bluuebunny/crossref_metadata_2025_split huggingface dataset:
Canonical correspondence analysis of early volcanic succession on Mt Usu, Japan
Authors: Tsuyuzaki Shiro , del Moral Roger 
Published: March 2006

AbstractCanonical correspondece analysis (CCA) was applied to explore revegetation patterns during early succession on Mt Usu. Vegetation was buried by deposits of ash and pumice from 1 to 3 m in depth from the 1977–78 eruptions. Three habitats were selected: tephra, tephra in gully and original surface. Plant density and plant cover data were analyzed separately. Environmental factors consisted of five quanticative variables (organic matter, elevation, distance from colonizing source, erosion and deposition of volcanic deposits) and three nominal variables (habitat types: tephra, tephra in gully and original surface). Canonical correspondence analysis showed that the original surface played a special role in vegetation development because the old topsoil supplied both nutrients and seed‐bank species. The CCA also suggested that the environmental factors that influence plant density and cover differ. Distance from colonizing source affected plant density while erosion affected cover. Using CCA, factors could be distinguished that influenced seedling establishment from vegetation expansion and vegetation recovery dynamics could also be more clearly interpreted.
Successional leafhopper assemblages: Pattern and process
Authors: Hollier J. A. , Brown V. K. , Edwards‐Jones G. 
Published: March 2006

AbstractAuchenorrhyncha (leafhopper) faunas of a series of experimental plots of different successional age were recorded by vacuum sampling. There were clear successional trends in the assemblages. The life‐history strategy of the dominant species changed during succession; the mobile and multivoltine or bivoltine species, which overwinter as adults or nymphs, are replaced by less active, univoltine or bivoltine species which overwinter as eggs. Leafhopper assemblages clearly responded to the changes in plant species composition and vegetation structure during succession; however, disentangling the relative importance of the various factors requires further experimental manipulation.
Prey selection by a spider wasp,Batozonellus lacerticida(Hymenoptera: Pompilidae): Effects of seasonal variation in prey species, size and density
Authors: Endo Tomoji , Endo Akira 
Published: March 2006

AbstractPrey selection by a spider wasp,Batozonellus lacerticida, was investigated at the riverside of the Toyohira River in Misumai, Sapporo, Hokkaido over 7 years from 1981 to 1987. Seventeen species of araneid spiders were found in the study area and six of them were hunted by the wasps. Most (97.3%) of the 223 prey records obtained were of three species,Araneus macacus, A. marmoreusandA. pinguis. Nesting activity of the wasps continued until mid‐August in 1981, 1982 and 1986, but stopped in July in 1984, 1985 and 1987. The length of nesting period was related to whether the wasps successfully switched prey species fromA. macacustoA. marmoreusandA. pinguisandA. pinguisor not Switching seemed to occur at the phase when density ofA. macacusremained high, depending on the density of largerA. marmorusandA. pinguis. This switching had large effects on species composition and size distribution of actual prey. Chesson's index α calculated at every 10 day period revealed that the wasps preferredA. macacusto the two other species and large prey to medium and small ones. The effect of prey density on preference depended on whetherA. macacuswas present or absent. In the presence of it there were only slight differences in preference among various conditions of prey density. However, whenA. macacuswas absent, densities of bothA. marmoreusandA. pinguishad some complementary effects on preference. The importance of prey size selection by pompilid wasps, and implications of density effects on preference are discussed.
Photoperiodic control of larval development in the semivoltine cockroach Periplaneta japonica (Blattidae: Dictyoptera)
Authors: Shindo Jun‐ichi , Masaki Sinzo 
Published: March 2006

