bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photosynthetic characteristics and water use efficiency of three coastal dune plants
Authors: Ishikawa Shin‐ichi , Oikawa Takehisa , Furukawa Akio 
Published: March 2006

AbstractTo clarify the ecophysiological characteristics of plants growing on a coastal dune, net photosynthetic rate (Pn) and leaf conductance (g1) of three perennial species in Japanese coastal regions, Ischaemum anthephoroides (C4), Carex kobomugi (C3) and Calystegia soldanella (C3), were compared under controlled environmental conditions and field conditions at the kado‐ori coast at Ohno Village, Ibaraki. I. anthephoroides achieved photosynthetic CO2 saturation at ca. 100 μll−1 intercellular CO2 concentration (C1), and its Pn was not light‐saturated at a high photosynthetically active photon flux density (PPFD) of 1000 μmol m−2s−1. This C4 species showed a high optimal leaf temperature for Pn (35°C) and a low g1 (0.1 mol H2O m−2s−1), permitting maintenance of the highest water use efficiency (WUE, the ratio of Pn to transpiration rate (Tr)) in the field among the three species. At light saturation, C. soldanella had the lowest Pn and g1 and a similar carboxylation efficiency related to C1 (Pn/C1 ratio) as Carex kobomugi. Calystegia soldanella also had a high optimal temperature for Pn (30°C), and achieved higher WUE than Carex kobomugi, as a result of efficient stomatal regulation. In contrast, at the optimum temperature C. kobomugi had a high Pn comparable to I. anthephoroides due to a high g1 of 0.3 mol H2O m−2s−1, but with high temperature treatments Pn and g1 were significantly decreased. C. kobomugi always had the lowest WUE among the three species in the field. It is therefore clear that I. anthephoroides is a heat‐resistant species, Calystegia soldanella is a heat‐enduring species and Carex kobomugi is a heat‐evading species due to its eraly phenology.
Seasonal change in the redox property of peat and its relation to vegetation in a system of floating mat and pond
Authors: Haraguchi Akira 
Published: March 2006

AbstractA relationship was sought between species distribution and seasonal change in the redox property of peat in a floating mat in Mizorogaike Pond, central Japan. The mat surface experienced an annual submergence‐emergence cycle due to its sinking‐rising movement. Redox potential (Eh) of the surface peat showed little difference between communities in the mat in the submergence season (January–June) and early emergence season (July–August). However variation in Eh among communities was clear in the late emergence season (September–December). Among seven communities in the floating mat, the Menyanthes trifoliata‐Rhynchospora fauriei, M. trifoliata‐Eriocaulon sikokianum‐E. bondoense f. pilosum, Sphagnum cuspidatum and M. trifoliata‐Carex thunbergii communities had high Eh (400–600 mV) in the late emergence season, while the Menyanthes trifoliata and Phragmites australis‐M. trifoliata communities had lower Eh (200–400 mV). The M. trifoliata‐Isachné globosa community was intermediate (300–500 mV). The earlier the emergence of the peat surface began, the higher the Eh became in the late emergence season.
Roles of leaf water potential and soil‐to‐leaf hydraulic conductance in water use by understorey woody plants
Authors: Ishida Atsushi , Yamamura Yasuo , Hori Yoshimichi 
Published: March 2006

AbstractDiurnal changes of leaf water potential and stomatal conductance were measured for 12 deciduous shrubs and tree saplings in the understorey of a temperate forest. Sunflecks raised the leaf temperature by 4°C, and vapor pressure deficit to 2 kPa. Although the duration of the sunflecks was only 17% of daytime, the photon flux density (PFD) of sunflecks was 52% of total PFD on a sunny summer day. Leaf osmotic potential at full turgor decreased in summer, except in some species that have low osmotic potential in the spring. Plants that endured low leaf water potential had rigid cell walls and low osmotic potential at full turgor. These plants did not have lower relative water content and turgor potential than plants with higher leaf water potential. There were three different responses to an increase in transpiration rate: (i) plants had low leaf water potential and slightly increased soil‐to‐leaf hydraulic conductance; (ii) plants decreased leaf water potential and increased the hydraulic conductance; and (iii) plants had high leaf water potential and largely increased the hydraulic conductance.
Three‐dimensional dispersion of drosophilid flies in a cool temperate forest of northern Japan
Authors: Toda Masanori J. 
Published: March 2006

