YODA, Kyoji and KIRA, Tatuo (Dep. Biol., Fac. Sci., Osaka City Univ., Osaka). 1982. Accumulation of organic matter, carbon, nitrogen and other nutrient elements in the soils of a lowland rainforest at Pasoh, Peninsular Malaysia. Jap. J. Ecol., 32 : 275-291. The accumulation of organic matter, C, N, P and exchangeable bases in soil was studied at eight sites in the IBP/PT Study Area in Pasoh Forest Reserve, Negeri Sembilan, Penisular Malaysia. The organic matter accmulation in A_0-layer and mineral soil (1m deep layer) amounted to ca. 50t ha^<-1> and 120t ha^<-1>, respectively. Big wood litter over 10 cm in diameter accounted for about 1/3 of the total orgainic matter accumulation. These corresponded to ca. 25 t ha^<-1> (A_0-layer) and 60-81 t ha^<-1> (mineral soil) of total carbon. The inventory of the other elements were : 5-10 t ha^<-1> of N, 32-35 kg ha^<-1> of P (soluble in 0.2N HCl), 94-340 kg ha^<-1> of Ca, 66-155kg ha^<-1> of Mg, 331-481 kg ha^<-1> of K, and 150-265 kg ha^<-1> of Na. Their concentration decreased more or less exponentially with increasing soil depth with the exception of Ca and Na. The amount of storage and estimated turnover rate of soil nutrients were compared with those in other tropical forests with discussions.
MATSUDA, Kozue (Dep. Biol., Fac. Sci., Tokyo Metropolitan Univ., Tokyo). 1982. Studies on the early phase of the regeneration of a konara oak (Quercus serrata THUNB.) secondary forest. I. Development and premature abscissions of konara oak acorns. Jap. J. Ecol., 32 : 293-302. Premature abscissions of konara oak (Quercus serrata THUNB.) were studied in order to obtain a quantitative data on the starting phase of the regeneration processes of a konara oak secondary forest in Mitaka City, Tokyo. Starting from flowers, the number of individuals and the amount of materials lost during the course of fruit production were followed. Of female flowers, in number, only 0.8% became mature fruit in 1979 ; many were aborted without injury in the earlisest developmental stage. In contrast, much material was lost due to subsequent insect attacks. However, insect attacks to fruit in earlier developmental stages were suggested to have an effect of thinning excess fruit with a small amount of material loss, being contrasted with later insect attacks, which cause only a waste of material.
OHNO, Keiichi (Bot. Inst., Hiroshima Univ., Hiroshima). 1982. A phytosociological study of the valley forests in the Chugoku Mountains, southwestern Honshu, Japan. Jap. J. Ecol., 32 : 303-324. Communities of the alliance Pterocaryion rhoifoliae developed in valleys in the cool temperate zone of the Chugoku Mountains were classified into two associations of Pterocarya rhoifolia and an association and one community of Fraxinus platypoda. These communities are distributed differently in the East and the West Chugoku Mountains, which are divided by the Go River basin. This geographical border line of the distributional range was supported by climatic divisions based on the Japan Sea index. Occurrence ratio between the Japan Sea side and the Pacific side elements were calculated in each community. The rate of the Japan Sea side element was generally large in the stands of the Pterocarya rhoifolia communities, but that of the Pacific side element tended to increase in the stands located in the southern parts of the ranges. As a peculiar phenomenon, Fraxinus platypoda communities in which the rate of the Japan Sea side element is comparatively large are developed in the valleys of the Chugoku Mountains.
KANAZAWA, Yoichi (For. & For. Prod. Res. Inst., Ibaraki), 1982. Some analyses of the reproduction process of a Quercus crispula BLUME population in Nikko. I. A record of acorn dispersal and seedling establishment for several years at three natural stands. Jap. J. Ecol., 32 : 325-331. Acorn and cup dispersal of Quercus crispula was measured for 3 or 5 years at three natural stands. The number of dispersed acorns varied either year to year or between stands, ranging from 0.3 to 39.9 per m^2. The number of dispersed acorns was usually about 90% of dispersed cups. The number of established seedlings after experiment was 0.24,0.09 and 0.05 per m^2 at stands A, B and C, respectively. Based on these values, the remaining process from the production to the establishment of acorns or seedlings for 5 years was estimated at stands A and B. According to this estimation, about 15% of produced acorns was eaten or carried away by animals on the tree, and out of the rest only a few developed to seedlings on the forest floor. This decrease of acorns was thought to be owing to predation by animals. Hence, for the successful regeneration of this species, the following conditions seem to be needed ; the sufficient supply of acorns so as to survive despite predation by animals, the removal of upper layers to light up the forest floor, and keeping off the invasion of other plants suppressing the growth of Q. crispula.
