SETO, Masayuki and Tadayoshi TAZAKI (Dept. Plant Protection, Fac. Agri., Tokyo Univ. of Agri. and Tech.) Carbon dynamics in the food chain system of glucose-Esclerichia coli-Tetrahymena vorax. Jap. J. Ecol. 21,179-188 (1971) Applying the food chain system of organic compound (glucose), bacterium (Escherichia coli) and protozoa (Tetrahymena vorax) as a representative free-swimming unicellular predator, the carbon balance and the yield efficiency of the protozoa were studied, laying stress upon the dynamics of carbon from the ecological point of view. When the protozoa was cultured monoxenically in the medium in which washed suspension of E.coli was the sole source of carbon, the formation of the protozoa, evolution of CO_2 and excretion of the waste products increased as the substrate bacterium decreased, and at the time when the growth of protozoan population just reached the stationary phase, the efficiency of yield of the protozoa to the decrease of the bacteria, together with the evolution of CO_2 and the excretion of the waste products (particulate, soluble) were, respectively, 0.2,0.3 and 0.5 (0.3,0.2), in terms of carbon. From the growth curve of T.vorax and the decrease of E.coli, it was estimated that for formation of a new cell of the protozoa, ca.4×10^4 cells of the bacteria were ingested. The growth rate of T.vorax at the exponential phase feeding upon E.coli was 0.40 hr^<-1>, with the generation time of 2.50 hrs., under aerobic condition at 25℃. At different initial concentration of the bacterium (10-250 ppm-C), the growth curves of the protozoa showed the same type and the growth rate (0.40 hr^<-1>), and differed only in final yield proportionally, i.e., the efficiency of the yield of the protozoa-C (0.2) to the decrease of the bacteria-C and the evolution of CO_3-C (0.3), together with the excretion of the waste products-C (0.5), were almost the same irrespective of the different concentration of the bacterium ; but at the lowest bacterial concentration (2.5 ppm-C) slight inhibition both in the growth rate and in the yield efficiency was noted. Further, the numbers of the bacterial cells remained in the medium at the stationary phase of the protozoan growth were almost the same irrespective of the difference of the initial concentrations of the bacterium (4.2×10^7-4.2×10^9 cells/ml.) and showed ca. 1.8×10^7 cel1s/ml. It seems probable that T.vorax has no ability to ingest the bacterium less than the order of 10^7 cells per ml. Different culture temperature (17-28℃) did not affect the carbon balance, and altered only the growth rate (0.18 hr^<-1> at 17℃, 0.40 at 25℃ and 0.44 at 28℃). At the highest culture temperature (33℃) no growth occurred. The rate of CO_2-C evolution per unit biomass-C of T.vorax per hour at the exponential phase was estimated to be 0.2. As the biogeochemical agent, the role of the bacterial and protozoan populations in the turnover of material and mineralization of organic compounds were also discussed by a diagram of carbon flow for the relevant food chain system.
M.S.MURTHY (Department of BioSciences Saurashtra University) Ecology of upper catchment area of River Narmada climo-vegetational relationships-I. Jap. J. Ecol. 21,188-192 (1971) Aiming at flood control and soil erosion via afforestation, for the first time in India, a scheme on ecology of the upper catchment area of River Narmada has been taken up under the sponsorship of the Council of Scientific and Industrial Research, Government of India, and is being execnted in four phases. The present series of papers pertains to Phase-I of the project viz., phytosociological survey of the forest vegetation from the source of the river at Amarkantak upto Jabalpur. The area covers a linear distance of about 310 km and an approximate area of about 20,407 sq km. Of this total area, the investigations presented here cover an approximate area of about 7,310 sq km (From Manot to Jabalpur). The meteorological data available has been computed as per the system of THORNTH-WAITE (1955) to arrive at figures of water balance. This has enabled to distinguish four eco-climatic zones, with varying climatic indices. Growth and distribution of different forest trees have been observed to behave differently in the different eco-climatic zones distinguished and in relation to topography also. A study of correlation of the existing forest vegetation in the different four eco-climatic zones is the subject of the current series of papers.