AbstractThree‐dimensional dispersion of drosophilid flies was studied within a secondary broad‐leaved forest in relation to forest structure. The survey area included the forest margin and old canopy gaps and varied in the foliage height profile from place to place. Using multivariate analyses on the data of drosophilid dispersion, five microhabitats which were different from one another for drosophilids were recognized: (i) canopy layer; (ii) middle layer; (iii) floor layer of forest interior; (iv) upper layer of forest margin; and (v) herbaceous layer of forest margin and gap. The height of living space of canopy species was remarkably lowered at the forest margin. The forest edge was richer in both numbers of individuals and species than the forest interior from the overlap of the grassland and the forest canopy subcommunities and the addition of invaders from other habitats. However, no ‘edge’ species, which were mostly restricted to or spend most of their time in ecotones, were found. It is hypothesized that the above‐ground forest structure consists fundamentally of three zones: (i) the canopy; (ii) the floor; and (iii) the edge. A significant positive correlation was found between the foliage height diversity and the degree of vertical habitat segregation among drosophilid species. The patchiness of vegetation structure influential to the three‐dimensional dispersion in a forest drosophilid community was estimated to be on the scale of 110–450 m2. This scale of subjective habitat patchiness or ‘ecological neighbourhood’ corresponds well with the most prevalent size of canopy gaps occurring in various forests.
Dynamics and dry matter production of belowground woody organs of Pinus pumila trees growing on the Kiso mountain range in central Japan
Authors: Kajimoto Takuya 
Published: March 2006

AbstractSize, biomass and spatial distribution patterns of belowground woody organs of Pinus pumila trees were investigated. Dry weight estimates of five sample trees were between 14 and 36 kg tree−1. Belowground stems accounted for about 32% of the total tree weight. However, the belowground stems had extensive barkless portions, indicating that the decomposition of dead belowground stems was an important source of organic matter in the soil. The, basal diameters of adventitious roots tended to become smaller as their orginating positions neared the ground surface. It was suggested that P. pumila trees regenerate by successively producing adventitious roots from their buried stems and moving down the slope.
Carbon isotope ratio and photosynthetic activity of phytoplankton in the eutrophic Mikawa Bay, Japan
Authors: Takahashi Kazushi , Wada Eitaro , Sakamoto Mitsuru 
Published: March 2006

AbstractPrimary production by phytoplankton in the eutrophic Mikawa Bay, Japan, was studied by simultaneous measurements of natural carbon isotope ratio (δ13C) and short‐term carbon uptake rates (13C tracer study) of size‐fractionated nannoplankton (<10 μm) and net plankton (>10 μm) samples. Short‐term photosynthetic rates, which represent the physiological state of algae, were variable regardless of standing stock sizes. The δ13C values of particulate organic carbon (POC) in June and July displayed horizontal variations for both the net plankton fraction (−19.8 to −12.7‰) and the nannoplankton fraction (−22.0 to −12.8‰). For both fractions, low concentrations of POC had more negative δ13C values (−22 to −18‰). High δ13C values for the net plankton were found when POC concentrations were much higher, due to red tide. This suggests that the increase in algal standing crop for the net plankton fraction resulted from accelerated photosynthetic activity. However the nannoplankton fractions with higher POC values have relatively low δ13C values.
Detection of xylem cavitation in field‐grown pine trees using the acoustic emission technique
Authors: Ikeda Takefumi , Ohtsu Masayasu 
Published: March 2006

AbstractThe relationship between the ultrasonic acoustic emission (AE) and the needle water potential in field‐grown Japanese black pine,Pinus thunbergii, and excised‐pine shoots was investigated in summer. The AE technique was employed as a reliable indicator of cavitation events in the water columns of xylem tracheids even under field conditions. In excised shoots. AE events detected when the needle water potential fell below about‐0.9 MPa. In the case of field‐grown pine trees, however, relatively few AE event were detected when needle water potential was lower than‐0.9 MPa. This suggests that the occurrence of cavitation events in Japanese black pine growing under field conditions is comparatively rare, even in summer.
Effect of carbon dioxide concentration on microbial respiration in soil
Authors: Koizumi Hiroshi , Nakadai Toshie , Usami Youzou , Satoh Mitsumasa , Shiyomi Masae , Oikawa Takehisa 
Published: March 2006

