bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth, morphology and leaf characteristics after simulated herbivory in Chinese subtropical evergreen saplings
Authors: Cornelissen J. H. C. 
Published: March 2006

AbstractGrowth, morphology and leaf characteristics were assessed in late spring following simulated autumnal defoliation in second‐year saplings of three Chinese subtropical evergreen tree species. Castanopsis fargesii showed strong compensatory growth in terms of plant biomass after removal of both 50 and 75% of leaf biomass and slight compensatory growth after 90% defoliation. Defoliated C. fargesii saplings had more leaves per unit shoot length than non‐defoliated saplings. New leaves on defoliated plants were smaller and had higher per area nitrogen content than new leaves on non‐defoliated plants. Pinus massoniana and Elaeocarpus japonicus showed strong and no compensatory growth, respectively, after 50% defoliation. The strong compensatory growth in P. massoniana and C. fargesii may partly explain why these species predominate in the early and late successional phases of evergreen broad‐leaved forests
Pressurized gas transport in two Japanese alder species in relation to their natural habitats
Authors: Grosse Wolfgang , Schulte Angela , Fujita Hiroko 
Published: March 2006

AbstractOxygen uptake measurements have shown that pressurized gas transport, resulting from the physical effect of thermo‐osmosis of gases, improves oxygen supply to the roots of the seedlings in two alder species Alnus japonica (Thunb.) Steud. and Alnus hirsuta (Spach) Rupr., which are both native in Japan. When gas transport conditions were established by irradiation of the tree stems the internal aeration was increased to a level nearly equal to the oxygen demand of the root system in leafless seedlings of A. hirsuta, but was higher in A. japonica so that excess oxygen was excreted into the environment. An increase of superoxide dismutase (SOD) activity, which protects plants from toxic oxygen radicals and post‐anoxic injury, has been observed in root tissues of A. japonica when the seedlings were flooded for 3 days. The increase of SOD activity, in concert with high gas transport rates, may enable this tree species to grow in wet sites characterized by low oxygen partial pressure in the soil and by varying water tables. A less effective gas transport, flood‐induced reduction of SOD activity in root tissues, and reduced height growth in waterlogged soil may be responsible for the fact that A. hirsuta is unable to inhabit wettland sites.
Difference of invasion behavior between two climax species, Castanopsis cuspidata var. sieboldii and Mechilus thunbergii, on lava flows on Miyakejima, Japan
Authors: Hiroki Shozo , Ichino Kazuo 
Published: March 2006

AbstractThe invasion behavior of two climax species, Machilus thunbergii Sieb. et Zucc. and Castanopsis cuspidata (Thunb.) Schottky var. sieboldii (Makino) Nakai, was studied on the 1874 and 1962 lava flows on Miyakejima, Japan. On the 1962 lava, zoochorous M. thunbergii appeared almost only under crowns of pioneering Alnus sieboldiana Matsum, while bolochorous C. cuspidata var. sieboldii occurred only along the borders of the lava. The three species, A. sieboldiana, M. thunbergii and C. cuspidata var. sieboldii, corresponded, in order, to the temporal sequence of invasion in the boundary forest and the spatial sequence from margin to center on the 1962 lava. Seed or fruit dispersion is important in primary succession in the case of large disturbances.
Resource allocation to sexual and vegetative reproduction in a forest herb Syneilesis palmata (Compositae)
Authors: Nishitani Satomi , Kimura Makoto 
Published: March 2006

AbstractThe balance between sexual and vegetative reproduction in Syneilesis palmata was examined in relation to environmental conditions and the amount of reproductive resources, which is defined here as the total quantity of dry matter invested in both modes of reproduction. The allocation balance was measured for individual plants of two populations, with different densities in an open habitat, for 2 years, and those of two other populations, under different light intensities in a plantation forest (forest floor and edge), for 3 years. Relative allocation to sexual reproduction decreased with increasing reproductive resources in all populations except for the forest edge, which showed a constant allocation balance. The high density population showed lower relative allocation to sexual reproduction than the low density population, irrespective of the amount of reproductive resources. However the between‐year comparison of the high density population suggested that under extremely high density, plants with a small amount of reproductive resources enhanced sexual reproduction, while plants with a large amount of reproductive resources reproduced vegetatively. On the forest floor, plants with small amounts of reproductive resources had higher relative allocation to sexual reproduction than the forest edge population, while plants with large amounts of reproductive resources had a somewhat lower one. The adaptive significance of such allocation patterns are discussed, based on qualitative data on the characteristics of both types of offspring.
Probable effects of CO2‐induced climatic changes on net primary productivity of terrestrial vegetation in East Asia
Authors: Ohta Shunji , Uchijima Zenbei , Oshima Yasuyuki 
Published: March 2006

