bluuebunny/crossref_metadata_2025_split huggingface dataset:
Systems analysis of density‐dependent population processes in the azuki bean weevil, Callosobruchus chinensis
Authors: Shimada Masakazu 
Published: March 2006

AbstractSystems analysis of density‐dependent population processes was conducted in an experimental population of the azuki bean weevil, Callosobruchus chinensis. Density‐dependent population change was formulated for two separate processes; adult production of eggs and hatching of the eggs outside the beans, and survival of the first instar larvae inside the beans and their emergence as new adults. The formulation of each process was based on a common basic equation modified from the logistic‐difference equation. Parametric values were estimated from experimental data on C. chinensis in a laboratory population.Simulations of the model showed good fits not only to observed population changes both outside and inside the beans, but also to the observed reproduction curve reflecting the population change as a whole within one generation in an experimental population.Furthermore, population dynamics from generation to generation were simulated from the model reproduction curve. The simulation showed a slight dumped oscillation and converged to a carrying capacity, which fitted well with the experimental population dynamics.
Growth and biomass turnover of Hydrocharis dubia L. cultured under different nutrient conditions
Authors: Tsuchiya Takayoshi 
Published: March 2006

AbstractGrowth of a floating‐leaved plant, Hydrocharis dubia L., was examined under varying nutrient conditions between 0.3 and 30 mgN l−1 total inorganic nitrogen. H. dubia plants cultured under the most nutrient‐rich condition showed the highest maximum ramet density (736 m−2), the highest maximum biomass (80.4 g dry weight m−2), and the highest total net production (185 g dry weight m−2 in 82 days). Plants under nutrient‐poor conditions had a relatively large proportion of root biomass and a small proportion of leaves with a long life span.Compared with other floating‐leaved and terrestrial plants, the maximum biomass of H. dubia was relatively small. This, and the rapid biomass turnover, was related to the short life span of leaves (13.2–18.7 days) and large biomass distribution to leaves.
Buried seed populations on the volcano Mt. Usu, northern Japan, ten years after the 1977–78 eruptions
Authors: Tsuyuzaki Shiro 
Published: March 2006

AbstractIn 1987, a study on buried seed populations was conducted in the crater basin of Mt. Usu, a volcano located in northern Japan, where the vegetation had beeen almost completely destroyed by eruptions in 1977 and 1978. The former vegetation had consisted of grassland and broad‐leaved forest. In the areas formerly occupied by this grassland and forest, 2128.0 and 1985.3 seeds per square meter, respectively, were extracted from 12 blocks of the former topsoil using a floattion method. This revealed that many seeds were still viable even after ten years of burial under thick volcanic deposits. The seeds were distributed more in sandy soil than in rocky soil of the former topsoil. Twenty‐five species, most of which favored grassland, were detected in both the former grassland and forest. From comparison of α‐and β‐diversities between the grassland and forest, the structure of the buried seed population was considered likely to have been more diverse in the forest than in the grassland. The determinants of composition of the buried seed populations were discussed with reference to the former vegetation and soil characteristics.
Ecological studies on the plants of fagaceae V. Growth in the sapling stage and minimal participation of reserve materials in the formation of annual new shoots of the evergreen Quercus glauca thunb
Authors: Matsubara Teruo , Hiroki Shozo 
Published: March 2006

AbstractThe growth in the sapling stage and participation of reserve materials in the formation of annual new shoots were studied in the evergreen tree Quercus glauca. The growth and some allometric relationship were analyzed for 1‐to 4‐year‐old Q. glauca plants. Each individual was felled at the foot, or all the leaves were removed at the end of the growth season (December). Sprouts were formed on the remaining stump and new shoots were formed from winter buds under dark or light conditions. The dry weight of each plant part was measured before and afte,, the formation of these new shoots. The amount of reserve materials in each plant part was estimated from the difference in allometric relatationships before and after the formation of new shoots. Although the results showed that a small amount of reserve material existed in roots, the participation of reserve materials in the formation of annual new shoots was negligible in Q. glauca growing under usual conditions, and substrates for the formation of new shoots were derived from the products of photosynthesis in old leaves and developing new leaves. Some of the growth characteristics of Q. glauca were compared with those of the deciduous species Quercus variabilis to explain ecological behavior of the two species in warmtemperate secondary forests.
Effect of light interception by non‐photosynthetic organs on canopy photosynthetic production
Authors: Kurachi Nahoko , Hagihara Akio , Hozumi Kazuo 
Published: March 2006

