bluuebunny/crossref_metadata_2025_split huggingface dataset:
Population dynamics, productivity and biomass allocation of Zizania latifolia in an aquatic‐terrestrial ecotone
Authors: Tsuchiya Takayoshi , Shinozuka Atsushi , Ikusima Isao 
Published: March 2006

AbstractThe population and production ecology of a Zizania latifolia stand at a sheltered shore of the Hitachi‐Tone River were investigated. Shoot emergence was observed twice a year; the fist was a synchronized shoot emergence in April and the second was from August to October. Aboveground biomass was mostly occupied by leaves and peaked at 1500 g dry weight m−2 in August. The belowground biomass also reached its peak, 750 g dry weight m−2, in August. The secondary shoots were small in spite of their high density. Leaves were produced continuously throughout the season. The leaf life span was as short as 55.6 days for cohorts that emerged from May through to September. Total annual net production of Z. latifolia could be more than 3400 g dry weight m−2. Shoot clusters of several centimeters were observed in April. The following self‐thinning caused a regular distribution of the remaining shoots in August. Most shoots produced in August to October were found near a shoot persisting since April. They showed more concentrated distribution than shoots in April. A large biomass allocation to leaves and the ability to produce many clump shoots during the late growing period may facilitate dominance of Z. latifolia in relatively sheltered sites.
Recovery of a Sasa tsuboiana population after mass flowering and death
Authors: Makita Akifumi , Konno Yasuo , Fujita Noboru , Takada Ken′ichi , Hamabata Etsuji 
Published: March 2006

AbstractThe recovery process of a Sasa tsuboiana population after a mass flowering and death in 1977 was investigated by 15 years of observation in the Hira Mountains, Kinki district, western Japan. Seed production was high (6600–13 800 seeds m−2 in Sasa plots and 3900 seeds m−2 in a forest plot) but emergent seedling density was low (14–21 seedlings m−2), probably because of seed predation by Microtus montebelli occurring between seed shedding and the next spring. The seedling density had decreased further by the next year and the S. tsuboiana population recovered from only a limited number of seedlings. In spite of such a low initial density, the S. tsuboiana population was able to regenerate successfully and attained the previous full stand height in 7–16 years. Miscantbus sinensis invaded and delayed the recovery of S. tsuboiana in one plot, but S. tsuboiana became dominant as it caught up with the height of M. sinensis. Seedling growth patterns, such as frequent tillering, the onset of rhizome extension in the early stage of seedling growth and frequent culm production from rhizomes, played important roles in the successful regeneration of S. tsuboiana.
Reproductive behavior of females and its relation to the mating success of two male forms in Mnais pruinosa (Zygoptera: Calopterygidae)
Authors: Nomakuchi Shintaro 
Published: March 2006

AbstractThe behavior of females of the damselfly Mnais pruinosa was observed in the breeding season. Males consisted of both territorial (esakii) and non‐territorial (strigata) types in the study area. Females sometimes arrived at a stream for mating and oviposition. The staying time of females in the stream was 1–3 hours, while that of males was 5–8 hours. The proportion of the males that copulated with the females did not differ between the two male forms present in the stream. In the Calopterygidae, of which the females usually perform multiple copulation, oviposition without subsequent recopulation is considered to be advantageous for a mated male in order to avoid the risk of sperm displacement. From such a viewpoint, the time spent for oviposition was measured for females that arrived at the stream after copulation with different male forms. The ratio was 69.1: 11.5–30.9 between esakii and strigata males. Assuming that the oviposition time is proportional to the number of fertilized eggs laid, this ratio would represent the relative reproductive success of the two male forms. In fact, the relative abundance of the two male forms was also biased in favor of esakii males (61.7:38.3) in this population. The mechanism of coexistence of the two male forms is discussed in relation to their reproductive success.
Consequences of host plant chemical and physical variability to an associated herbivore
Authors: Waring Gwendolyn L. 
Published: March 2006