YONEDA, Tsuyoshi (Dep. Biol., Fac. Sci., Osaka City Univ., Osaka). 1982. Turnover of live and dead woody organs in forest ecosystems-an assessment based on the changes in the frequency distribution of their diameter (Studies on the rate of decay of wood litter on the forest floor. IV). Jap. J. Ecol., 32 : 333-346. The frequencyφ (d) distribution of wood diameter (d) was determined or estimated in several forest stands of Japan and Malaysia for three different stages : 1) live woody organs in a stand [φ_1 (d)], 2) freshly fallen wood litter [φ_2 (d)], and 3) wood litter accumulating on the forest floor to decay [φ_3 (d)]. The regression of logφ on log d proved to be approximately linear in all the three stages, but the gradient of regression lines differed among the stages. The ratio of φ_1 (d) to φ_2 (d) represented the mean turnover time of live woody organs and was proportional to d^<0.9>. The mean turnover time of accumulating wood litter was similarly given by φ_3 (d)/φ_2 (d), which was proportional to d^<0.2>. A new formulation was developed for estimating the amounts of falling and accumulating wood litter from their maximum diameter to show good applicability to the data from other sources. The 'breakability' of a live branch was found to be proportional to its cross-section area or d^2.
SAWADA, Shinichi, KASAISHI, Yoshihiro & NAKAMURA, Yoichi (Dept. Biol., Fac. Sci., Hirosaki Univ. Hirosaki) 1982. Difference in adaptive strategy of production process between indigenous and naturalized dandelions under artificial distrubance. Jap. J. Ecol., 32 : 347-355. This study focusses on the adaptability of production process of two species of dandelions to artificial disturbance by periodical mowings. One naturalized dandelion, T. officinale and one indigenous one, T. hondoense, were grown separately in an experimental garden. During brief periods between each mowing, T. officinale utilized photosynthate and reserved matter in its roots for reconstruction of leaves, whereas T. hondoense simulataneously distributed the assimilated matter to roots as well as to leaf formation. The latter species retained its newly constructed leaves for a shorter period than the former. The recovery rate of leaf area during the short periods between each mowing was much higher in T. officinale than in T. hondoense. The former species retained an average of more than three shoots per individual throughout the growing season, while the latter showed an almost unchanged value of 1.1. The leaf amount per shoot on T. officinale just before the mowing was almost equal among individuals having various shoot numbers and also similar to that per individual of T. hondoense. Net assimilation rates of the former species were always slightly lower than those of the latter during the main growing period. These differences in production process in reaction to the mowing as a typical artificial disturbance are discussed from the view point of adaptive strategies for the establishment of the two dandelion species.
KAMIO, Akira (Fac. Agr., Yamagata Univ., Tsuruoka). 1982. Studies on the drying of marshy and heavy clay soil ground by means of vegetations-On the process of polder land drainage and structural changes of Phragmites communis community in the Hachirogata Central Polder. Jap. J. Ecol., 32 : 357-364. In the Hachirogata Central Polder, a stage of plant community dominated by Phragmites communis Trin. was observed three or four years after reclamation through various series of initial successions. With continued drainage and further desiccation of the marshy and heavy clay soil ground, dense stands of P. communis gradually changed to sparse stands. Horizontal rhizomes tended to shift downward from the surface layer to the lower layers of the ground as the level of ground-water was lowered year by year. The highest frequency of the horizontal rhizomes was found in an intermediate layer about 10 cm above the gley layer.
SETO, Masayuki (Fac. Agri., Tokyo Univ. of Agri. & Tech., Fuchu, Tokyo) & MISAWA, Kazuhiro (Fac. Agri., Tokyo Univ. of Agri. & Tech., Fuchu, Tokyo). 1982. Growth rate, biomass production and carbon balance of Pseudomonas aeruginosa in a glucose-limited medium at temperature and osmotic pressure extremes. Jap. J. Ecol., 32 : 365-371. The specific growth rate of Pseudomonas aeruginosa was variable with the change in culture temperature or osmotic pressure of the medium, while the effciency of biomass production and the balance of carbon were almost invariable over a wide range of temperature or osmotic pressures. At temperature or osmotic pressure extremes, the efficiency decreased and the amount of respired CO_2 increased, suggesting the occurrence of energy uncoupling between the anabolism and the catabolism. The synergistic effects of both temperature and osmotic pressure were conspicuous reducing the temperature range where the organism could grow.
IZAWA, Masako, DOI, Teruo & ONO, Yuiti (Dep. Biol., Fac. Sci., Kyushu Univ.). 1982. Grouping patterns of feral cats (Felis catus) living on a small island in Japan. Jap. J. Ecol., 32 : 373-382. Range utilization and social relationship of feral cats (Felis catus) were investigated by direct observation and radio-tracking. The range structure of the feral cat in this study also resembled the pathnetwork systems described by HEDIGER. The range of cat was composed of three characteristic components such as a feeding site, resting sites and paths. Each cat used only one feeding site and did not switch it seasonally. The cats utilizing the same feeding site organized "feeding group". Synchronization of feeding activity and overlapping ranges of the members of the same feeding group were observed. These features of feeding group show the amicable relationship among the members. It was considered to result in the adaptation to clumped distribution of abundant food resource.