AbstractPeriplaneta japonica is semivoltine, entering early diapause in any (except the first) larval instar before the last, and late diapause in the last instar. Early diapause was induced under a short day of 13 h or less at 28°C, and under both short and long daylength (12–16 h) at 20°C. The shorter the daylength and the lower the temperature, the younger the instar was entering early diapause. Early diapause was terminated by a long day (16 h) or a high temperature (28°C), after which larvae grew faster in short days than in long days until the last instar, when they again entered diapause, always in short days and frequently in long days. This late diapause was terminated also by an increase in daylength and was always followed by adult emergence. In this case, 13 and 14 h daylengths after exposure to 12 h daylength were as effective as 16 h daylength. Ourdoor samples collected in late autumn, winter and early spring at Hirosaki (40.5°N) comprised two distinct size groups, corresponding with the early and late diapause instars. Based on these results, the seasonal development strategy and intriguing aspects of the photoperiodic response in this cockroach are discussed.
Stand structure and carbon metabolism of coppice forests at a heavy snowfall climate region of central Japan. I. Dynamics of stand structure during 14 years
Authors: Yoneda Tsuyoshi , Hamabata Etsuji , Ogawa Husato 
Published: March 2006

AbstractThe coppice stands under the climatic conditions of Warmth Index (WI)≧85°C·month, and Coldness Index (CI)≦−10°C·month could be classified into a Quercus serrata type and Carpinus types at a heavy snowfall climate region of central Japan. The latter types tended to be more distributed on steeper slopes rather than the former. An analysis of tree forms and growth rates of species could reveal the characteristic of this habitat and vegetation type. The growth rates of stem diameter of dominant species on a gentle slope were higher than ones on a steep slope. However, the dominant species on the steeper slope had plasticity to basal bend with sustentacular roots, which is one form of tolerance of heavy snowfall on steep slopes. Average mortality during 14 years was 26%, irrespective of the gradient of a slope. More than one‐third of dead shoots were induced by direct damage, while cracked or broken pieces of a stem were from heavy snowfall. The shoot density at smaller diameter classes tended to be higher at a stand having high horizontal variance of canopy surface caused by basal bend of big shoots. A frequency distribution function of individual tree weight (w), f(w)=pw−3/2, could be obtained at each coppice stand by statistical analysis. The value of a parameter p, a packing factor, tended to be higher at stands on steeper slopes consisting of largely bent shoots and was constant irrespective of the growth.
Comparative study of leaf carbon gain in saplings of Thujopsis dolabrata var. hondai and Quercus mongolica var. grosseserrata in a cool‐temperate deciduous forest
Authors: Hashimoto Ryoji , Shirahata Manabu 
Published: March 2006

AbstractSeasonal courses of leaf CO2 gas exchange in a growing season were examined in saplings of Thujopsis dolabrata var. hondai and Quercus mongolica var. grosseserrata in a cool temperate deciduous forest. Between the two tree species there were no large differences in the light compensation point of leaf photosynthesis, except for the season of new leaf expansion. However, light‐saturated rates of net photosynthesis were obviously high in T. dolabrata var. hondai. Evergreen T. dolabrata var. hondai saplings had large photosynthetic production in two seasons, before the emergence of new foliage and after foliage fall of the overstory deciduous trees, because of the significantly high solar radiant energy penetrating under the forest canopy during the seasons. Saplings of deciduous Q. mongolica var. grosseserrata were heavily shaded throughout the growing season by foliage of the overstory trees, which resulted in a low daily surplus production. The annual surplus production of leaves in the growing season was estimated to be 2300 mmol CO2 m−2 in T. dolabrata var. hondai and −100 mmol CO2 m−2, slightly negative, in Q. mongolica var. grosseserrata. These results supported the high survivability of T. dolabrata var. hondai saplings and the high mortality of Q. mongolica var. grosseserrata in the deciduous forest.
Sex expression, sex change and fruiting habit in an Acer rufinerve population
Authors: Matsui Kiyoshi 
Published: March 2006