AbstractChanges in the net primary productivity (NPP) of natural vegetation of monsoon East Asia were simulated under three, doubled CO2‐climate scenarios (GISS, GFDL and UKMO). These three scenarios and baseline climate data were converted to grids of 1o×1o meshes. The gridded climatic data were used together with the Chikugo model to assess NPP under baseline and CO2‐doubling climates. The potential total net production (TNP0) of East Asia was climatically evaluated to be 154×108 t dry matter year−1. The climatic changes induced by a doubled CO2 concentration are predicted to increase the TNP0 by approximately 9–15%, depending on the climatic scenario. The estimated increase in TNP0 would be limited by the difference between the rate of shift of climatic zones and the rate of migration of vegetation formations.
Differences in sapling architecture between Fagus crenata and Fagus japonica
Authors: Yamamura Yasuo , Ishida Atsushi , Hori Yoshimichi 
Published: March 2006

AbstractThe ecological significance of architectural patterns for saplings of Fagus crenata and Fagus japonica co‐occurring in a secondary oak forest were evaluated by comparing the size and shape of leaves, trunks and crowns. Fagus japonica saplings were different from F. crenata saplings in some architectural properties: (i) the leaf area and specific leaf area were larger; (ii) the ratio of sapling height to trunk length was lower, indicating greater leaning of the trunk; and (iii) the projection area of the crown was larger and the leaf area index lower indicating less mutual shading of leaves. These architectural features indicated that F. japonica saplings were more shade tolerant than F. crenata and F. crenata saplings were superior to F. japonica for growth in height and could, therefore, utilize sunlight in the upper layer. An erect trunk in F. crenata and a leaning trunk in F. japonica may be important characteristics associated with the regenerations patterns of each species; regeneration from seedlings under canopy gaps in the former and vegetative regeneration by sprouting in the latter.
The ecology of a beech forest on Mt. Sanpoiwadake, Hakusan National Park, Japan II. The correlation of the subassociation within the Lindero membranaceae‐fagetum crenatae association and environmental parameters
Authors: Hukusima Tukasa , Kershaw Kennth Andrew 
Published: March 2006

AbstractDetailed examination of a sample plot covered by the Lindero membranaceae‐Fagetum crenatae association on Mt. Sanpoiwadake, Hakusan National Park, revealed a number of correlations between the distribution of subassociations and environmental factors.The subassociations on the south‐facing slopes receive deep snow cover in winter with rapid melting in the spring. They occur on porous, freely draining soils, typical of the general range of brown forest soils. Conversely, on the north‐eastern slopes there are widespread late‐snow patches which delay leaf development and expansion and which provide an abundant water supply well into early summer. Under these conditions, bleached soil horizons have developed with iron pan formation, resulting in poor soil drainage, strongly correlated with quite different plant communities.
Rhizome development of Phragmites australis in a reed community
Authors: Kudo Gaku , Ito Koji 
Published: March 2006

AbstractVariations in the height, shoot density, biomasses of above‐ and below‐ground parts and rhizome distributions of Phragmites australis were investigated along a line‐transect in a reed community at Yufutsu Mire, Hokkaido. Relationships of performance of the reed plants to soil conditions and species compositions were also examined.Three types of rhizome development were recognized in reed plants; (1) the central part of the reed community, characterized by well developed rhizomes and dense aerial shoots, (2) the intermediate part, characterized by development of rhizomes along both the peat and surface layers and very dense aerial shoots, and (3) the marginal part, characterized by development of rhizomes only along the peat layer and sparse aerial shoots.Observation showed that rhizomes in the surface layer actively produced aerial shoots, whereas rhizomes in the peat layer contributed to the spreading of their distribution range. With the growth of rhizomes, organic debris originating from dead rhizomes and roots accumulated in the mineral soil to promote organic soil formation. In dense parts of the reed stand, species composition was poor because of the shading and litter accumulation by reed plants. The effects of microtopography and water level on the establishment of reed seedlings were also considered.
Population dynamics of Daphnia rosea in a small eutrophic pond
Authors: Shei Ping , Iwakuma Toshio 
Published: March 2006