NAITO, Toshihiko, IWANAMI, Yuuki and Shigeru IIZUMI (Toboku Univ., Sendai) Effects of fire on vegetation of Thujopsis dolabrata var. hondae forest on a hill, Odagawayama, Aomori Prefecture. Jap. J. Ecol. 21,192-197 (1971) The forest dominated by Thujopsis dolabrata var. hondae of about 145 years and situated on the hill. Odagawayama, about 15 km northwest of Aomori city, was burnt on June 2,1967. Before the fire, the forest remained undisturbed, so that the forest floor was covered by a thick layer of dead twings and leaves of about 800 g dry weight per square mater. The forest floor plant communities were compared between the burnt and unburnt forests. The following species markedly increased in coverage after the fire : Aralia slata, Prunus grayana, Rubus cratasgifolius, Rhus japonica, Magnolia abovata, Vitis coignstias, Clorodendrond trichotomum. Miscanthus sinensis, Erigaron bonarionsis and Lactuca indica. The buried-seed populations in the ground of the Thujopsis dolabrata var. hondas forest is detected by the K_2CO_2 method (AWANO and IIZUMI). The species detected amounnted to eleven including Viola grypossvas. Rubus oratasgifolius and Aralia slata etc. Moreover, the seedlings of those species were seen on the forest floor after the fire. To estimate the possible high tempertures of the tree layer during the fire, a burning test with the Thujopsis dolabrata var. hondae leaves was carried out in the laboratory. Thujopsis dolabrata var, hondae leaves are charred in 6 min. at 150℃, and the leaves ignited in one min. at 350℃. It is probable that remarkably high tempertures were caused by the canopy fire in the present study.
OKAMOTO, Kiku, (Entomol. Lab., Kyoto Univ. Kyoto) The reproduction curve of host in host-parasite interacting system and parasite free system. Jap. J. Ecol. 21,197-203 (1971) Using the azuki bean weevil, Callosobruchus chinensis (L) and its larval parasite, Anisopteromalus calandrae (Howard), the population fluctuation in host-parasite interacting systems and that in parasite free systems were examined under the physical condition of 30℃ and 70% R.H.. Strictly constant quantity of larval food was supplied to each generation. In the parasite free systems, the host populations maintained nearly constant levels of their density (Fig.1), and the reproduction curves of saturation type were obtained from these population fluctuation (Fig.2). Besides the relation between parental density and progeny density in particular generations, was examined and mountainshaped reproduction curves were obtained as shown in Fig.3. Rather concentrated age distribution and narrow spaces of experimental cages may have been responsible for the appearance of this type or reproduction curve. In the host-parasite interacting systems, the relationship between the final host density in a given generation and the initial host density in the next generation was represented by a saturation curve. As the initial host density, it is resonable to use the sum of the numbers of emerged hosts, parasites and further dead corpses of the host in the beans. Thus, the reproduction curve of the azuki bean weevil was fundamentally regarded as a saturation type in the populations of both the parasite free systems and the host-parasite interacting systems.
YAJIMA, Takaaki, Shoichi, YOSHIDA and Takao, WATANABE (Biological Institute, Tohoku University, Sendai) Ecological studies on the population of adult mosquito, Culex tritasniorhynchus summorosus Dyar : The diurnal activity in relation to the physiological age. Jap. J. Ecol. 21,204-214 (1971) The diurnal activity of a mosquito, Culex tritasniorhynchus summorosus, was studied in relation to the physiological ages. With two dry ice baited traps (DA and DB) and a pig baited trap (PIG), the sampling was continued for four weeks, July 25 to 31,August 22 to 28,September 5 to 11 and 19 to 25 in Natori City, Miyagi Prefecture in 1966. Most of the ovarian stages of the females were Ib and the copulation rate was near 100 per cent. The monoparous females occupied about 90 per cent among the parous ones. The parous rate in the later half of the night was significantly higher than that in the earlier half of the night in the PIG population. But in the DA and DB populations there was no significant difference. The nulliparous females of the PIG, and DA and DB populations showed a tendency to appear in the earlier half of the night, but those of the PIG were more distinguished. In the nulliparous females of the PIG, and the DA and DB populations, the "Young" females tend to appear later than the "Old" ones. And the "Youngs" appeared more abundantly in the evening in the DA and DB populations, but in the morning in the PIG population. Such tendencies were recognized even in the monoparous ones. In the monoparous females, although A (sac like stage) appeared later than C (dilatation stage) in the night in both populations, A of the PIG bad a tendency to be shifted to the later half of the night than those of the DA and DB. As the diurnal activity pattern of B (half contraction stage and the transitional one between A and C) of the PIG, and DA and DB populations, was similar to those of A and C respectively, it is considered that the monoparous females of the DA and DB populations is younger than those of the PIG.
