The middle and lower course of the Chikusa River in Hyogo Prefecture, western Japan, was
divided into three segments on the basis of the characteristics of its longitudinal profile and
alongstream changes in channel slope. Further, quantitative analyses of sinuosity, excess
segment index, and channel width, and grain size analysis of river bed sediments were
performed in the same reaches.
The results indicate that each segment is characterized by a different channel pattern and
downstream change in grain size distribution, corresponding to the alongstream changes in
channel slope . This can be explained rationally as follows ; the longitudinal profile representing
the alongstream change in channel slope determines the alongstream change in tractive force.
Further, grain size distribution and movement modes of river bed materials are determined by
the tractive force, resulting in a change in channel patterns through deposition and/or erosion.
Thus, it can be concluded that the alongstream changes in channel pattern are controlled by
the characteristics of the longitudinal profile through the medium of the grain size distribution.
fault—bounded geologic units. They are generally arranged in tectonically descending order,
forming thrust sheets, namely: 1) Oeyama Ophiolite (fragment of Ordovician oceanic crust-mantle), 2) Akiyoshi Belt (Permian accretionary complex) , 3) Sangun Belt (high P/T type metamorphosed accretionary complex) , 4) Maizuru Belt (Permian to Triassic shelf deposits and Yakuno Ophiolite) , 5) Ultra-Tamba Belt (Permian accretionary complex) , 6) Tamba Belt (Jurassic
accretionary complex) , 7) Ryoke Belt (low P/T type metamorphosed accretionary complex) , and
8) Sambagawa Belt (high P/T type metamorphosed accretionary complex).
Thrust faults are rarely preserved on account of subsequent modification by folding and
high-angle faulting. However, regional mapping of the boundary between adjacent units and
laterally well-traceable rocks generally indicates that the enveloping surface of the folding of
thrust sheets , as well as their constituents , is comprehensively nearly horizontal or gently
sloping in various directions. In the distribution areas of the Ultra-Tamba and Tamba Belts,
there are many isolated distributions of erosional remnants and eroded areas of thrust sheets,
surrounded by structurally lower or upper units. They are comparable to the klippe and fenster
of nappe structure , respectively.
In the distribution area of the Sangun Belt, the Jurassic accretionary complex correlatable to
that of the Tamba Belt is exposed, and structurally overlain directly by the Sangun metamorphic
rocks without any intercalations of rocks assignable to the Maizuru and Ultra-Tamba Belts.
This fensterlike structure is thought to have been brought about by differential elevation and
denudation in this area to form a dome structure, newly named the Chizu Dome, and
remarkable contraction to produce a disorderly superposition of thrust sheet.
These preCretaceous rocks are highly likely to form a nappe structure, on the whole,
although the internal structure and lower order superposition of thrust sheets are not always
In order to evaluate the naturalness of vegetation through the species composition of
butterflies , butterfly assemblages were investigated . As we compared the results of route census
surveys of the whole year with the results once a year at five localities, it was recognized that
each value of the indices of species diversity and the average butterfly index of the two results
were closely similar. We investigated 19 localities in Hyogo, Osaka and Kyoto using a route
census survey once or twice a year. The values for species diversity and average butterfly index
were calculated for the 19 localities . The results showed that both the species diversity and the
butterfly index were highest in those localities at the substitutional stage of nature , and lowest
in those localities at the urban stage of nature. Analysis of these indices suggested that the
weighted average butterfly index is an effective index for evaluating the naturalness of vegetation.
Takatsuka—yama Bed, with a thickness of about 7.8m, is recognized as one of the most
important Middle Pleistocene layers distributed in the area along the eastern part of the Seto
Inland Sea (Harima Nada) , western Japan, because of the well—preserved and abundant
molluscan shells and the intercalation of a tephra layer.
We performed diatom and chemical analyses of the sediments from two outcrops, A and B, of
Takatsuka—yama Bed. The sediments are divided lithostratigraphically into three units, I , II
and III , in ascending order. The results of the diatom analysis show that unit I was deposited
in freshwater conditions, its upper part in standing—water conditions, such as a swamp or a
lake. Unit II , containing abundant molluscan fossils, and Unit III are inferred to have been
deposited in marine littoral and shallow marine conditions, respectively. Takatsuka—yama
volcanic ash fell during a time of marine regression before a Middle Pleistocene transgression,
because the ash layer is intercalated in unit I .
