bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dominance order and resting site fidelity in the intertidal pulmonate limpetSiphonaria sirius(Pilsbry)
Authors: Iwasaki Keiji 
Published: March 2006

AbstractConsequences of ‘pushing contests’ between pairs of the intertidal pulmonate limpetSiphonaria siriuswere analyzed, focusing on the relationship between dominance order and resting site fidelity. The pushing contests occurred near patches ofEnteromorphasp., their favorite algal food resource. Three or four dominance ranks were determined from the consequences of the contests in different seasons. Individuals in lower dominance ranks tended to shift their resting sites significantly more than those in higher ranks. The dominance order of limpets is considered to play an important role in migration by its effect on resting site fidelity. Density dependent dispersal, from the lower to the upper part of limpets' habitats, was observed in late summer to winter when desiccation was not a problem and food resources became abundant in less populated areas. In late spring to summer, however, migration was directed downwards, from less to more populated areas, where desiccation pressure was relatively weaker. This migration is considered to have a survival advantage, and the behavior of the limpets may have masked density‐dependent dispersal during the two seasons. Distribution of home site was also considered affected by aggressive social behavior during the two periods.
Density‐dependent mortality, growth and size inequality in roadside populations of the annual herbGalium aparineL.
Authors: Puntieri Javier G. , Hall Roger L. 
Published: March 2006

AbstractBiomass, plant size, plant density and the inequality of sizes were assessed for autumn‐emerging roadside populations dominated byGalium aparineduring early stages of growth in two independent studies. A third data set dealt with the survival of labelled seedlings belonging to different cohorts of emergence. One data set showed that the slope of the log‐log size/density relationship for all plant species present in the samples was closer to −1.5 and that forG. aparinewas closer to −1.0 in five separate populations. Biomass increase and density decrease was not found to take place in any of these simultaneously. The size inequality ofG. aparinetended to increase or to remain constant during periods of high mortality, and in the early harvests it was negatively related to population density. The second data set revealed simultaneous decreases of both biomass and density ofG. aparineand of all plant species during a period of a month soon after emergence, and a higher size inequality ofG. aparinein those patches where plant density (and that ofG. aparine) was lower. The labelling of seedlings indicated density‐dependent mortality and a higher probability of survival for seedlings emerging very early. The size/density relationship of roadside populations dominated byG. aparinemay follow a trajectory over time similar to that predicted by the 3/2 power law of self‐thinning, but this species seems to have a weak size hierarchy development and limited individual growth at high population densities. The importance of plant architecture in relation to this response is discussed.
Application of radiotelemetry to the survey of acorn dispersal by Apodemus mice
Authors: Soné Koichi , Kohno Aki 
Published: March 2006

AbstractWe examined the applicability of radiotelemetry to studies of acorn dispersal by Apodemus mice and compared its efficiency with the of this spool‐and‐line method. Installation of a transmitter (2.2 g) onto acorns did not interfere with the transporting and feeding behavior of the mice. We were able to detect all transmitter‐installed acorns and follow the daily changes in the sites in which they were hoarded, while we missed 59% of the spool‐tied acorns due to mice breaking the threads. Mice carried transmitter‐installed acorns farther than spool‐tied ones. The radiotelemetry method is superior to the spool‐and‐line method and useful for the study of hoarding behavior in rodents.
Effects of the common cormorant, phalacrocorax carbo, on evergreen forests in two nest sites at Lake Biwa, Japan
Authors: Ishida Akira 
Published: March 2006

AbstractThe effects of the habitation of the common cormorant on vegetation were evaluated in two colonies in Lake Biwa, central Japan. The state of the vegetation of each colony was classified arbitrarily into the following three types according to the appearance of the tree, shrub and herb layers; dense tree layer (Type 1), sparse tree layer and herb layer (Type 2), and sparse tree layer with dense herb layer (Type 3). The density of cormorant nesting was almost similar among the three types, except for part of Type 2. Trees, especially large ones on which cormorants nested, were found to be heavily damaged, and there were few seedlings and saplings found under the canopy trees. Chamaecyparis obtusa and Cryptomeria japonica were more heavily damaged than other evergreen and deciduous trees. In the herb layer, only a few species such as Reynoutria japonica or Phytolacca americana were abundant. These results suggest that the habitation of cormorants could simplify the structure and the species composition of forests.
Evaluation of the faster initial decomposition of tropical floating leaves of Nymphaea elegans Hook
Authors: Ikusima Isao , Gentil Jóse Geraldo 
Published: March 2006