HAYASHI, Ichiroku (Sugadaira Biol. Lab. of Tokyo Kyoiku Univ.) Phenology of grassland species at Sugadaira, Central Japan. Jap. J. Ecol. 21,214-221 (1971) The flowering times of 100 grassland species were observed at Sugadaira in 1968. At the same time, the growth forms of these species were examined and the relationship between the growth form and the flowering time was discussed. Most species flowering in spring belong to b, t and r types of Numata's system of classification. On the other hand e type is abundant in species whose flower initiation occur in August and September. According to the data, there is close relationship between the flowering time and the growth form. This fact suggests that the seeds ripend in spring and early summer, and in late summer and autumn may be made of the matter assimilated last, and in the current growing season, respectively. The characteristics of the life cycle of grassland species, including the flowering time, are under discussion in term of the growth form or distribution of the matter assimilated to the organ of the plant.
CHIBA, Yoshihiko (Biological Institute, Yamaguchi University, Yamaguchi) Phase angle relationship between the circadian activity of the mosquito, Aedes flavopictus, and 24 hr LD cycles. Jap. J. Ecol. 21,221-226 (1971) The circadian activity of the mosquito Aedes flavopictus was assayed under 24 hr LD cycles of different L : D ratios. Under the shortest photoperiod (LD 4 : 20), the major peak of activity started just before the onset of darkness (dusk). But as the photoperiod was lengthened, the major peak began earlier and earlier than dusk. In addition such advance of the major peak from dusk occurred in the same direction as a shift of the onset of light(dawn). A possible explanation for this is that the times of both dusk and dawn combinationally determine the time of the onset of the major peak.
L.N.VYAS, R.K.GARG and M.P.S.RANAWAT (Dept. of Botany, School of Basic Sciences and Humanities. University of Udaipur and Dept. of Biology, Lambardar Higher Secondary School, Udaipur) Observations on the dry matter production in Mitragyna parvifolia Korth. Jap. J. Ecol. 21,227-230 (1971) Estimation of dry matter production in Mitragyna parvifolia Korth is presented. The area of study, Borimalan block in the Prasad range, is 54 kms south of Udaipur town (24°11'N and 73°42'E). From the study it is concluded that : - (i) The girth (G), branch dry weight (BDW), tree height (Th), total plant biomass and photosynthetic area increase with an increase in the number of growth rings (x). The regression equations obtained are-G=-34.81+2.674x (for bole), G=-1.416+2.4x (for branches), BDW=-14.00+2.37x, Th=-0.65+0.328x. (ii) The net above ground biomass production in this tree species varies between 659-3424 kg/ha. (iii) The average increment in non-photosynthetic above ground biomass ranges from 1.5 kg/tree/yr. to 8.85 kg/tree/yr. The increase is gradual up to 30 growth rings, followed by a sudden rise from 30-35 growth rings and a decline afterwards.