The variation in the sulfur content of section A is roughly consistent with the sedimentary
environments inferred from the diatom assemblages.
In potential natural vegetation, available habitats for Japanese macaques have almost prefecture—wide
distribution in Hyogo prefectural area. Rivers might play the role of the ecological barriers to
the animals which have such distribution. The analysis on riverside vegetation as ecological
resources for the macaques resulted that its quality is poor in the middle—lower—reaches and rich
in the upper— and the upper—end—reaches in comparison with respecting inland vegetation.
These results suggest that the middle—lower—reaches limit gene flow between macaque populations
on opposite sides of the river, and the upper— and the upper—end—reaches accelerate the flow
supporting the resident macaque groups or providing ecological corridors through solitary male
transfer. Gene flow system may have been similar in certain past periods, in which climatological
and geographical conditions were equivalent to the present conditions. On the other hand, large
genetic variation among actual metapopulations of this macaque has been found by recent
genetic studies. Generally, in relatively small—sized populations, the variation could be
intensified for the effects of random genetic drift must be actualized. These considerations
suggest that past Japanese macaque (meta) populations had period (s) when their sizes were
adequately small in several parts in Honshu, Shikoku and Kyushu and after such period (s) ,
these small (meta) populations spread out still keeping their genetic characteristics different from
Okinawa-tofu, which is a little harder and different from that distributed on the mainland of
Japan, is widely consumed in Okinawa. Other food items cooked together with Okinawa-tofu
were analyzed from the viewpoint of cookery culture. The analysis was based on data obtained
from The 80 Selections of Okinawa-tofu Cookeries. The simplest recipe considered was
sukugarasu-tofu , in which only the salted young rabbit fish called sukugarasu in the dialect is
placed on the tofu. Soy sauce and salt were most frequently used among the other foods. Oil
and butter were also frequently combined with the tofu in its fried recipes with eggs, or
vegetables such as onions, carrots, leeks, etc. These are called champurus. In imitation of
canapes as a new and modern European style recipe, Okinawa-tofu was also combined with
avocado, broccoli, caviar, etc. probably by the creator' s deliberate intention. From the
increasing number of food items corresponding to the increase in the kinds of cookeries, the
average numbers of food items used in one, 5 and 10 cookeries, were 8.1, 26.4 and 40.1,
respectively. The total number of food items used in all 79 cookeries was 166. According to
the ABC analysis of the food, 17 food items were found in 50% of all the tofu cookeries, and 50
were found in 70%. In a book, A New Compilation: 100 Amusing Cookeries of Tofu published in 1935, 370 cookeries were used, in which the number of food items used was 230.
But, there were no cookeries like the champrus in it.
Eupatorium fortunei in recent years has become rare due to the destruction of its habitat by
river improvement, although it was once widely distributed in southwestern Japan. Now, in
Japan, it is distributed in only nine rivers according to reports of the Rivers Bureau in the
Ministry of Construction. In the Kako River, in Hyogo Prefecture, about 200 individuals of
Eupatorium fortunei were found in 1995. We investigated the Eupatorium fortunei community in
the Kako River from the phytosociological viewpoint. As a result of the investigation, it has
become clear that the community is mainly distributed in the flood plain of the Kako River. We
held a seminar for environmental education involving the use of seedlings of Eupatorium fortunei
which were reared by us, and planted the seedlings in the Kako River for the purpose of
restoring the original state.