AbstractThe effects of watering and fertilizer treatments on the vigor and biochemistry of the willow, Salix lasiolepis, and subsequent colonization and survivorship of its gallforming herbivore, Euura lasiolepsis, were investigated in two field experiments. Some plants received low (LW), intermediate (MW) or high (HW) levels of water as treatments, while others received no (OF), low (LF) or high (HF) fertilizer levels. In the watering experiment, plant protein concentrations decreased, while growth rate and number of galls per plant increased with increased water treatments. Plant growth proved to be the best correlate of sawfly attack. Sawfly survivorship increased slightly with greater watering, and phenol concentrations showed no pattern among treatments. In the fertilization experiment, leaf protein increased with fertilization, although shoot length, number of galls and survivorship of E. lasiolepis survivorship were greatest in intermediate treatment plants. In both experiments, plant growth, rather than protein or phenol levels, was the best predictor of sawfly attack and survivorship.In a natural experiment with galls on wild plants, galled tissue had significantly greater protein concentrations and lower phenol concentrations than did ungalled tissue. We suggest that gallformers modify host plant biochemistry within willow galls, which may explain why the chemical parameters of ambient plant quality we tested were less predictive than plant growth.
Establishment and growth of mangrove seedling in mangrove forests of southern Thailand
Authors: Tamai Shigenobu , Iampa Patcharee 
Published: March 2006

AbstractThe demography and growth of mangrove seedlings in southern Thailand were studied for an 18‐month period. Plots for measurement of seedlings were established using gradients of light and surface soil texture.The number of established propagules peaked from April to August, the peak for Rhizophora being earlier than that for Bruguiera. Under the mangrove forest canopy, the survivorship of seedlings established during May to December 1982 was 33% in June 1983.Light conditions and soil texture did not strongly affect initial seedling establishment, and the relationship between species seed size and water depth at a particular site influenced that were able to become established there. The elongation growth was large during the rainy season and in open sites. The growth of R. apiculata Blume, B. parviflora Wight & Arn. and B. cylindrica Blume in open sites was more than ten times that of seedlings established in the shade.It has noted that light conditions affected the growth of young trees (>1 year old) to a greater degree than that of current‐year seedlings.
Fluctuation of photosynthetic photon flux density within a Miscanthus sinensis canopy
Authors: Tang Yan‐Hong , Washitani Izumi , Tsuchiya Takayoshi , Iwaki Hideo 
Published: March 2006

AbstractDetailed measurements of diurnal variations in photosynthetic photon flux density (PPFD) were made at seven locations within the canopy of a Miscanthus sinensis grassland to evaluate the light conditions of microsites for heliophilic tree seedlings. Multiple regression analysis revealed that the short‐term light fluctuation on a clear day was highly dependent on the wind speed and solar elevation angle, whereas on a cloudy day it was mainly determined by the PPFD incident from above the canopy.The relative PPFD at 40 cm aboveground varied from 0.065 to 0.252, depending on sky conditions and the sensor's position in relation to clumped patches of M. sinensis. On a clear day, the proportion of PPFD readings above 100 μmol·m−2·s−1 contributed by sunflecks ranged between 25.4% and 82.0%. Computer simulation showed that the contribution of sunflecks to the daily carbon gain of Quercus serrata seedlings may range from 11% to 65%.The mean relative PPFD measured under diffuse light conditions was linearly related to the daily total PPFD and the daily carbon gain by single leaves of Q. serrata seedlings. This suggests that the relative PPFD under diffuse light conditions provides an appropriate measure of site‐specific light availability within a grass canopy.
The structure of a local population and dispersal pattern in the Styan's grasshopper warbler, Locustella pleskei
Authors: Nagata Hisashi 
Published: March 2006