AbstractContributions of abiotic and biotic processes to the decomposition of floating leaves of Nymphaea elegans were separately evaluated by comparing the rate obtained from an in situ experiment of submerging dry leaf material in a lake, and that from a laboratory experiment of submerging dry leaf material in lake water with a bio‐fixing reagent. It took 8 days to decompose 79.4% of the initial dry weight of the floating leaf of N. elegans in a tropical lake. Of the dry weight loss, 32.9% and 67.1% were atributed to abiotic and biotic decomposition, respectively. The relationship between decomposition rate and the mesh size of the leaf litter bags was examined by the application of a mathematical model. A reasonable value of decomposition loss at an early stage could be obtained using a bag with a mesh opening of 9.9 mm2. The decomposition rate of floating leaves is faster than that of other aquatic plants. Rapid decomposition of N. elegans leaves may be attributed to the fact that the plant has a low carbon to nitrogen ratio.
An experiment on ant predation in soil using a new bait trap method
Authors: Yamaguchi Takeshi , Hasegawa Masami 
Published: March 2006

AbstractTo examine which species of ant are underground predators, we invented a simple bait trap using live mealworms as bait. A total of 75 bait traps were buried in soil at various depths (10, 20, 30 and 50 cm) to investigate the vertical distribution of predatory ants. The ants captured in approximately 50% of the traps were mostly Tetramorium caespitum and Solenopsis japonica. Solenopsis japonica was captured at greater depths (>30 m) than T. caespitum. Eight kinds of soil invertebrate (the earthworm, wood louse, pill bug, millipede, adults of the dung beetle and carabid beetle, larvae of a cetoniine beetle and the earwig), placed in traps at a depth of 10 cm, varied greatly in attractiveness and vulnerability to ant predation. The earthworm and the wood louse were both attractive and vulnerable to ant predation, whereas the pill bug, the dung beetle and the millipede were attractive but not vulnerable. The larvae of a cetoniine beetle, the carabid beetle and the earwig were mostly unattractive.
Analysis of the multi‐stem clump structure of Litsea japonica Juss. growing in a coastal dwarf forest
Authors: Ito Satoshi , Gyokusen Koichiro 
Published: March 2006

AbstractThe multi‐stem clump structure of a coastal dwarf forest dominated by Litsea japonica Juss. was investigated in order to clarify the sprouting characteristics and self‐maintenance of clumps by stem alternation. The size and age distribution of multi‐stem clumps were analyzed using cumulative relative frequency curves. L. japonica had a large number of stems and an even height distribution or young age‐biased distribution of stems within a clump. These results indicated the sequential flushing of sprouts at high frequency. Height distribution within a clump of L. japonica was relatively even compared to other species. This clump structure suggested the stable self‐maintenance of individuals in all ranges of size and age without disturbances. It originated specific sprouting characteristics as a response to the severe stress of salty wind. Ardisia sieboldii Miq. had few stems within a clump. Although the stem height distribution of large individuals tended to be even, most clumps had a large size‐biased distribution of stem height which indicated simultaneous sprouting. From this structure, sprouts of this species were thought to be of less significance in the stable self‐maintenance of individuals than L. Japonica.
Gnawing damage by rodents to the seedlings of Fagus crenata and Quercus mongolica var. grosseserrata in a temperate Sasa grassland‐deciduous forest series in southwestern Japan
Authors: Ida Hideyuki , Nakagoshi Nobukazu 
Published: March 2006