ONOYAMA, Keiichi & ABE, Takuya (Dept. Zool., Fac. Sci., Kyoto Univ., Kyoto). 1982. Foraging behavior of the harvester ant Messor aciculatus in relation to the amount and distribution of food, Jap. J. Ecol., 32 : 383-393. The foraging behavior of a colony of Messor aciculatus was studied with individual marking under natural and experimental food conditions. Each ant collected seeds of Setaria viridis var. minor on its own defined ground, passing through almost the same and almost straight course. Natural and experimental interruptions revealed strong site tenacity of foragers. When much food was experimentally supplied near the nest, the number of aboveground ants rapidly increased. When there was no food, it decreased to several in a few days but never became zero. These several ants were rather fixed members and probably played the role of scout. When much food was supplied more than 1 m from the nest, only a few ants which found the food carried it repeatedly. Foragers can transmit information about the presence but not the location of food. The foraging behavior of colony is characterized by individual foraging, site tenacity, information transmittion about the presence of food when it is much and near the nest, and the existence of scouts despite there is no food. The foraging system with these characterictics found at the individual and colony levels can efficiently function to any amount and distribution of food.
HAYASE, Nagatoshi (Yamato Junior High School, Ibaraki) & YAMANE, Soichi (Biol. Lab., Fac. Ed., Ibaraki Univ., Ibaraki). 1982. Life history during the aquatic life period of a salamander, Onychodactylus japonicus (HOUTTUYN), at Mts. Tsukuba, Ibaraki, Japan. Jap. J. Ecol., 32 : 395-403. The duration of the aquatic life period (including incubation and larval stages) of Onychodactylus japonicus is estimated to be 3 years and 2 to 5 months, based on analyses of age group structures and morphological and ecological observations. Eggs are supposed to be laid at head waters between early and late May and hatch between August and October. Hatchlings seem to stay there for several months, then migrate downstream and begin to feed. They land on in the fourth summer, after metamorphosis into subadults (terrestrial form) when the body length (including tail) has reached about 8 cm. Survival rate during the aquatic life period, except just after hatching is nearly constant at about 50% per year.
TSUKADA, Matsuo (Dept. Bot., Univ. Wash., Seattle, WA 98195 U.S.A.). 1982. Pollen deposition of Alnus rubra Bong. Jap. J. Ecol., 32 : 405-414. Total pollen deposition of Alnus rubra was 5,114 grains per cm^2 at College Hill (47°35′32″N lat., 122°09′09″W long.; alt. 91m), Bellevue, Washington, during the 1975 maximum flowering period (March 23-30). The amount of Alnus pollen deposition on each phenological day (11 : 00-11 : 00) was proportional to the hourly cumulative temperature between 11 : 00 and 15 : 00 hours (r=0.964). During this period, the pollen deposition rose steeply from 6.0±4.0 to 34.4±33.0 (gr cm^<-2> hr^<-1>). Two depositional peaks, 23.3±22.8 (5 : 00-6 : 00) and 42.6±41.6 (16 : 00-17 : 00), were also observed ; in the former case pollen emitted mostly on the preceding day was probably brought down by the descending wet airmass, and in the latter, it was deposited from near-surface (probably below 50 m high) by gradually descending air. Thus, the daily descending air should prevent long distance transportation of Alnus pollen. Taking theoretical analysis of pollen dispersal into the air into account, this fact suggests that the majority of the pollen deposits within a radius of 2.0 km. Out of the total Alnus pollen deposited at the site, about one half (2,435 gr cm^<-2>) were forced to settle on the ground by rains which have the effect to even pollen concentration in a wide region.
KANDA, Fusayuki (Biol. Lab., Kushiro Coll., Hokkaido Univ. Educ., Kushiro) & SATO, Ken (Biol. Lab., Fac. Gen. Educ., Hokkai Gakuen Univ., Sapporo). 1982. Composition and density of Dictyostelid cellular slime molds in different plant communities formed along altitude of Mt. O-Akan, Hokkaido. Jap. J. Ecol., 32 : 415-425. The occurrence and distribution of Dictyostelid cellular slime molds were studied by means of a clonalisolation technique in relation to altitude of Mount O-Akan which contains alpine communities. Sixteen sites were sampled at elevations between 420m and 1350m. Eight species of cellular slime molds were isolated from the soil samples of thirteen sites. In this study, absolute densities, relative densities and frequencies of the cellular slime molds at each collecting site were calculated. The absolute density of cellular slime molds decreased as the altitude incleased in Mt. O-Akan. This result indicates a climatic influence on the distribution of cellular slime molds.