AbstractIn order to assess the validity of conventional methods for measuring CO2 flux from soil, the relationship between soil microbial respiration and ambient CO2 concentration was studied using an open‐flow infra‐red gas analyser (IRGA) method. Andosol from an upland field in central Japan was used as a soil sample. Soil microbial respiration activity was depressed with the increase of CO2 concentration in ventilated air from 0 to 1000 ppmv. At 1000 ppmv, the respiration rate was less than half of that at 0 ppmv. Thus, it is likely that soil respiration rate is overestimated by the alkali absorption method, because CO2 concentration in the absorption chamber is much lower than the normal level. Metabolic responses to CO2 concentration were different among groups of soil microorganisms. The bacteria actinomycetes group cultivated on agar medium showed a more sensitive response to the CO2 concentration than the filamentous fungi group.
Impact of extreme run‐off events from the River Sakasagawa on the Senjogahara ecosystem, Nikko National Park III. Pattern of alluvial deposition and effects on the growth of Malus Toringo and Betula platyphylla var. japonica
Authors: Hukusima Tukasa , Mizoguchi Keiko 
Published: March 2006

AbstractIn the study area at Senjogahara, there are 13 vegetational groups forming a space‐time continuum in response to alluvial deposition from the River Sakasagawa. The pattern of deposition changes markedly from time to time, and the vegetation is thus a mosaic of recovery phases in different stages of development.There is marked zonation of layers of gravel, silt and organic matter in the soil profile, running sequentially from the mouth of the river back to the moor. Furthermore, there is a decrease in the depth of the water table with distance from the river mouth. The growth increment of Malus Toringo is poor under the canopy of Ulmus Davidiana var. japonica forest, with maximum growth occurring in the areas of active alluvial deposition. The changing patterns of Malus growth have been used to approximate the dates of major changes in the erosion channels and areas of alluvial deposition.There were five main channels in the study area. The oldest was on the west side and active ca. 35–40 yr prior to 1984, the year of sampling. Subsequently, adjacent areas further east became major drainage and erosion channels about 25–30 yr before 1984. However, after 1985 the erosion channels again showed a marked change in pattern, and currently flow into an entirely different sector, being responsible for the continuous dynamic patterns of vegetational change in this area.
Downhill movement of litter and its implication for ecological studies in three types of forest in Japan
Authors: Tsukamoto Jiro 
Published: March 2006

AbstractThe amount of litter moving down the slope was measured in three types of forest, together with an examination of rain as a factor in bringing this about. The three forest types were a natural mixed stand of Pinus densiflora and hardwood trees (plot A), a Cryptomeria japonica plantation (plot S) and a Chamaecyparis obtusa plantation (plot H). The amount of moved litter was quite large in plots A and H, but relatively small in plot S. The rain factor had little influence on litter movement in plot A, but was the main cause of movement in plot S and (especially) plot H. It is suggested that measurement of litter input and output not only by traps above ground level, but also by ones on the ground is essential for determining the cycling of elements in C. obtusa forests. It is also suggested that the decomposition of leaf litter should be studied both on the soil surface and in the soil in C. obtusa forests.
Productivity‐independent initial growth of individual leaves in sunflower (Helianthus annuus L.)
Authors: Oishi Yuji 
Published: March 2006

AbstractGrowth rates of individual leaves attached to sunflower (Helianthus annuus) plants were measured experimentally under different levels of environmental productivity, modified by irradiance and nutrient conditions. The unfolding rate and final area of an individual leaf increased with increasing environmental productivity. The final area of an individual leaf also varied according to differences in leaf order. The declining pattern of relative leaf area growth rate (RLGR) varied with environmental productivity; leaves in a productive environment had a longer period of high sustained initial RLGR than leaves in a less productive environment. However, maximum RLGR was hardly influenced by leaf order or environmental factors such as irradiance and mineral nutrition.
Factors limiting the distribution of Digitaria adscendens and Eleusine indica on coastal sand dunes in Japan
Authors: Park Yong‐Mok 
Published: March 2006