AbstractThe breeding sites of Styan's grasshopper warblers are restricted to small islands and distributed discretely. The study on the marked population was conducted on two islets, Okitsu‐jima and Ohtsukue‐jima, located near Fukuoka, Japan, from 1981 to 1989. About 20 and 70 birds bred on the two islets, respectively, and the mean density of breeding pairs was 25.5 ha−1. The dispersal pattern and population, structure were examined. Adult birds returned to the same breeding site. Males always reoccupied the same territory as in previous years but females not. Males were more philopatric and only female yearlings dispersed over long distances and moved between the breeding sites in Hakata Bay. The returning rate was 0.57 for adults, and 0.21 for juveniles. The age distribution of birds at Ohtsukue‐jima was almost stable, while that at Okitsu‐jima was unstable because it was a marginal habitat for the birds. Estimating from the dispersal pattern and age structure of this warbler the population near Fukuoka consists of only four islets and is almost stable.
Vegetation pattern and microtopography on a landslide scar of Mt Kiyosumi, central Japan
Authors: Sakai Akiko , Ohsawa Masahiko 
Published: March 2006

AbstractVegetation pattern and microtopography were examined on a mountain slope with a rotational type landslide scar on Mt Kiyosumi, central Japan. Similarities of distribution patterns among 55 woody species were calculated using Cole's species association coefficient, and based on them, seven vegetation units were classified using cluster analysis and principal coordinates analysis. The seven vegetation units coincide with seven microtopographical facets at 101 to 102 m2 order. Furthermore, these vegetation units were grouped into three higher categories by reciprocal averaging and principal coordinates analysis. They were ridge slopes, surrounding slopes and landslide slopes. The three categories were arranged in the above‐mentioned order based on similarity in floristic composition. In the ridge slopes, late‐successional trees and deciduous trees had high relative basal areas. In the surrounding slopes, Euptelea polyandra and other deciduous trees had high relative basal areas. In the landslide slopes, E. polyandra and deciduous shrubs had high relative basal areas. The density and the age distributions of E. polyandra, a typical pioneer tree which invades disturbed sites, suggested that the severity of soil surface disturbances increase in this order. The disturbance regime explains the vegetation pattern on the study site, where the rotational type landslide had occurred.
Comparative ecophysiology ofLarix kaempferi(Lamb.) Carr. andAbies veitchiiLindl. III. Analysis of factors determining the differences in root depth
Authors: Yura Hiroshi 
Published: March 2006

AbstractA new method for analyzing growth is proposed to elucidate factors responsible for the differences in root depth ofLarix kaempferiandAbies veitchiiseedlings. Root depth (D) divides into three factors;urn:x-wiley:09123814:ere0073:equation:ere0073-math-0001where DW and L are dry weight of the root and total length of root elements, respectively. L/DW, specific root length, and D/L ratio represents the length of the root per unit root dry weight and the ratio of the depth to the total length of the root elements, respectively. Seedlings of the two species were grown from seeds and values of these three factors; root dry weight, specific root length and D/L ratio were periodically compared between the two species during growth. Irrespective of watering conditions, the factor that was almost entirely responsible for the differences in root depth between these two species was differences in specific root length, while there were virtually no differences in root dry weight or D/L ratio, indicating that allocation of dry mass to the root is equivalent and geometrical structure of the root system is similar. It is therefore concluded that the deeper roots which enableL. kaempferiseedlings to establish themselves during drought conditions on bare ground, unlikeA. veitchiiseedlings whose establishment is confined to the forest floor, are attained by their ability to extend their roots longer for a given amount of dry mass.
Analytical studies on the responses of sunflower (Helianthus annuus) to various defoliation treatments
Authors: Mariko Shigeru , Hogetsu Kinji 
Published: March 2006