AbstractThree hundred and thirty‐eight plants of Acer rufinerve Sieb. et Zucc. were monitored in a secondary deciduous forest for 5 years in terms of their sex expression and fruiting habit. Two types of flowers, functionally male and female, were recognized. The adult population consisted of constant males, inconstants and constant females. Constant males, plants that bore exclusively male flowers throughout the study period, accounted for 87% of the adult population. Thirty‐four inconstant plants (11%) changed their sex in various ways. Constant females which accounted for only 2% of the population, were significantly smaller plants than the other two morphs, and suffered greater mortality. Fruit set was consistent and generally high for plants bearing female flowers. Thirteen juvenile plants out of 17 began reproduction during the 5 years, and all became male. For inconstant plants, fluctuation in sex expression tended to be more frequent and/or greater in magnitude for smaller plants. However, there was no evidence of the directional sex transition predicted by the size advantage hypothesis. Plant health and the successional stage of the stand should be taken into account as well as resource allocation problems to explain the proximate mechanisms of sex expression.
Effect of competitor abundance on feeding territoriality in a grazing fish, the ayu Plecoglossus altivelis
Authors: Iguchi Kei'ichiroh , Hino Teruaki 
Published: March 2006

AbstractThe grazing fish, ayu, Plecoglossus altivelis Temminck & Schlegel, establishes feeding territorialiry during the young stage. The population density fluctuates from year to year by more than a hundredfold, but the determinant of territory size is less well known. The feeding territoriality of ayu was examined under simulated habitat conditions where fish density was manipulated and food resources were renewable. Fish competed for algae attached to the substrata and were divided into residents with territories, and floaters without territories. By experimental alteration of fish density the number of residents increased with density and rerritory size decreased with density. Floaters intruded into territories in a school to feed on algae, which induced overt aggression of the resident and reduced the productivity of algae growing there. Both the intruding frequency of floaters over territorial areas and their feeding pressure on algae increased at higher floater density. Floaters functioned to shift cost‐benefit relationships for various territory sizes. They acted as food competitors to restrict territory size below a maximum through competitive interference. Although the growth rate of residents was inversely related to fish density, residents grew faster than floaters in each group. Under a given set of competitor abundances, economic defensibility determined territory size.
Spatial structure of avifauna along urban‐rural gradients
Authors: Natuhara Yosihiro , Imai Chobel 
Published: March 2006

AbstractWe examined the pattern of species composition of breeding birds along urban‐rural gradients in the Osaka Prefecture, western Japan. We recorded the proportion of nine types of land‐use and the presence/absence of each of 76 breeding birds in 5 km square quadrats on a map of the Prefecture. The proportion of woodland and farmland which increased from urban to rural areas were two major enviornmental gradients according to Principal Component Analysis of the nine types of land‐use. Ordination by Canonical Correspondence Analysis (CCA) showed that the breeding bird distribution differentiated along the two major clines, woodland and farmland. The avifauna changed successively along these environmental gradients. There were no discrete boundaries of the distribution of bird species groups. We tentatively classified five groups of quadrats on the ordination plane of the sample score. The geographic position of these five groups on a map preserved the environmental gradient, but showed that water (seashore and river) was a stronger influence on bird species composition than land‐use pattern. Although the diversity of land‐use seemed to raise species richness in the third group, the less diverse, woodland‐rich group contained as many species as the third group. Four groups of bird species, and one group in which species occurred in more than 90% of the quadrats, were classified in the CCA‐ordination plane. The occurrence of these bird groups correlated with land‐use; the first group with woodland area, the second with scatter woodland, the third with farmland and the fourth with seashore.
Stand dynamics during a 12 year period in an old‐growth, cool temperate forest in northern Japan
Authors: Namikawa Kanji 
Published: March 2006

AbstractIn 1979 and 1991, trees over 2.0 m high were measured and mapped together with their crown projections to clarify stand dynamics and shifts in canopy dominants during this period, in a permanent plot of 0.525 ha in an old‐growth, cool temperate mixed forest of Mt Moiwa, Central Hokkaido, northern Japan. During this period, an abundant recruitment of trees was observed after some canopy trees were felled by a typhoon in 1981 leaving gaps in the canopy. Vigorous recruitment was observed for Tilia japonica, Acer mono and Prunus ssiori. These species had different regeneration sites in relation to canopy state. Neither Ulmus japonica nor Kalopanax pictus had any recruits during the 12 year period even in gaps. The equilibrium composition of tree species projected from transition probability analysis also implied the above shift of dominant species during the 12 year period in the plot and suggested that the present forest is not in an equilibrium state.
Soil macro‐invertebrates and litter disappearance in a Japanese mixed deciduous forest and comparison with European deciduous forests and tropical rainforests
Authors: Tsukamoto Jiro 
Published: March 2006

