research on these spaces during the early medieval period leaves a lot of areas to be explored. Also, such research themes as the castle in relation to graves and holy ground have brought to the forefront the important mental or psychological aspects of the castle. In the present paper, the author examines the conditions of existence for and mentality surrounding the castle in early medieval society. First, the author uses such source materials as the Azumakagami and Heike Monogatari to investigate the actual conditions of castles during that time, and finds that what is called jo 城 and jokaku 城郭 (with the exception of these terms being used for Kyoto) does not appear in the realm of everyday life, but rather at extraordinary times of war and rebellion. The castles that appear here were usually built on open plains for the purpose of combat between individuals on horseback. In many cases their structural character included a relatively simply one story line of defence encompassing a particular space. The phase jokaku wo kamau 構城郭 (lit. build a castle) actually meant to take a stand within this defensive position, or space. The author then investigates the various ways of thinking at the time about where to set up defensive positions, in order to discover the territorial character of the places where warriors "took their stands". In many cases areas deeply related to religious belief like temples and shrines were chosen. For example, Kinugasa-jo built by the Miura family during the Genpei War was set up on a mountain considered to be holy ground and a sutra mound (kyozuka 経塚) was even constructed within the emplacement. Miura Yoshiaki's reason for taking a stand in this particular place (according to the Engyo 延慶 version of the Heike Monogatari) was to die in a castle so well known that both his ancestors and the enemy would not fail to hear of it. Mt. Kinugasa was chosen as a defensive position because it had important religious significance (including ancestor beliefs) for the Miura family. There are many cases in which this very psychology worked in the selection of holy or spiritual places as castles in early medieval Japan. Taking this particular mental aspect into consideration, we can also see the spacial significance of Akadani in Echigo Province, were the Jo family built a castle in which they prayed to the bodhisattva, Sudristi (妙見菩薩; Buddhist deification of the North Star),to bring misfortune down on the Genji forces. The author also points out that both Mt. Kinugasa and the area around Akadani had strong connections to mountain beliefs and ascetic practices (Shugen 修験), and surmises that warriors who built their defenses in mountain areas in many cases called upon mountain ascetics (yamabushi 山伏) to guide them into holy, sanctified ground. This is how, for example, the Satake family of Hitachi Province took their stand at Kanasa Shrine and then fled after their defeat to the hallowed ground of Mt. Hanazono, the Jo family built their castle at Mt. Totsusaka, the holy ground of Haguro asceticism, and why during the rebellion of Kiyohara Iehira (Go-sannen-no-Eki; 1083-1087), Fort Kanezawa was built on the sacred site of Gionji temple, the starting point for mountain pilgrimages.

抄録全体を表示

棚倉断層沿いに発達する中新統は日本海拡大期の左横ずれ運動によって形成された横ずれ堆積盆を埋積したものである．そこに挟在する男体山火山角礫岩は，組成がアイスランダイト質であり，日本海拡大と密接に関係しているものと考えられている．主に堆積相解析を用い，火山体（男体山海底火山），火山活動の詳細を検討した結果，男体山海底火山は複数の噴火口をもつ複合火山であり，非爆発的な噴火を連続して起こしたことが明らかになった．当時の男体山海底火山周辺の古応力は，男体山火山角礫岩中の石英脈の方位がNE-SWからENE-WSWに揃うこと，沈降場であったことから，NW-SEからNNW-SSE方向の引張軸をもつトランステンション領域における応力場であったことが示唆される．棚倉断層の横ずれ運動によるトランステンションの応力により地殻が破断し，下部地殻の部分溶融起源のアイスランダイト質マグマが急速に上昇，噴出した可能性が高い．

抄録全体を表示

From February, 1984, to June, 1986, twenty-one Japanese squirrels (Sciurus lis; 11 males, 10 females) were reintroduced into Shinjuku Gyoen (58 ha) in central Tokyo. However, squirrels were not observed since December 1987. This report summarizes the issues related to the reintroduction of squirrels based on the results of this project and the ecological knowledge on squirrels produced by subsequent research. Approximately 36 ha of the forest were used by squirrels. The main foods were walnut and Lithocarpus edulis acorn from feeding stands, seeds of Pinus thunbergii, P. densiflora, exotic conifer trees, and Castnopsis cuspidata var. sieboldii acorn. Three carcasses of squirrels predated by Felis catus were confirmed, and Corvus spp. chased the squirrels. The squirrels did not settle because the forest area of the site was not sufficient considering the home range of squirrels; there was no habitat to move to close by, and dependence on acorns as forage was overestimated. Issues: 1) forest area of the site corresponding to the home range size of squirrels, 2) conservation of forests with diverse tree species, and 3) management of feral cats and crows as predators.

抄録全体を表示

  1.　八溝山地および阿武隈山地,北上山地を中心とする東日本太平洋側におけるブナの分布について,標本(196点)および文献(233件),研究者からの私信(28件)を情報源として分布情報データベースを作成した.さらに,これに基づいて72地域で現地調査を行い,あらたに206個体のブナの分布データを得た.
  2.　上記の分布情報を解析した結果,ブナはこれらの山地に点々とではあるが水平的に広く分布し,垂直的にも海抜約100m前後から1000m以上の広範囲に分布することが確認された.
  3.　ブナの垂直分布下限は暖かさの指数WI=90℃・月,寒さの指数CI=-10℃・月,1月の平均気温=1℃とほぼ一致した.ブナは常緑広葉樹の分布上限(北限)に平行して,一部,分布を重複させつつ,分布下限(南限)を形成していることが明らかとなった.
  4.　ただし,内陸に位置する八溝山地中部の鶏足,鷲子の両山塊とその周辺地域では,ブナの垂直分布下限が著しく下降しWI=105℃・月まで達していた,この地域は関東平野内陸における常緑広葉樹の分布北限域であり,冬期の低温や季節風が常緑広葉樹の分布を限定的なものとしていることや,植生史的にみて常緑広葉樹林の分布拡大が遅れたために,ブナの個体群が低海抜地に遺存分布していると考えられた.
  5.　ブナの分布下限を規定する要因として,常緑広葉樹との競争関係が重要と考えられた.
  6.　東日本太平洋側において,ブナが種としては低海抜地まで分布するにもかかわらず,ブナ優占林の分布が比較的,高海抜地に限られる原因について推論した.
  7.　ブナの垂直分布域は,緯度的に南部に位置する八溝山地・阿武隈山地では山地の山頂付近を除き大部分,下部温帯域に含まれるが,北上山地では,上部と下部を含む温帯全域に及んでいることを指摘した.

抄録全体を表示