KIRITA, Hiromitsu (Dept. Biol., Fac. Sci., Osaka City Univ., Osaka) Studies of soil respiration in warm-temperate evergreen broadleaf forests of southwestern Japan. Jap. J. Ecol. 21,230-244 (1971) Daily rates of soil respiration were measured periodically through the year by the 'sponge method' (KIRITA 1971) in two evergreen oak forests, the climax vegetation of warm-temperate Japan. No daily rhythm was recognized in CO_2 evoluntion from the forest floor, while the soil respiration rate (SR) showed a marked annual cycle closely following the seasonal change in soil surface temperature (t). The temperature dependency could be approximated by SR=β exp (at), in which a was nearly constant in all stands at 0.105/℃. The annual rates of soil respiration ranged between 3.4 and 4.6 kgCO_2/m^2・yr or 0.92-1.25 kgC/m^2・yr, and were 2.5-4.0 times as large as the rate of dead organic matter supply to the soil as litterfall (0.54-0.80 kg/m^2・yr or 0.27-0.40 kgC/m^2・yr). It was suggested that the carbon budget in the soil-vegetation systems was nearly balanced if the respiration and turnover of the roots were taken into consideration. The transport and turnover of CO_2 in the soil air were also briefly discussed.
L.N.VYAS, R.K.GARG, M.P.S.RANAWAT and R.R.DAS (Dept. of Botany, School of Basic Sciences & Humanities, University of Udaipur and School of Studies in Botany, Vikram University) Method for estimation of biomass and rate of production in a tropical tree.Jap.J.Ecol. 21,244-246 (1971) The present communication incorporates the data on biomass production by A dina cordifolia growing in deciduous forests of south Rajasthan (India). Methods for the computation of the biomass and age from the number of growth rings are discussed.
IWANAMI, Yuuki (Institute for Agricultural Research, Tohoku Univ.) Burning temperatures of grasslands in Japan. (3) Condition of fuel before and after burning in grasslands.Jap.J.Ecol. 21,246-254 (1971) Described are the condition of fuel before and after burning in grasslands situated in the suburbs of Sendai (Kawatabi, south Zao, Sakunami and so on). In the Zoysia type, Miscanthus type and Sasa type grasslands, the amount of fuel before burning was 0.2-0.6,0.25-1 and 1-3 kg/m^2,respectively. In the Miscanthus type grassland, according to whether the dead grass is lying on the ground by the accumulated snow, the type of vertical distribution of the fuel can be classified into two classes, i.e. (1) "Standing dead type" and (2) "Push down type". The disposition of fuel of the Zoysia type grassland belongs to the "Push down type", and that of the Sasa type grassland to the "Standing dead type". In the field fire or burning, it is necessary that the water content in the fuel is low for the fuel to burn well. Generally speaking, the standing dead of Miscanthus burnt well when the water content was less than about 50 per cent. However, that of the "Push down type" sometimes failed to be burnt even when the water content was less than 30 per cent, because evaporation from the fuel was difficult. In the Miscanthus type and the Sasa type grasslands, it was easy to burn 90 per cent or more of the entire fuel. On the other hand, in the Zoysia type grassland, even when it seemed to be burnt quite well, 35-73 per cent of the fuel amount was left unburnt.
GOTO, Miyako and Tadashi GOTO (Seki High School and Asahigaoka Lower High School, Seki City, Gifu Pref.) Fish fauna in River Nagaragawa and its change for the last several years in relation to river pollution. Jap.J.Ecol. 21,254-264 (1971) Fish fauna were investigated quantitatively in the middle reaches of the Nagaragawa River, Gifu Prefecture, from May 1967 to August 1971,by using a small weir-trap "Noboriochi". As the result 1 species of lamprey and 35 species of actinopterygian fishes were recorded. The number of fishes collected changed remarkably from year to year. Among the ten species of dominant fishes, the number of a goby (Rhinogobius flumineus), a loach (Niwaella delicata), chubs (Zacco platypus, Z.temmincki), a gudgeon (Psedogobio esocinus) and a bullhead (Liobagrus reini) decreased while a certain loach (Cobitis biwae) rather increased, but a gudgeon (Gnathopogon elongatus) and a dace (Tribolodon hakonensis) did not change in quantity during the years. The fish fauna and their populations were much different and remarkably lower compared with that of ten years before. Their change and difference may be caused not only by the change of environmental conditions in the river estuary affecting anadromous and amphidromous fishes but also by the effect of the pollution by the effluents of the pulp and paper mills.