AbstractThe effects of dwarf bamboo, Sasa, cover on the initial morrality of hardwood seedlings were investigated by transplanting 1‐year‐old beech (Fagus crenata) and current‐year oak (Quercus mongolica var. grosseserrata) seedling to three different stands; old‐growth beech and secondary oak forests with Sasa undergrowth, and a Sasa grassland in a grassland‐forest series near the top of Mt Jippo, southwestern Japan. The most frequent cause of seedling morrality was gnawing of the stems by rodents. In the beech forest, the gnawing was more likely to occur under Sasa cover, suggesting that it provides a good habitat for rodents on the beech forest floor. The Sasa under growth may thus play an imporrant role in regeneration of beech forest. In the oak floor, mortality of both species was low and only a little gnawing occurred during a year. However, no natural oak seedling were found in the forest even after a mast year. This may be because most of the acorns disappeated before establishment. The early‐stage demography of hardwood seedling as oak may thus play an imporrant role in regeneration of oak forest. In the Sasa grassland where the seed supply is small, almost all of the seedlings died fromo gnawing regardless of the presence of Sasa cover. These factors prevent the recruitment of a sizable seedling bank. Rodents may thus play an imporrant role in maintenance of the Sasa grassland.
The impact of intralacustrine introductions with regard to space utilization and competition for territories to a cichlid fish community in Lake Malawi, Africa
Authors: Hert Eva 
Published: March 2006

AbstractAt Thumbi Island West in Lake Malawi, a number of cichlid species was introduced from elsewhere in the lake some 20 years ago. These are now, in part, well established and could have an effect on the indigenous fish fauna. Repeated removals of the males of the introduced species from their territories were undertaken and artificial miniature reefs were established to find out whether the emptied existing territories or the newly established potential territories would be occupied by indigenous species. The results show that the emptied territories were almost invariably re‐occupied by either a male of the introduced species conspecific to the previous territory holder or they remained empty. The newly established miniature reefs were not occupied by territorial males of either introduced or indigenous species but by young fish of a variety of species.
Distribution of hydraulic resistance in seedlings, sprouts and an adult tree of Pasania edulis Makino
Authors: Ito Satoshi , Sakuta Kotaro , Gyokusen Koichiro 
Published: March 2006

AbstractHydraulic resistance is an important factor in predicting water status. Hydraulic resistance of petiols, stems and branches, and roots was measured in Pasania edulis Makino in order to compare the distribution of resistance between current seedlings, current stump sprouts and a 16 year old adult tree. Total resistance showed only minor variations despite large variations in plant size. This result is thought to be consistent with allometry between leaf mass and supportive organ mass, and with changes in permeability of conductive organs. Root resistance was low in sprouts and the adult tree due to their mature root systems. Current seedlings with undeveloped root systems had high root resistance. The proportion of petiol resistance in total resistance was high compared to the proportion of their conductive distance, and was thought to be a limiting factor of tree water status. The petiol resistance of the adult tree leaves was higher than for seedling and sprout leaves. From a comparison with the leaf water relation characteristics, the petiol resistance was thought to be provided as low values for intolerant leaves against water stress in order to compensate water inflow, and high values for tolerant leaves to regulate water inflow.
Fluctuation of nut production and seedling appearance of a Japanese beech (Fagus crenata Blume)
Authors: Hiroki Shozo , Matsubara Teruo 
Published: March 2006

AbstractThe nut productivity, density of fallen nuts, seedling appearance and seedling survival of a Japanese beech (Fagus crenata Blume) were investigated at three localities, Mt Gozaisho, Mt Hodaka and Mt Bandai, Japan, from 1976 to 1992. Two patterns of cycles, a short cycle and a long one, were confirmed in the beech nut productivity. Synchronization in the long cycle was recognized both on Mt Hodaka and Mt Bandai. On Mt Gozaisho, the beech nut productivity was quite low, and the seedlings disappeared within 1 year. The phenomenon on Mt Gozaisho seemed to be caused by the low matter production mainly due to erosion and poor soils. A large number of seedlings appeared in the next spring of heavy mast years on Mt Hodaka and Mt Bandai. The large beech nut productivity contributed to the large seedling supply, and this enhanced the survival probability of beech seedlings. This demonstrates the possibility that beech seedlings survived longer even under dense dwarf bamboos, particularly if the seedling supply was large.
Factors limiting the distribution of the annual legume Kummerowia striata in a river floodplain
Authors: Nakatsubo Takayuki 
Published: March 2006