AbstractA canopy photosynthesis model was derived on the assumption that the light diminution within a canopy is caused by both leaves and non‐photosynthetic organs. The light diminution by leaves and that by non‐photosynthetic organs were taken into account separately in the Lambert‐Beer equation of light extinction. The light flux density on the leaf surface at each depth was evaluated from the leaf's share of light. The light flux density on the leaf surface thus obtained was incorporated into the Monsi‐Saeki model of canopy photosynthesis. The proposed model was applied for estimating gross canopy photosynthesis in a 19‐year‐old Larix leptolepis plantation where 38% of the light diminution was due to non‐photosynthetic organs. The daily canopy photosynthesis on one summer day calculated using the present model was about 22% less than that calculated by the conventional Monsi‐Saeki model, in which light interception by non‐photosynthetic organs is neglected. The degree of such reduction in canopy photosynthesis through shading by non‐photosynthetic organs was assessed in relation to parameters affecting light extinction, leaf photosynthetic characteristics, and light regime above the canopy.
Food preferences and nematode parasitism in mycophagous Drosophila
Authors: Kimura Masahito T. , Toda Masanori J. 
Published: March 2006

AbstractFood preferences and nematode parasitism were studied in natural populations of mycophagous Drosophila in and near Sapporo, northern Japan. Species which preferred fresh mushrooms showed species‐specific responses to Pleurotus mushrooms:D. pirka bred only on Pleurotus cornucopiae, D. trivitata on P. cornucopiae and P. ostreatus, D. trilineata on these two Pleurotus mushrooms and some other mushrooms, while D. sexvittata bred on a wide variety of mushrooms but seldom on Pleurotus mushrooms. Species which preferred decayed mushrooms (D. quadrivittata, D. histrioides, D. testacea and species of the quinaria species‐group) showed host preferences different from those of the above species. The rate of parasitism by nematodes was generally higher in species which prefer decayed mushrooms than in species which prefer fresh mushrooms. Among species which prefer fresh mushrooms, only D. trilineata was parasitized frequently by nematodes. It was not clear what factors determine the rate of parasitism in these mycophagous Drosophila.D. pirka, D. trivittata and D. trilineata passed through three or four generations per year and entered reproductive diapause in early September in and near Sapporo.
An ecological study of soils in the highlands of western Tibet II. Vertical change from 3900 m to 5450 m in elevation
Authors: Iwatsubo Goro , Zheng Xilan , Shidei Tsunahide 
Published: March 2006

AbstractsTwo kinds of soil study were carried out in the south‐western Tibet region of China. Changes in soil properties with elevation were examined from the snout of a glacier at 5450 m above sea level down to a village (Burang) at 3900 m. The area close to the glacier was devoid of vegetation, probably because of the coldness. With a decrease in elevation, the landscape changed from desert to sparse Artemisia steppe, and below 4750 m, to a thorn‐bush steppe dominated by Caragana spp. which continued down to the village (where the annual precipitation was 169 mm). Organic C, total N and cation exchange capacity (CEC) all increased with decreasing elevation down to 4700 m due to the increase in warmth, but the parameters decreased below 4700 m, reflecting the increase in aridity. Almost no carbonate was detected in areas above 4700 m, but below this elevation it increased exponentially, also reflecting the increase of aridity. Available P tended to decrease with both the decrease in elevation and the increase in carbonate.The vertical distribution of soil parameters was investigated in the soil profiles of dry and wet plots at 4700 m. Organic C, total N, and CEC decreased with increasing soil depth. Their values were higher in the dry plot than in the wet plot. In the dry plot, carbonate increased with depth. Total P was found to be similar in both the wet and dry plots, but there was less available P in the soil of the dry plot, reflecting the abundance of calcium carbonate.
Development of ecology in Japan, with special reference to the role of Kinji Imanishi
Authors: Itô Yosiaki 
Published: March 2006