AbstractSoil macro‐invertebrates and rate of litter disappearance were studied in a ridge plot with moder (mor) humus and a bottom plot with mull humus on a slope in a temperate mixed deciduous forest in Kyoto, Japan (J). The results were compared with those from two German beech forests (G) representative of European deciduous forest mor and mull. Between‐plot differences in biomass of total saprophagous animals was much smaller in J than in G, which is dominated by earthworms. Susceptibility to soil acidity and zoogeographical distribution of earthworms were suggested to be related to this situation. Biomass of soil macro‐invertebrates and litter turnover rate were compared among J, G and three types of tropical rainforests in Malaysia (M) in relation to climatic conditions. Taking into account among‐site differences in temperature and moisture, which affect microbial activity and in biomass of saprophagous macro‐invertebrates especially earthworms, the following order of importance of soil macro‐invertebrates in determining the rate of litter disappearance was suggested: G>J>M. Based on the comparison of biomass of earthworms among European deciduous forests, Japanese deciduous forests and tropical rainforests, as well as on the presence or absence of anecic earthworms in these forests, it was suggested that this ranking could be generalized to European deciduous forests > Japanese deciduous forests > tropical rainforests. It was pointed out that this order was the opposite of the gradient in evapotranspiration rate existing among these regions.
Age‐specific life history tactics in organisms with determinate growth: Optimal models for non‐optimal behavior?
Authors: Thomson David L. 
Published: March 2006

AbstractAmong organisms with determinate growth, optimization models predict that reproductive effort should increase as individuals approach old age, but the assumptions of these models may be inappropriate because the senescence that generates the necessary selective pressure may be not itself be optimal. Population genetics models were constructed to examine whether genes for age‐specific changes in reproductive effort could invade a population in which senescence was maintained at equilibrium levels by a balance between mutation and selection. In asexually reproducing organisms, it was found that strategies of increasing reproductive effort could not normally invade the population. In sexually reproducing organisms, however, recombination was found to be important and genes for age‐specific changes in effort could spread in the population under most circumstances.
A model of litter harvesting by the Western Australian wheatbelt termite, Drepanotermes tamminensis (Hill), with particular reference to nutrient dynamics
Authors: Park H. C. , Orsini J. P. G. , Majer J. D. , Hobbs R. J. 
Published: March 2006

AbstractA series of papers have been published which describe the influence of vegetation and soil type on the Western Australian wheatbelt termite, Drepanotermes tamminensis (Hill), and also on its litter harvesting levels and contribution to the soil nutrient budget. This paper integrates these findings by means of a computer simulation model. The model consists of three modules which respectively describe the dynamics of litter on the ground, the dynamics of litter within termite mounds and how these in turn influence nutrient loads within the habitat. The outputs of the model suggest that this litter harvesting termite plays an important role in the nutrient dynamics of the area and it provides an estimate of the unmeasured variable, litter consumed in mounds by termites, which is consistent with measurements for other termite species with similar feeding habits.
Reconstruction of Ropalidia fasciata nests by progeny females after a typhoon and its significance in the social evolution of wasps
Authors: Itô Yosiaki 
Published: March 2006

AbstractA strong typhoon, Typhoon 13, which swept through Okinawa on 2 and 3 September 1993, knocked down 57 to 61 of 97Ropalidia fasciata nests. Thirty‐five colonies soon reconstructed their nests, and these nests produced 54±46 adults per nest during the remaining two and a half months before winter. The number of females involved in nest reconstruction was 21.3±15.7 per nest. The frequency of foraging activity was significantly higher in nests being reconstructed than in normal nests. As only one out of 205 foundresses marked in spring was found in early September, most cases of nest reconstruction were considered to be made exclusively by females that emerged during the spring and summer of 1993 (progeny females). All of the reconstructed nests but one produced adult females. Many females (31%) collected from the two reconstructed nests were inseminated. As all the reconstructed nests became vacant by early January, indicating completion of the colony cycle, and a large number of nests were established in the spring of 1994, females emerging from reconstructed nests in 1993 probably become foundresses in 1994. Ropalidia fasciata is considered to be, at least partially, bivoltine in Okinawa. The significance of these facts for the evolution of multi‐queen social systems in the Polistinae is discussed.
Food habits of sika deer on the Boso Peninsula, central japan
Authors: Asada Masahiko , Ochiai Keiji 
Published: March 2006