AbstractThe annual legume Kummerowia striata often predominates in river floodplains forming a large population, but it is rare in gravelly areas adjacent to it. In order to clarify the factors limiting the distribution of K. striata, its distribution pattern, germination and survival of seeds sown artificially were studied in the floodplain of the Ohta River. There was a positive correlation between the cover value of K. striata and the percentage of fine particles (<0.2 mm) in the soil. In the winter season, there was a number of seeds (up to 47 seeds 20 cm−2) on the ground where a K. striata population had existed in the previous year, but they were very sparse in areas apart from the population. Only a small proportion of seeds sown in the gravelly area germinated. Many of the germinated individuals died before the first leaf unfolded, but the rest survived to maturity despite repeated floodings. Plants germinated in the gravelly area and those inoculated with soil from the gravelly area bore nodules, showing the presence of Rhizobium in the gravelly area. It was concluded that the colonization of K. striata in the gravelly area was limited by slow dispersal, and by a low percentage of germination and high mortality in the early stage of establishment.
Seasonal changes in the Modulus of Elasticity of living branches of three coniferous species
Authors: Onwona‐Agyeman Siaw , Morioka Noboru , Kondo Minoru , Kitagawa Katsuhiro 
Published: March 2006

AbstractThe seasonal changes in the Modulus of Elasticity (E) of living branches of Cryptomeria japonica, Chamaecyparis obtusa and Larix leptolepis were investigated over a period of 1 year by means of a quick and non‐destructive method previously introduced by the authors. Two sample trees were used for each species and 12 branches were selected from each tree. Readings of the experiments began in summer 1992 and were successively conducted in autumn 1992, winter 1993, spring 1993 and finally in summer 1993. Our investigations revealed that mean E values increased in cold seasons and decreased in warm or hot seasons. Mean values of E estimated in summer (1993) were relatively close to those estimated in summer 1992 indicating that any changes that occurred were the direct result of the environmental factors prevailing in the intervening seasons. Extremely high mean E values were measured when the branches were in a frozen state in winter; 69.4%, 29.9% and 24.6% higher than the previous summer for branches of Cryptomeria japonica, Chamaecyparis obtusa and Larix leptolepis, respectively. This sharp increase over the initial E values measured in summer 1992 was quite likely due to the freezing effect of rime on the branches.
The effect of growth form on the evaporation in some subalpine mosse
Authors: Nakatsubo Takayuki 
Published: March 2006

AbstractIn order to evaluate the importance of growth of mosses in controlling evaporative water loss, the evaporation rates of some subalpine moss species of various growth forms were compared with each other. The growth forms of the xerophytic species examined were large cushion and compact mat, while those of the mesophytic species in the coniferous forest floor were smooth mat, weft and tall turf. The evaporation rate per moss dry weight (Ew) was much smaller in the xerophytic species than in the mesophytic species. However, the evaporation rate per basal area of moss colony (Ea) was not necessarily smaller in the xerophytic species. The relation between Ea and dry weight per basal area of the colony (Wa) had a close correlation with the growth form. It was concluded that the difference in the evaporation rate per weight between the exerophytic species and the mesophytic species was largely due to the difference in Wa, and that the growth forms of the xerophytic species were suitable for increasing Wa without increasing surface roughness.
Topographical pattern of the forest vegetation on a river basin in a warm‐temperate hilly region, central Japan
Authors: Sakai Akiko , Ohsawa Masahiko 
Published: March 2006

AbstractThe relationship between tree distribution and topography was examined in a small river basin (3.4 ha) comprising a complex mosaic of topographical units at 102 to 103 m2 order, each of which had a shallow valley bordered by small ridges or breaks of slopes. Twenty‐five major woody species were divided into two groups (groups A and B) based on a cluster analysis using the distribution data in the basin. Group A, which mainly consisted of early‐successional species, was distributed around the valley sites of the topographical units, while group B, which mainly consisted of late‐successional species, was distributed around the ridge sites of the topographical units. This vegetation pattern coincided with erosional condition in the basin. That is, the valley sites were eroded more actively than the ridge sites, as soil depth tended to be thin in the valley sites and thick in the ridge sites, and because large (canopy) trees were restricted in the ridge sites. There was no tendency that group B was replacing group A, and hence it was suggested that repeated disturbance by slope failures or small‐scale shallow landslides have prevented compositional change from the early‐successional (group A) to the late‐successional (group B) species by preventing the invasion of the latter into valley sites.
Gap regeneration in primary evergreen broad‐leaved forests with or without a major canopy tree, Distylium racemosum, southwestern Japan: A comparative analysis
Authors: Yamamoto Shin‐Ichi 
Published: March 2006