AbstractFate of Digitaria adscendens and Eleusine indica seedlings under field conditions and their responses to salt spray, drought and nutrients were experimentally investigated in order to evaluate the possible mechanisms controlling the different distributions of the two species in coastal sand dune areas. Salt spray produced no apparent positive effect on the growth or survival of both species. Seeds of each species germinated well in the field, although 80% of E. indica seedlings died during a summer drought and surviving seedlings neither grew nor bore fruit. The mortality of D. adscendens seedlings due to the drought was less than 10% and the survivors mostly bore fruit by the end of the growth season. No major difference in the sublethal water saturation deficit was noticed between the two species. However, D. adscendens individuals extended their roots into the deep sandy soil to a much greater extent in water‐stressed conditions than in well watered conditions, whereas E. indica showed no such behavior. Additional watering in a dune environment did not help the growth of E. indica seedlings, but additional nutrients had a markedly stimulatory effect. D. adscendens maintained its growth and fruition with much smaller amounts of nutrients than E. indica. Soil nitrogen content at a site where E. indica and D. adscendens were distributed sympatrically was higher than that at a site where only D. adscendens was present. Based on these findings, it is proposed that E. indica seedlings are unable to become established because of their lower resistance to summer drought and the poor nutrient conditions present in a coastal rear sand dune habitat.
Principal component analyses of bagged wheat infested with Sitotroga cerealella (Lepidoptera: Gelechiidae) and Sitophilus oryzae (Coleoptera: Curculionidae)
Authors: Imura Osamu , Sinha Ranendra N. 
Published: March 2006

AbstractInterrelations among biological and abiological variables over 22 weeks at 28°C and 60% RH were revealed by principal component analysis (PCA) on data collected from simulated bagged wheat (Triticum aestivum L.) which was not infested by insects (control system), was infested by Sitophilus oryzae (L.) (SO system), by Sitotroga cerealella (Olivier) (SC system) or by both species (SC+SO system). The variables measured were temperature, grain moisture, CO2, dust weight, fat acidity value, grain weight, germination, insect numbers and frequency of occurrence of microfloral species. The analysis indicated the interrelations among variables involved in degradation of the wheat. In the control system, the dominant interrelations were those among abiological variables, indicating that deterioration of the wheat was minimal. In the SO system, principal components which represented insect effects, seed quality and temperature‐fungal relationships, were predominant. Similar factor‐loading patterns were extracted both in the SC and SC+SO systems; the principal components suggested that S. cerealella was mainly responsible for heavy deterioration of the wheat. The principal components, which were rotated orthogonally by 45δ, indicated that the process of wheat degradation in both systems proceeded gradually until week 10 or 15 and thereafter the rate of degradation was accelerated and serious grain quality loss occurred.
The ecosystem concept: A search for order
Authors: Golley Frank B. 
Published: March 2006

AbstractThe development of the ecosystem concept illustrates the search for order in science and shows how individuals and the social‐cultural environment of the science influence concept evolution. Ecosystem was coined in 1935 and replaced a variety of inappropriate terms which all referred to a system of biotic and inorganic interactions in nature. It was popularized after the second World War and became a dominant paradigm in ecology world wide. As such, it dominated the development of productivity studies within the International Biological Program. The ecosystem concept became mature when it was realized that the ecosystem was an object that could be studied directly, using conventional scientific methods. Currently the ecosystem concept exists along side a variety of ecological concepts which represent the guiding research foci of ecological subfields.
Insects and plants in the pollination ecology of the boreal zone
Authors: Kevan P. G. , Tikhmenev E. A. , Usui M. 
Published: March 2006