AbstractThe development of ecology in Japan, especially after the Meiji Restoration (1868), is briefly reviewed. Pioneering studies of Hiratsuka, on the calorimetric budget of a silkworm population, and Motomura, on the relation between numbers of species and individuals in biotic communities, are noteworthy. A critical examination of his role in ecology in Japan reveals Kinji Imanishi to have played pivotal roles in leading Japanese population ecologists to realize the importance of dispersal in population regulation, and leading to the worldwide revival of field primatology. Although Imanishi's later (popular) writings, in which he completely negated the role of competion and natural selection, have justifiably drawn much criticism, his earlier critique of the competition‐Almighty paradigms may be re‐evaluated in the light of recent discussions on interspecific competition and community equilibrium.
Forest ecosystems of east and southeast Asia in a global perspective
Authors: Kira Tatuo 
Published: March 2006

AbstractOwing to the influence of the Tibeto‐Himalayan Highland, the east‐and southeastcoastal zone of the Asian continent lacks the subtropical dry belt, which elsewhere in the world separates temperate forest areas from the humid tropics. Thus forest climates with sufficient rainfall cover coastal areas of the Western Pacific from subarctic eastern Siberia to equatorial SE Asia, giving rise to a sequence of five forest formations. The warmtemperate evergreen (lucidophyll) forest formation is peculiar to this region and represents the east‐coast counterpart of Mediterranean sclerophyll forest, which develops under the west‐coast climate with a different pattern of seasonal rainfall distribution.The characteristics of the five formations and their latitudinal distribution were briefly described as being related to climatic environments. Certain ecosystem properties such as floristic diversity and the rate of organic matter decomposition were found to be very sensitive to thermal gradients, whereas the responses of plant biomass, primary productivity, etc. to changes in thermal climate were less apparent.
Gap characteristics and gap regeneration in a subalpine coniferous forest on Mt Ontake, central Honshu, Japan
Authors: Yamamoto Shin‐Ichi 
Published: March 2006

AbstractGap characteristics and gap regeneration were studied in three mature stands belonging to different community types in a subalpine coniferous forest on Mt Ontake, central Honshu, Japan. Gap disturbance regimes were remarkably similar among stands studied; percentage gap area to surveyed area, gap density and mean gap size were 7.3–8.5%, 17.8–20.0 ha−1 and 40.8–42.5 m2, respectively. The gap size class distributions were also similar and showed a strong positive skewness with a few large and many small gaps; gaps <40m2 were most frequent and gaps >200m2 were rare. Forty‐five to 66% of gaps were due to the death of single canopy trees. Canopy trees more often died leaving standing dead wood (40–5.7%) or broken trunks (43–49%). Shade tolerant Abies mariesii and Abies veitchii, frequently, and Tsuga diversifolia, less frequently, regenerated in gaps, from advance regenerations recruited before gap formation. Picea jezoensis var. hondoensis may regenerate in gaps, from new individuals recruited after gap formation. The breakage of dense Sasa coverage and the mineral soils exposed by the uprooted plants that form gaps might provide regeneration opportunities for shade intolerant Betula. Of the important species limited to the ridge site, Chamaecyparis obtusa, frequently, and Thuja standishii, infrequently, regenerated from plants already in situ. Regeneration of Pinus parviflora was not seen. Based on the gap characteristics and gap regeneration behaviour of each species described, stand dynamics in each stand are discussed.
Temporal changes in food resources, parental feeding and breeding success of Heron Island silvereyes, Zosterops lateralis chlorocephala
Authors: Eguchi Kazuhiro 
Published: March 2006