AbstractThe population dynamics of Daphnia rosea were studied in a small, eutrophic fish‐free pond during November 1986–November 1987. D. rosea showed two density peaks in 1987, a high peak in spring and a slightly lower one in autumn, but they disappeared in mid‐ and late summer when a smaller cladoceran, Ceriodaphnia reticulata, dominated.The rapid decline in density of D. rosea in mid‐May and the low density in June/July were preceded by or coincided with a period of increased male density, the appearance of ephippial females, smaller body length of adult females, decreased brood size, and increased frequency of empty brood chambers, all of which indicate a worsening food situation. The rapid density decline of D. rosea in mid‐May was considered attributable neither to increasing water temperature, nor predation by the dipteran Chaoborus flavicans, but to insufficient food conditions for the maintenance of stable reproduction. Although edible phytoplankton was abundant in June/July, the general food situation was not suitable for D. rosea due to blooms of the large‐celled dinoflagellate, Ceratium hirundinella, which probably inhibited the feeding activity of D. rosea. The C. hirundinella blooms might also be important for the shift of the dominant herbivore from the larger D. rosea to the smaller Ceriodaphnia reticulata in August/September.
Foraging behavior of Ural owls (Strix uralensis) in a patchy environment: The importance of acquired information
Authors: Nishimura Kinya 
Published: March 2006

AbstractHow the allocation of searching investiment by Ural owls (Strix uralensis) in a patchy and fluctuating environment is affected by prior information was experimentally studied. The owls searched among four patches, two with prey and two without prey. During the five days, the positions of two prey patches were randomly assigned daily (random treatment) and for the other five days, they were fixed (fixed treatment). In experiment I, the sequence of treatments was from random to fixed. In experiment II, the sequence of treatments was reversed. The choice of prey present patch was affected by acquired information which owls acquired during one night (short term), a treatment period (medium term), and throughout the experiment run (long term). They predicted the positions of the prey patches, to some extent, in the first choice in one night in the fixed treatment by the experience of previous days. The searching time per visit was also affected by previous information. Owls searched prey patches longer than empty patches. In the random treatment, the giving up time in prey patches was variable, while in the fixed treatment, it was longer and fixed. Although owls could use information on the environment where they had searched to make a decision of foraging behavior, they were not able to choose prey patches accurately. The information which was acquired during the treatment period and throughout the experiment run affected the gain from prey. The changes in gain were not caused by the encounter rate but by the proportion of attack success.
Population dynamics of japanese serow in relation to social organization and habitat conditions. I. Stability of Japanese serow density in stable habitat conditions
Authors: Ochiai Keiji , Nakama Satoru , Hanawa Sin‐Ichi , Amagasa Toshifumi 
Published: March 2006

AbstractThe density of a Japanese serow (Capricornis crispus) population, which has been in stable habitat conditions and free from hunting and predation, was investigated by direct observation of serows at Kusoudomari (336 ha), Wakinosawa village, Aomori Prefecture, Japan, during 1977–89. The vegetation, composed of mature mixed forest of Thujopsis with deciduous trees (43.2%), secondary forest of deciduous trees (23.4%) and a plantation of coniferous trees (30.0%) showed little change during the study period. The serows were counted 17 times each winter for 14 consecutive years. The serow population maintained a stable density with a mean of 12.5 individuals km−2 (SD=1.4) ranging from 8.6 to 14.6 km−2. The ratio of the proportion of kids (<1 year old) to serows more than 1 year old decreased, but density did not decrease during the study period. Though extremely severe winters with heavy snowfall in 1984–86 caused a decline in serow density, the density recovered within a few years. It was considered that the stability of the serow density resulted mainly from the stable food supply and the lack of human disturbance, such as forest cutting in the habitat. Stable population density for a long period is probably related to the social organization of the serow.
Botanical and chemical composition of rumen contents of Sika deer on Mt Goyo, northern Japan
Authors: Takatsuki Seiki , Ikeda Shoshichi 
Published: March 2006