AbstractPollination systems in the boreal zone range from generalist to specialist, both entomologically and botanically. The relative importance of wind pollination, insect pollination, sexual separation between and within plants, and between flowers, hermaphroditism of flowers, and various breeding systems are related to plant growth form and habitat. The diversity and specializations of anthophilous insects parallel those in other biogeographic zones, but seem less developed. We suggest that this reflects the combined effects of evolutionary youth, severity of climate, restriction of symbiont ranges within those of their hosts, and the naturally frequent perturbations by fire or insect outbreaks in the zone, requiring faunal and floral vagility and constraining specialization in mutualism. Modern perturbations by logging and pesticides seem to be well buffered because of the relative openness of the ecosystem (compared to others), although damage has been documented. Insect pollination is as much a keystone process in the boreal forest as elsewhere, despite the immediate counter‐impression given by the dominance of wind‐pollinated conifers. Nevertheless, there are few studies, botanical or entomologicalin situ. The boreal system offers important opportunities in general and applied research in pollination ecology and synecology generally.
Harvesting rate of the termite, Drepanotermes tamminensis (Hill) within native woodland and shrubland of the Western Australian wheatbelt
Authors: Park H. C. , Majer J. D. , Hobbs R. J. , Bae T. U. 
Published: March 2006

AbstractThe Western Australian termite, Drepanotermes tamminensis (Hill), harvests various plant materials according to biomass availability. The main litter components harvested by this termite in a woodland dominated by Eucalyptus capillosa are bark and leaves of the major tree species, while in shrubland dominated by Allocasuarina campestris, shoots of this species are taken. Harvesting mainly occurs during the autumn (April–May) and spring (September–October) seasons. The commencement and duration of harvesting appears to depend partly on weather conditions, with harvesting taking place at temperatures between 15 and 25°C after periods of rain. This species of termite harvests approximately 15.6 g m−2 year−1 and 3.2 g m2 year−1 (dry weight of plant material) in the woodland and shrubland, respectively.
Spatial variation in composition and richness of fish communities in a southwestern Australian river system
Authors: Hutchison Michael J. 
Published: March 2006

AbstractThirteen species of fish were recorded from the non‐tidal reaches of the Murray River system, southwestern Australia. Of these, nine were indigenous species. Although this system occurs in a zone of moderate to high rainfall, the species richness of this system is comparable to that of much harsher environments, such as the Canadian boreal zone or the Nevada desert. Species richness tends to increase in a downstream direction, and most changes in species composition are due to addition, rather than replacement of species. Stream order was strongly and significantly positively correlated with species richness (P < 0.001), but was in effect functioning as a composite variable. Stepwise multiple regression analysis showed that stream width, pH range, distance from the main stream, distance from the estuary, barriers and stream gradient together explained more than 80% of the variation in species richness. The variables, barriers, distance from the main stream and distance from the estuary, support island biogeography type explanations for variations in species richness, while the variable, stream width complies with the river continuum concept. A predictive model for species richness of any given reach of a lower west coastal stream in Australia was tried using variables that can be gathered almost entirely from detailed topographic maps and aerial photographs.
Interception of photosynthetic photon flux density by woody elements in a hinoki (Chamaecyparis obtusa [Sieb. et Zucc.] Endl.) stand
Authors: Hagihara Akio , Yamaji Kazuyoshi 
Published: March 2006

AbstractA hinoki stand was divided into the following two layers: one was a leafed upper layer consisting of leaves and woody elements, such as stems, living branches and dead branches; the other was a leafless layer consisted of woody elements, such as stems and dead branches. Photosynthetic photon flux density (PPFD) penetrating through the stand was measured in relation to the silhouette area of leaves and woody elements. The silhouette area, on a ground area basis, was 11.2 ha ha−1 for leaves (leaf area index), 0.26 ha ha−1 for stems, 0.40 ha ha−1 for living branches and 0.69 ha ha−1 for dead branches, yielding a total wood silhouette area of 1.35 ha ha−1. The apparent extinction coefficient, K, was computed to be 0.420 ha−1 ha for the leafed layer, while the extinction coefficient of woody elements, Kc, was computed to be 1.01 ha−1 ha for the leafless layer. The cumulative wood silhouette area density from the top of the canopy down to a given depth increased with an increase in the corresponding leaf area density within the leafed layer. The extinction coefficient of leaves, KF, was estimated to be 0.367 ha−1 ha. Of the PPFD extinguished within the canopy, the fraction (KF/K) due to leaves alone was evaluated to be 87.4%.