Phytosociological research was carried out in Aichi and Gifu prefectures where spontaneous growths of Ophiopogon japonicus var. caespitosus were found in the following two communities : Quercus variabilis community, which belongs to Carpinio-Quercion serratae, and Quercus variabilis-Quercus glauca community, which belongs to Ardisio-Castanopsion sieboldii. The potential natural vegetation of this plant's habitat belongs to Ardisio-Castanopsion sieboldii. O. japonicus var. caespitosus was found primarily in association with this alliance, whereas O. japoincus was not. O. japonicus var. caespitosus is connectsd to this alliance (forest) by a breeding system with the seed, as compared to O. japonicus, which has a breeding system with the slender rhizome. For these reasons, O. japonicus var. caespitosus can be recognized as one of the characteristic species of Ardisio-Castanopsion sieboldii.
The influence of low dilution rate (1.4-0.067 day^<-1>) on the bacterial flora was studied by using continuous mixed culture systems which were inoculated with activated sludge microflora and fed with a substrate solution of 500mg/l skim milk. The O_2-uptake rate and lactose removal rate of the microbial populations increased with the increase in dilution rate. The number of aerobic heterotrophic bacteria was the highest at the highest dilution rate, and the lowest at the intermediate dilution rate of 0.41 day^<-1>. The bacterial composition in the systems varied both at the generic level and also at the species level as the dilution rate varied. The isolates belonging to Flavobacterium-Cytophaga constituted a greater percentage of the isolates from the systems with higher dilution rates, but Acinetobacter-Moraxella was dominant in isolates from the cultures with lower rates. The relative abundance of bacteria with complex nutritional demand increased with the decrease in dilution rate. The isolates which were able to grow within wide ranges of temperature and pH and in the presence of some antibiotics made up decreasing percentages of the population at lower dilution rates.
The population dynamics of bacteria and a protozoa, Cyclidium sp., which have different growth rates, were studied using continuous culture systems containing only bacteria and both bacteria and protozoa. In these cultures, large numbers of bacteria formed flocs and some of the protozoa attached to the surfaces of these flocs. The flocs were rarely washed out from the vessels owing to gravity, but after reaching a critical size, they degradated into smaller flocs by the shear stress of aeration. The amount of flocs maintained a steady state due to the balance between formation and degradation. We concluded that the formation and maintenance of the bacterial flocs play a significant role in the population dynamics of bacteria and protozoa.
This report deals mainly with the relationship between the vegetation and the soil. The soil was derived from sand pump dredging. Four to five years have passed since the completion of the reclaimed land. We found the distribution of the vegetation units to be governed by the saline sequence, especially of the soil. A generally observed reciprocal action between the vegetation and the soil was not observed in this particular study. Instead it was clear that materials and methods of sand pump dredging influenced the microrelief more strongly than the salt content of the soil which brought about the growth of the type of vegetation units examined. Some developments of vegetation along with the leaching of salt in the soil were also discussed. In a future report we intend to describe the chronological changes in the soil and the vegetation.
The life history of a leaf-miner, Nepticula castanopsiella, infesting the evergreen leaves of Castanopsis cuspidata, was studied with a view toward its host-parasite relationships and the relationships to its environment. The life history of this species was characterized by diapause in summer and feeding in winter. This mode of life may be established by the following factors in the adaptive process. The eggs show temperature dependent diapause in summer when the temperature is relatively high especially for leaf-miners and when the natural enemies are active. The larvae begin to feed on food leaves after autumn when the leaves have become rich in nutrients. The leaf-miner favors the thermal conditions of its microhabitat by keeping the mine temperature higher than that of the outside during the cold season. The winter feeding of larvae was supposed to decrease the mortality of the leaf-miners by parsites. These things were supported by population dynamics, characteristic adaptations for temperature and bioeconomic properties.