AbstractBotanical and chemical compositions of the rumen contents of 58 Sika deer on Mt Goyo, northern Japan, collected from summer of 1988 to spring of 1989, were analyzed. Sasa nipponica, a dwarf bamboo, was important in summer (35.0%) and winter (61.4%), but it decreased to 5.6% and was replaced by browse leaves in fall, and to 28.0% and was replaced by dead leaves, twigs and bark of woody plants in winter. Crude protein was 20–25% lower in the washed fraction than in the gross fraction. It was highest (16.2%) in summer and lowest (8.6%) in winter. High protein content in summer and fall foods was attributed to forb and browse leaves. Seasonal fluctuation in protein content in the foods of these Sika deer was greater than red deer on Rhum, Scotland and smaller than wapiti in Yellowstone National Park, Wyoming, USA. Climatically, winter severity of Mt Goyo is intermediate between the two localities, which seems to explain the seasonal fluctuation of the protein level. Crude fiber was ca 33% in the ‘washed’ fraction, and did not change seasonally.
Examination of the method for measuring soil respiration in cultivated land: Effect of carbon dioxide concentration on soil respiration
Authors: Nakadai Toshie , Koizumi Hiroshi , Usami Youzou , Satoh Mitsumasa , Oikawa Takehisa 
Published: March 2006

AbstractAn acceleration of soil respiration with decreasing CO2 concentration was suggested in the field measurements. The result supporrs that obtained in laboratory experiments in our previous study. The CO2 concentrations in a chamber of the alkali absorption method (the AA‐method) were about 150–250 parts/106 lower than that in the atmosphere (about 350 parts/106), while those observed in the open‐flow IRGA method (the OF‐method) were nearly equal to the soil surface CO2 levels. The AA‐method at such low CO2 levels in the chamber appears to overestimate the soil respiration. Our results showed that the rates obtained by the AA‐method were about twice as large as those by the OF‐method in field and laboratory measurements. This finding has important consequences with respect to the validity of the existing data obtained by the AA‐method and the estimation of changes in the terrestrial carbon flow with elevated CO2
Photosynthesis of bract and its contribution to seed maturity in Carpinus laxiflora
Authors: Hori Yoshimichi , Tsuge Hiromi 
Published: March 2006

AbstractLight saturated net photosynthesis was measured in bracts and leaves of Carpinus laxiflora, the major species in secondary forests in cool and intermediate temperate zones in Japan. The maximum net photosynthesis of leaves and bracts was essentially constant from May to early August and decreased gradually thereafter. For bracts, it was 3.2 μmol m−2s−1, approximately half that for the leaves. The photosynthesis of bracts would thus appear to contribute significantly to seed maturity. The estimated production of bract based on the photosynthesis would make seeds (3 mg dry weight) mature for 37 days, assuming all photosynthate of the bracts to have been distributed in the seeds only. This was quite consistent with the growth curve for the seeds. A mast year phenomenon is discussed in relation to bract photosynthesis and leaf number.
Field measurements of nitrogen‐fixing activity of intact saplings of Alnus maximowiczii in the subalpine zone of Mt Fuji
Authors: Tsutsumi Hiroshi , Nakatsubo Takayuki , Ino Yoshio 
Published: March 2006

AbstractNitrogen‐fixing (acetylene‐reducing) activity of intact saplings of Alnus maximowiczii was measured under natural conditions in the subalpine zone of Mt Fuji. The nitrogen‐fixing activity was detected from the middle of June when expansion of leaves had just begun to the end of October when the shedding of leaves was almost completed. Diurnal changes in the activity were almost parallel with those of ground temperature. The measured nitrogen‐fixing activity was related to ground temperature and total leaf area. Using this relation, annual nitrogen fixation was estimated from the data of ground temperature and leaf area measured in the field. The amount of annual nitrogen fixation was almost the same as that of nitrogen used for annual growth. It was concluded that nitrogen fixation by nodules made a considerable contribution to the nitrogen economy in the saplings of A. maximowiczii.
Fecundity and oviposition in three skimmers, Orthetrum japonicum, O. albistylum and O. triangulare (Odonata: Libellulidae)
Authors: Higashi Takayoshi , Watanabe Mamoru 
Published: March 2006