AbstractThe effects of defoliation treatments on plant growth in sunflower (Helianthus annuus) were studied in the field. Four defoliation treatments, 0 (control), 37.4, 56.1 and 93.4% of the total leaf dry weight, were applied to plants that had small third leaves. Decreased leaf weight/whole plant weight (F/W) ratios in defoliated plants rapidly recovered to almost the same ratio as that observed in the control within 12 to 16 days after defoliation according to the degree of defoliation. The mechanism involved in the recovery of the F/W ratio in defoliated plants mainly consisted of three parameters: enhancement of (1) carbon distribution ratios in the leaves, (2) photosynthetic activity in the remaining leaves, and (3) retranslocation of carbon from the stem and/or roots to leaves.Inhibitive effects of defoliation on relative growth rate and net assimilation rate were seen at an early stage, but subsequently both rates became larger in defoliated plants than in controls. Defoliated plants tended to show rapid development and expansion of new leaves, and to show increased specific leaf area and protein synthesis in individual leaves. The sugar content of leaves in defoliated plants was higher than that in controls, while the content in both stem and roots was lower. These responses seem to be advantageous for development of the photosynthetic system. Heights of defoliated plants were clearly depressed according to the degree of defoliation, and this was attributed largely to differences in the elongation rates of the internodes resulting from defoliation.
Studies on ecology and behavior of Japanese black swallowtail butterflies. 6. Nectar feeding of Papilio helenus nicconicolens Butler and P. protenor demetrius Cramer as main pollinators of glory bower, Clerodendron trichotomum, Thunb
Authors: Suzuki Nobuhiko , Yamashita Keiko , Niizuma Akio , Kiritani Keizi 
Published: March 2006

AbstractThe butterflies Papilio helenus and P. protenor were shown to feed mainly on the nectar of the glory bower, Clerodendron trichotomum, which was the most abundant nectar plant in summer in the study area. Both the species were found to have a proboscis longer than 24 mm corresponding to the length of the corolla tube of C. trichotomum. Visits to the flowers by these butterflies were observed more frequently than visits by sphingid moths which had previously been believed to be the major pollinators of C. trichotomum. The male butterflies visited trees of C. trichotomum frequently, while visits by the females were less frequent. However, once females had visited the tree of C. trichotomum, they remained there longer than the males. Since the flower of C. trichotomum has long protruding sexual organs, its pollen grains were found to adhere efficiently to the bodies of butterflies, mainly the thorax, during nectar feeding. Most of the butterflies became loaded with C. trichotomum pollen, and the mean number of pollen grains per butterfly was 1,776 for P. helenus and 2,817 for P. protenor. The flowers opened at any time of day but more frequently in the morning. The nectar was secreted throughout the day. In the maturation of the protandrous flower of C. trichotomum, the duration of the pistillate phase was about twice as long as the staminate phase. The long flowering period and the short duration of the staminate phase resulted in asynchrony of the flowering stages even within a single cyme on a tree. Such asynchrony and the abundance of attractive flowers on a tree facilitates efficient pollination by the butterflies.
The species composition and diversity of tree‐dwelling beetles in deciduous oak and evergreen forests in central Japan; Relationship between the diversity index and sample size
Authors: Isono Masahiro , Takeda Susumu , Sakurai Hironori 
Published: March 2006

AbstractDuring the period fromlate May through December 1981, tree‐dwelling beetles were regularly surveyed at three deciduous oak and two evergreen forests in the vicinity of Gifu City. Chrysomelidae and Curculionidae were abundant in these forests. The species diversity and the seasonal succession of species were most apparent in May and June. The three deciduous oak forests, with many species and high equitability, showed more diverse community structure, but fewer individuals, when compared with the two evergreen forests. Furthermore, the species compositions of the deciduous oak forests were seasonally and spatially more heterogeneous than those of the evergreen forests. A few dominant species, however, had a strong influence on the community structure. The relationship between the diversity index and sample size was examined. The diversity index changed with the sample size, and the range of the variation diminished as the sample size increased. However, equilibrium was not reached even in the largest sample size used in this study (20 samples). There was a significantly high correlation (P<0.001) in diversity index between the smaller sample sizes (5, 10, 15) and the largest. It was, therefore, shown that community structures can be compared on the basis of the diversity indices from samples of constant size, even when the samples are small.
Does the seston of Lake Biwa release dissolved inorganic nitrogen and phosphorus during aerobic decomposition?: Its implication for eutrophication
Authors: Tezuka Yasuhiko 
Published: March 2006