AbstractThe influences of the temporal change in food supply on the parental feeding effort and breeding success of silvereyes, Zosterops lateralis chlorocephala, was investigated on Heron Island, Australia. Food supply (arthropods and figs) declined as the breeding season progressed. The parental feeding rate and growth of nestlings were lower when food supply was poor. When available, dominant pairs fed their young more figs and fewer arthropods than lower ranking pairs. Dominant pairs raised heavier young than lower ranking pairs when food supply was poor, while there were no significant differences between them when food supply was rich. When food supply was rich, pairs delivering greater amounts of arthropods reared nestlings better, whereas feeding more figs did not improve growth of nestlings. When food supply was poor, pairs spending a longer time at the nest reared nestlings better.
The effect of missing rings on stand‐age estimation of even‐aged forests in northern Hokkaido, Japan
Authors: Takaoka Sadao 
Published: March 2006

AbstractThe effectiveness of estimating stand age from increment core samples taken at stump height (20 cm above ground) was tested in an even‐aged stand of Betula ermanii that had regenerated after a forest fire in 1945 in Hokkaido, Japan. Careful cross‐dating revealed that annual rings were missing in 11 cores out of a total of 42 cores sampled, and that all these missing rings occurred in the outermost part of the core. These facts indicate that precaution has to be taken in selecting trees from which cores are to be sampled. The present work also revealed that those trees with missing rings have a characteristic appearance, with a thinner stem and less crown foliage than normal trees with complete rings. It was also found that even if this appearance test failed, the possibility of missing rings could be detected from a declining growth pattern, with extremely narrow rings on the increment core which normal trees did not show.
Myrmecochorous adaptations of Corydalis species (Papaveraceae) in southern Japan
Authors: Nakanishi Hiroki 
Published: March 2006

AbstractDispersal morphology based on the myrmecochorous adaptations for predator avoidance of seven Corydalis species including two varieties are investigated in southern Japan. Three types of myrmecochory were distinguished: myrmecochory with autochory (diplochory), the explosive ejection of seeds followed by ant transportation; myrmecochory with vegetative reproduction, seed‐transportation by ants and reproduction by tuber; and pure myrmecochory, seed‐transporting by ants only. Diplochory occurs in one winter annual plant, which has explosive capsules, a smooth seed surface, a small elaiosome, long pedicels and large bracts. Myrmecochory with vegetative reproduction occurs in two perennials that reproduce by tuber, although they also produce a small number of seeds with a medium‐sized elaiosome. the pedicels and bracts are medium in size. Pure myrmecochory occurs in five annuals or biennials that are characterized by a rough seed surface with a large elaiosome, comparatively high seed production, short pedicels and only small bracts. Diplochory is exhibited by only one species distributed widely throughout Japan. Myrmecochory with vegetative reproduction is exhibited by species mainly distributed in cool‐temperate northern Japan, while true myrmecochory is exhibited by the majority of Corydalis species in warm‐temperate Japan.
Phytosociological study on natural summer‐green forests in Korea
Authors: Takeda Yoshiaki , Nakanishi Satoshi , Choe Dumun 
Published: March 2006

AbstractTwo phytosociological associations, Corylo‐Quercetum mongolicae and Lespedezo‐Quercetum serratae, were recognized as natural summer‐green forests in the cool‐temperate zone of Korea. They belong to the alliance, Rhododendro‐Quercion mongolicae and Lespedezo‐Quercion serratae, respectively. The former alliance occurs in northern areas of the cool‐temperate zone and the latter develops in southern areas. Both alliances belong to the phytosociological ranking order, Acero‐Quercetalia mongolicae. In contrast to Korean cool‐temperate, summer‐green forest associations, the Japanese ones, such as Fagus crenata or Quercus mongolica var. grosseserrata associations, belong to the order, Saso‐Fagetalia crenatae.
Larval survival of the phytophagous ladybird, Epilachna yasutomii (Coleoptera, Coccinellidae), on the blue cohosh, Caulophyllum robustum (Ranunculales, Berberidaceae), grown under different environmental conditions
Authors: Shirai Yoichi 
Published: March 2006