The size variations of the climbing larvae were investigated in the Kiyotaki River, Kyoto, Japan, from April to May, 1976-1978. The weight, the length, and the relative condition factor decreased as the season advanced. Just before the larval climbing season, almost all of the larvae to the warer seemed to have enough weight to do climbing. Among them, the larger larvae seemed to do climbing first. In the laboratory, the emergence rate of the climbing larvae decreased under 16℃ as the season advanced and increased under 20℃. The larger and/or stouter larvae showed a high emergence rate at 16℃ and the smaller and/or leaner ones showed a higher rate at 20℃. These results suggested that the larger and/or stouter larvae which did climbing early in the season were adaptive to the lower temperature, and that the smaller and/or leaner larvae which did climbing late in the season were adaptive to the higher temperature. The size variation is an important quality within a population for L.cruciata which has an unique behavior of leaving the water to pupate only on the rainy nights in late spring when the air temperature rises steadily.
Adult females of Vespertilio superans superans arrived at a rock tunnel on an islet of Ohzukue-jima in April to form matenitycolony. Feeding activity of pregnant females began at about 10 minutes after sunset and continued until about 0200 hr, and that of lactating females had two peaks with a major one soon after sunset and a minor one before sunrise, while that of young was intermittent. Parturition occurred from late June to early July. Litter size averaged 2.0. Body weight of newborn young was relatively light, being ca.12% of the weight of postpartum females. The low ratio seemed to be closely correlated to the high frequency of multiple births and high wing loading of the mother bat. Lactation lasted an average of 35 days. Deciduous teeth (di 2/3,dc 1/1,dprn 2/2=22) present at birth were replaced by permanent dentition at 24 to 26 days of age. Eyes opened at 8 to 12 days, and afterwards the growth was accelerated. Most of the young females became gravid in the next summer. The adult females left the nursery colony soon after independence of their young ; and next the majority of young males departed. The remainder young emigrated in the middle or last decade of September.
Seasonal variations of freezing resistance in 42 pine species which were planted at Kamigamo Experimental Station of Kyoto Univ. (about 35℃ N) were investigated with special reference to two thermal indices, mean warmth index (MWI) and mean temperature in the coldest month (MTCM) in native distributional regions. The timing of cold hardening in Kyoto differed significantly among pine species ; The species from northern or colder regions became hardy earlier than those from southern or warmer regions. The winter hardiness was closely related to MTCM. The degree of hardiness was different from each other by the groups of pines from eastern and western regions of continents. The difference between them seems to be caused from difference of continentality of the climate. The winter hardiness of pines appears to be more closely related to MTCM than MWI of their native habitats. Thus, it is postulated that very hardy pine species have evolved in highly contipental and winter cold climates.
Sporo-dispersal period of most Pterophyta is limited within one or two months in Hokkaido. Even in the same species, there is a tendency that the spore-dispersal period becomes shorter according to the forwarding in the northern part of Japan Archipelago. Many kinds of summer green ferns disperse spores from late July to September whereas other ferns including evergreen, semi-evergreen and winter green ones from August to early November in Hokkaido. Among sixty Pterophyta species studied in Hokkaido, about forty species them disperse spores during the limited period, from the end of August to early September. These characteristics of spore-dispersal might be caused by the restriction of growing season in the cold climates. Moreover, many kinds of ferns which disperse spores at the end or August, usually grow into young gametophytes in early winter. This also suggests that the gametophytes should live in winter as thalli and wait for the alternation of generation into sporophytes until the coming spring and summer. These phenomena are regarded as one of the adaptive strategies in the carly life history of gametophytic generation for over wintering of Pterophyta in the cold climates in Japan Archipelago.
Several soils from the Tama basin were acclimated at 25℃ in air-tight vessels until the constant rates of CO_2 evolution were obtained. The rate Y (mg C/kg dry soil/hr) of CO_2 evolution from the acclimated soils were highly correlated with the amount X (mg C/kg dry soil) of dissolved organic carbon in soil solution obtained by a centrifugalization. The equation Y=0.381X obtained in the acclimated solis held almost equally well in the treated soils by an air-drying, heating or others. The results were aldo compared with some soils from different sources in Japan.
To analyze the mechanism of establishment and succession of the intertidal flat community, eight types of column designed to produce the artificial disturbance against some environmental conditions were buried in a brakish intertidal flat. The interaction between the change of water and/or bottom environment and the settlement of community was pursued. It was revealed that the establishment and distribution of some characteristric benthic and sessile invertebrates closely interacted with some water qualities such as dissolved oxygen, water velocity and rate of passing water through the bottom, as well as the bottom qualities such as the thickness of deposit, Eh potentials, total carbon and nitrogen contents.