AbstractFemales of three skimmers, Orthetrum japonicum, O. albistylum and O. triangulare, were captured in forests and paddy fields. They were dissected and examined for the number of submature and mature eggs. Orthetrum japonicum and O. albistylum continuously developed eggs throughout their reproductive period. The volume of mature eggs in O. albistylum was the smallest among the three species. The number of mature eggs in ovaries decreased from morning to afternoon, suggesting that all of them oviposited around noon. The number of mature eggs laid by O. japonicum, O. albistylum and O. triangulare was estimated at about 400, 800 and >2000 a day, respectively.
Nitrogen cycling in an Antarctic ecosystem 2. Estimation of the amount of nitrogen fixation in a moss community on East Ongul Island
Authors: Nakatsubo Takayuki , Ino Yoshio 
Published: March 2006

AbstractNitrogen fixation by cyanobacteria in a moss community on East Ongul Island (69°00'S 39°35′E), Antarctica was investigated using the acetylene reduction method.The mean acetylene reduction rate at 10°C and 200 μE·m−2·s−1 photosynthetically active radiation was 7.12 nmol C2H4 per square centimeter of moss community per hour. The effects of temperature, radiation, desiccation and rehydration on the acetylene reduction rates were examined.A simple predictive model was constructed in order to estimate the amount of nitrogen fixed in the field. Using this model, the daily amount of nitrogen fixation was calculated from microclimatic data (temperature and radiation) measured in the experimental field at Syowa Station on East Ongul Island between 1983 and 1984. The cumulative amount of nitrogen fixation in the growing season during this period was estimated to be 329 mg N per square meter of moss community.It is suggested that nitrogen fixation by cyanobacteria in the moss community is important as a nitrogen source for the community growth on East Ongul Island.
Regeneration process of coniferous forests in northern Hokkaido I. Abies sachalinensis forest and Picea glehnii forest
Authors: Suzuki Eizi , Ota Kasio , Igarashi Tsuneo , Fujiwara Koichiro 
Published: March 2006

AbstractRegeneration of natural forests was studied in the Nakagawa Experiment Forest of Hokkaido University using age distribution surveys made by the clear felling method. In Plot 1 (30 m × 65 m), Abies sachalinensis dominated the canopy layer but there were also a few Betula ermanii trees. Sasa senanensis densely covered the forest floor. Most of the canopy trees were from 122 to 195 years old. Seedlings younger than 50 years old of A. sachalinensis were found on fallen logs and root bases. There were, however, few trees from 50 to 120 years old. The present canopy trees seemed to have regenerated after competitive pressure from old canopy and Sasa disappeared 180 years ago. Plot 2 (50 m × 100 m) on serpentinite soil was dominated by Picea glehnii. Sasa kulirensis covered the floor but not as densely as S. senanensis in Plot 1. The ages of P. glehnii ranged from 1 to 586 years old, and the age distribution of A. sachalinensis was L‐shaped. A small gap in the canopy formed about 290 years ago, and it gradually extended. Conifers regenerated continuously in the extending gap but B. ermanii did not. One hundred thirty years ago, part of Plot 2 was again destroyed and A. sachalinensis and B. ermanii regenerated. Thus, two types of regeneration were found. One regenerated both conifers and Betula after a sudden disturbance of canopy layer or death of Sasa, and the other, under an extending gap, regenerated only conifers.
The impact on the Senjogahara ecosystem of extreme run‐off events from the river Sakasagawa, Nikko National Park
Authors: Hukusima Tukasa , Kershaw Kenneth Andrew , Looney John Henry 
Published: March 2006

AbstractVegetational data from Senjogahara moor, Nikko National Park, Japan have been analysed using two contrasting but parallel multivariate approaches as a basis for future studies. The plant communities objectively defined using a divisive polythetic classificatory approach (TWINSPAN) have been successfully overlayed on an ordination of the same data using detrended correspondence analysis (DCA). The results reveal a vegetational mosaic reflecting differential levels of flood damage to the vegetation and its subsequent rates of recovery, in a space‐time continuum. The results from the TWINSPAN classification show that 13 plant communities are present in the sample area and these correlate closely with complete absence, slight, or extremely heavy disturbance. The form of the disturbance as either channel erosion or alluvial depositional features is shown to also correspond quite closely with the vegetational types and is reflected in the ordination axes derived from DCA.