AbstractLarval survival of four local populations of Epilachna yasutomii in the southern part of Nagano Prefecture was evaluated on leaves of blue cohosh, Caulophyllum robustum, growing at two different sites, Takatoh and Nakatachi. Based on larval survival on leaves of Takatoh C. robustum, Takatoh E. Yasutomii was clearly distinguishable from the three populations in the Minami‐Shinano area (Akasawa, Nakatachi and Tenryu). Takatoh E. yasutomii developed successfully to emergence on C. robustum from both sites, while Minami‐Shinano populations showed a very low survival rate when given Takatoh C. robustum. Under controlled plant growth conditions, larval survival of Akasawa E. yasutomii was significantly reduced when given C. robustum leaves, from either site, exposed to direct solar radiation, which suggested that larval survival was influenced by environmental conditions at the growing sites rather than genetic differences between the plant populations. In contrast, Takatoh E. yasutomii developed well on C. robustum leaves from either site exposed to direct solar radiation. Takatoh E. yasutomii appears to have some defensive mechanism that allows it to overcome a substance deterring larval development, which increases in leaves exposed to direct solar radiation.
Spatial and temporal heterogeneity in population dynamics of citrus aphids at a regional scale
Authors: Lapchin Laurent , Guyot Hervé , Brun Pierre 
Published: March 2006

AbstractA quick method of evaluating aphid infestations on young clementine trees is developed. It uses visual abundance classes. This method is used to compare the population dynamics of two aphid species in 11 orchards in Corsica (France). The curves describing the succession of the abundance indices on each sampling tree between April and July are compared using principal component analyses.The first three factorial axes illustrate the intensity, precocity and flatness of the infestation curves. For each species, a significant between‐orchard variability is demonstrated by comparing the mean factorial coordinates of the sampling trees of the different orchards. The validity of such methods for analyzing the demographic strategies of phytophagous and entomophagous insects at a large scale is discussed.
Reproductive ecology of a cleistogamous annual, Impatiens noli‐tangere L., occurring under different environmental conditions
Authors: Masuda Michiko , Yahara Tetsukazu 
Published: March 2006

AbstractDemographic and reproductive schedules were compared among five populations of a cleistogamous annual, Impatients noli‐tangere L., occurring in habitats with contrasting moisture and/or light environments. In all populations, flowering extended for 2–3 months during which light environment and mortality changed. Seasonal patterns of growth and mortality were significantly different among the five populations studied. The beginning and duration of flowering and the ratio of chasmogamous flowers to cleistogamous ones were also significantly different among populations. An experiment was conducted under different light conditions (open and closed) to separate the genetic and environmental components of the variation in reproductive traits observed among populations of I. noli‐tangere. Transplanted plants showed significant among‐population variation in flowering time, as is observed in natural populations, suggesting genetic differentiation among populations of this species. On the other hand, the ratio of chasmogamous flowers did not differ among plants transplanted from three populations. Based on these results, the authors suggest that facultative cleistogamy is a conditional strategy under seasonally changing environments.
A simple model of interactive pollutants
Authors: Yeung David W. K. 
Published: March 2006

AbstractThis study presents a model of two interactive pollutants in which the natural rate of regeneration of each pollutant is affected by the quantity of the other pollutant present in the atmosphere. The behavior of pollution accumulations in the natural unintervened system is characterized. With human intervention, it is shown that while a sustainable environment can be obtained, a deteriorating environment may also arise. There is a unique continuous boundary beyond which the environment is non‐revitalizable.
Effects of Sika deer on the regeneration of a Fagus crenata forest on Kinkazan Island, northern Japan
Authors: Takatsuki Seiki , Gorai Takuji 
Published: March 2006

AbstractKinkazan Island, a sanctuary island that has been conserved for over 100 years, is inhabited by a Sika deer population of high density (60 km−2). A Fagus crenata forest, a climax forest of this region, was composed of only large sized trees (30–60 cm diameter breast height) and lacked young trees. However, many saplings were found inside a deer proof fence, indicating this forest had a potential to produce seedlings. They were tentatively protected by shrubs of Leucothoe grayana var. glabra, an upalatable ericaceous shrub, but did not exceed the shrub height. Heavy browsing by the deer suppressed recruitment of saplings of F. crenata. The forest will be reduced without population control of the deer.