AbstractSeston was collected from depths of 5 and 60 m in the north basin and a depth of 0 m in the south basin of Lake Biwa in the summer of 1985 and decomposed in the laboratory under aerobic conditions for three months. There was no net release of dissolved inorganic phosphorus from any seston, in contrast with the liberation of dissolved inorganic nitrogen. From this result and other available data, it is suggested that almost all phosphorus entering Lake Biwa and remaining within it is finally transformed into particulate phosphorous, transported to the bottom sediments, and fixed there without being recycled. Thus, this mechanism seems to play an important role in the prevention of rapid eutrophication of Lake Biwa, in spite of high external phosphorus loading.
A new life table of leaves of Phaseolus vulgris L. in relation to their position within the canopy and plant density
Authors: Miyaji Ken‐ichi 
Published: March 2006

AbstractIn order to demonstrate in detail the relationship between the longevity and productivity of leaves within a canopy, a new life table approach, the ‘bioeconomic life table’, was applied to the leaves of kidney bean plants (Phaseolus vulgaris L.) in relation to planting density and their position within the canopy.The net photosynthetic rate for upper leaves under full daylight tended to decline gradually due to leaf senescence from about 20 days after leaf emergence, and for the lower leaves the decrease was very rapid due to both shading and senescence about 10 days after emergence.Analysis of the survivorship curves and daily surplus production of leaves suggested that the lower and middle leaves, especially the latter, survived without surplus production of dry matter after they had reached mean longevity, and while the upper leaves at high density had a much shorter mean longevity, they had very large values of daily surplus production throughout the survival period.For the total foliage, the summed value of accumulated surplus production during the survival period was about five times as large as the summed value of the dry weight of the dead leaves, regardless of planting density.The daily rate of canopy leaf respiration was almost proportional to that of canopy gross photosynthesis for the various leaf area indices of the canopy, so that there was no optimum leaf area index that maximized canopy daily surplus production.
Spatial coexistence of phytoplankton species in ecological timescale
Authors: Miyazaki Tatsuo , Tainaka Kei‐ichi , Togashi Tatsuya , Suzuki Takanori , Yoshimura Jin 
Published: March 2006

AbstractThe species diversity of phytoplankton is usually very high in wild aquatic systems, as seen in the paradox of plankton. Coexistence of many competitive phytoplankton species is extremely common in nature. However, experiments and mathematical theories show that interspecific competition often leads to the extinction of most inferior species. Here, we present a lattice version of a multi‐species Lotka–Volterra competition model to demonstrate the importance of local interaction. Its mathematical equilibrium is the exclusion of all but one superior species. However, temporal coexistence of many competitive species is possible in an ecological time scale if interactions are local instead of global. This implies that the time scale is elongated many orders when interactions are local. Extremely high species diversity of phytoplankton in aquatic systems may be maintained by spatial coexistence in an ecological time scale.
Back to the Future? Making Sense of the 2004 Canadian Election
outside Quebec
Authors: Gidengil Elisabeth , Blais André , Everitt Joanna , Fournier Patrick , Nevitte Neil 
Published: March 2006

Abstract. This paper uses data from the 2004 Canadian
Election Study to analyze the factors that motivated a vote for each party
and to identify the ones that mattered most to the outcome of the 2004
federal election outside Quebec. Particular attention is given to the
impact of the sponsorship scandal, the sources of support for the new
Conservative party and the factors that explain the NDP's improved
performance. The findings are used to address some basic questions about
the 2004 election and its larger implications.Résumé. L'article utilise les
données de L'Étude électorale canadienne de 2004
pour identifier les principaux facteurs qui ont motivé l'appui
aux différents partis et pour jauger leur impact sur le
résultat de l'élection à l'extérieur
du Québec. Les auteurs accordent une attention particulière
aux effets du scandale des commandites, aux sources de l'appui au
nouveau Parti conservateur et aux raisons sous-jacentes des gains du NPD.
Les résultats permettent de répondre à un certain
nombre de questions sur le sens et la portée de
l'élection.