Botrychiumn ipponicum M akino is listed as an endangeredf ern in Hyogo Prefecture. Several
populations only are known at Kawanishi City in Hyogo. For a large population in
Kawanishi City, population size, floristic composition and habitat conditions were investigated to
provide basic data for conservation. At the studied site, 505 individuals of B. nipponicuma nd
114 of B. japonicum (Prantl) Underw. were found, some of which were small and appeared to
be juvenile. Data relating to the floristic composition suggests that both species grow under afforested Cryptomeria-Chamaecyparisf orest in company with deciduous trees (e.g. Prunus pendula, Prunus verecunda.) From habitat conditions, it is thought that they inhabit slightly elevated
position, and that B. nipponicump refers a lighter place than B. japonicum
The species composition of the soil seed banks of fragmented forests was examined in a hill
area of the southern part of Sanda city, Hyogo Prefecture. The forest vegetation of this area is
composed of secondary forests dominated by Quercus serrata and Pinus densifolia. The soil seed
banks of sixteen fragmentedforests dominated by Quercus serrata were investigated in June 1994 and January 1995. Forty tree species and three liana species were observed in the seed
banks (syzoochore 36 species, anemochore 7 species) . The most abundant seed bank species was Eurya japonica (evergreen small shrub) and also abundant was Quercus serrata (deciduous canopy tree) . The number of buried seeds and the percentage of viable seeds varied between the two seasons. The average seed density of the 16 fragmented forests was 513 seeds/m 2 /5cm depth in June and 811 seeds/m 2 /5cm depth in January. The percentage of the viable seeds in the two seasons was 64% and 31%, respectively. Total numbers of buried seeds in each fragmented forest varied from 1913 to 13 seeds/m 2 /5cm depth. Sixty—two percent of seed bank species also appeared in the aboveground vegetation. Twenty—three species were common to both the vegetation and the buried seeds. Four gardening tree species were found among the buried seeds . Eighty—four percent of the buried seed species were bird—dispersed species . The number of species and the seed density of the buried seed banks varied among the 16 fragmented forests, but the proportion of species dispersed from outside decreased with increasing patch size of fragmented forest.
The ovipositing behavior of Involvulus (Hyporhynchitesc) cornix is illustrated with photographs.
The weevils are shoot-stingers and the larvae are the stem-borers of Machilust hunbergii. The
female weevil makes rows of bites on the surface of a shoot preparatory to ovipositing. Two or
more holes are bored in a single shoot in most cases, and one or two eggs are deposited in
each hole. A cut across the shoot is performed after ovipositing, although it frequently appears
earlier. The cut is not complete and the piece of shoot is left hanging and becomes dry.
An endangered cyprinid, Rhodeus ocellatus kurumeus, was newly found in a small pond in the
Kako River System, Hyogo. This population is distinguishable from other populations in
northern Kyushu by such morphological characteristics as an increased body thickness, and a
greater number of branched soft rays of the dorsal and anal fins. These characteristics are
similar to those of the population in the Osaka area. Also, they were confirmed genetically to
be R. o. kurumeus by horizontal starch gel electrophoresis, directed particularly toward two
enzyme systems, LDH and PGDH.
The flora and the number of individuals of species planted as residential hedges were
investigated at a new town (Flower Town) in Sanda, Hyogo Prefecture. The results are as
follows : 1) A total of 44 species (including cultivar and hybrid) were identified in the hedges
of 2363 residents. 2) The Most frequent species were Camellia sasanqua, Quercus phillyraeoides,
Juniperus chinensis Pyramidalis (name of cultivar), Ligustrum vulgare, Photinia glabra,
Osmanthus x fortunei and Ilex crenata. Further, those residents planting one of the above
seven species as a hedge accounted for 80% of all those having hedges. 3) The total number of
individuals of all species planted as residential hedges was estimated at about 115447 individuals.
More than 100,000 wood buildings collapsed by the Hyogo-ken Nanbu Earthquake (Jan. 17,
1995. M=7.2). We researched the collapse pattern and direction of about 2700 wood buildings
from Takarazuka City to the northern part of the Awaji Island to estimate the shock directions
of the earthquake in the hypocentral region . The following remarkable features were observed.
Most of the collapsed wood buildings were damaged in a similar manner: their basal floors
were inclined or collapsed in a direction in the case both of one and two storied buildings,
although their second floors and/or roofs were not severely damaged.
Predominant collapse direction of the wood buildings was observed in the narrow zone,
Shi nsai no Obi (zone heavily damaged by the earthquake), from Suma to Takarazuka. In the
zone , five blocks were found out according to the collapse directions of the wood buildings.
The predominant collapse direction implies that a strong shock collapsed most of the wood
buildings in each block, and suggest that main shock directions were opposite to the collapse
direction in the blocks.