AbstractGap regeneration was studied in a typical primary evergreen broad‐leaved forest without Distylium racemosum, at the Kasugayama Forest Reserve, southwestern Japan and the results were compared with those from other primary evergreen broad‐leaved forests in southwestern Japan, where D. racemosum was the dominant species. Several common types of gap regeneration behavior were recognized among the major tree species and forests with or without D. racemosum consisted of three typical regeneration guilds which could be detected in the principal component analysis. Castanopsis cuspidata frequently regenerated in gaps from saplings recruited before gap formation in the forest without D. racemosum, although elsewhere, in forests with D. racemosum, it lacked advanced regeneration and regenerated in gaps from saplings recruited after gap formation. Some evergreen Quercus had their regenerations in gaps of the forest without D. racemosum, although elsewhere, in forests with D. racemosum, evergreen Quercus might not regenerate. The results indicate that tree species may change their regeneration behavior depending on the presence or absence of another key dominant species. This suggests that the presence and the dominance of a potential competitor induces shifts in the regeneration niche of other coexisting tree species.
Vegetation structure along the altitudinal gradient at the treeline of Mount Paektu, North Korea
Authors: Šrůtek Miroslav , Kolbek Jiří 
Published: March 2006

AbstractVegetation structure of the treeline was studied on the southeastern slope of Mount Paektu (North Korea). Fifteen temporary plots (20m×20m) were situated along the altitudinal transect. Seven square samples (phytosociological relevés 5 m×5 m) were analyzed in each plot. Although the character of the vegetation was rather continuous altitudinally, five similar groups of vegetation samples were distinguished by the TWINSPAN procedure. The distribution of samples in the classification showed not only the effect of altitude but also the effect of competition between the tree and the shrub layers and other factors. In the canonical correspondence analysis (CCA) ordination several environmental variables were used (such as altitude of each plot, distance of each plot from the forest edge and the cover percentage of tree, shrub, herb and moss/lichen layers). The variable ‘cover of tree layer’ had the strongest relation to the species data. Continuous changes of species richness along the altitude were confirmed. Species richness decreased significantly with altitude.
Tropical fruitflies (Diptera: Tephritidae) of the Krakatau Archipelago in 1990 and comments on faunistic changes since 1982
Authors: Schmidt E. R. , Thornton I. W. B. , Hancock D. L. 
Published: March 2006

AbstractThree of the Krakatau islands, in Sunda Strait, some 40 km from both Java and Sumatra, are believed to have been totally devastated by the famous cataclysmic eruption of 1883. The fourth, Anak Krakatau, is an emergent volcanic island which rose from Krakatau's submerged 1883 caldera in 1930, suffered a self‐devastating eruption in 1952/3 and several severely damaging ones since then. In 1990 the tephritid fauna was monitored on all the islands with Steiner traps. Nine species were found, five of which appeared to have been found by Yukawa in 1982 (Yukawa 1984) using similar methods and lures, when he noted a total of six species. As in 1982, the fauna in 1990 was characterized by the numerical dominance of Bactrocera albistrigata (de Meijere) although this appeared to be less marked than in 1982 and Bactrocera papayae Drew & Hancock appeared to have increased in relative numbers. The distribution of three species over the islands of the archipelago had increased and four species not found in 1982 were present. Rakata, Krakatau's remnant and by far the largest and highest island, carried seven species (six in 1982), Sertung three (two in 1982), Panjang four (one in 1982) and Anak Krakatau four (one in 1982). Capture rates were lower than in 1982 but still higher than those obtained on the Javan mainland in 1982. There was a marked difference between the tephritid faunas of Anak Krakatau's two forelands, which were at different stages of biotic succession.