AbstractThe rumen contents of sika deer (Cervus nippon Temminck) on the Boso Peninsula, central Japan, were analyzed to identify local, sexual and age‐specific differences in food habits. Graminoids and woody plants were the primary foods throughout the year. In winter, the use of evergreen broad leaves increased. The food habits of sika deer on Boso Peninsula were intermediate between those of populations inhabiting northern and southern Japan. Acorns, mainly Lithocarpus edulis Nakai, were consumed in fall and winter with a peak in October. Since the availability of acorns is not influenced by foraging in previous years, it can be regarded as a stable food supply and hence may be important for deer on the Boso Peninsula. The local difference between the Amatsukominato (AT) area, having a large plantation of Lithocarpus producing acrons, and the Kamogawa‐Katsuura (KK) area, having a small plantation of Lithocarpus, was recognized; seeds and fruit were consumed more in AT than in KK in fall and winter. Males consumed more seeds and fruit than females at both sites in fall. This can be attributed to sexual differences in nutritional requirement.
Effects of disturbance and size structure on the regeneration process in a sub‐boreal coniferous forest, northern Japan
Authors: Kubota Yasuhiro 
Published: March 2006

AbstractThe stand structure and disturbance history in a sub‐boreal coniferous forest dominated by Picea jezoensis, Picea glehnii and Abies sachalinensis were investigated in four study plots set up in Taisetsuzan National Park, Japan. The effect of stand characteristics on the growth and mortality rates of understory trees was examined. Although all the stands showed inverse J‐shape d.b.h. (diameter at breast height) distributions, the age structure and disturbance history differed amongst the stands. The stands with wide d.b.h. distribution (i.e. large CV and skewness) were more uneven‐aged than those with narrow d.b.h. distribution (i.e. small CV and skewness). The disturbance‐return interval based on the model of Hett and Loucks was 31 to 65 years. The gap ratio in the canopy was also different among the stands. These suggest that the variations in stand structure represent different occurrences of natural disturbances. Furthermore, the structural features such as size structure, canopy gap ratio and density of canopy trees also affected the growth dynamics of understory trees (≥2 m in height and <10 cm in diameter at breast height). The growth and mortality rates of understory trees changed with the canopy gap ratio and canopy tree density. The understory trees of stands with wide canopy d.b.h. distribution had higher growth and canopy recruitment rates than those of stands with narrow canopy d.b.h. distribution, contributing to the maintenance of continuous stand stratification. The understory trees of stands with narrow canopy d.b.h. distribution showed lower growth and higher mortality rates than those of stands with narrow canopy d.b.h. distribution, leading to the formation of a single‐canopy structure. It is suggested that natural disturbance governs the regeneration process in the future by affecting the growth and mortality patterns of understory trees through the stand structure (size and age structure, canopy tree density, canopy gap ratio).
The pollination ecology of Bletilla striata (Orchidaceae)
Authors: Sugiura Naoto 
Published: March 2006

AbstractAnthecological observations of an orchid Bletilla striata were carried out in Kobe, Japan. The purplish pink flowers were visited by 26 species of insects belonging to Hymenoptera, Diptera and Lepidoptera, although the flower did not offer food rewards of any kind. Candidates for pollination were seven species of aculeate Hymenoptera with a body size that well fitted the space in between the column and labellum. The most effective candidate was the male of the longhorn bee Tetralonia nipponensis, judging from its abundance and legitimate intrafloral behavior. The female of T. nipponensis and the other six species also contributed to promote out‐crossing, but to a lesser extent than the male T. nipponensis, since they occasionally exhibited illegitimate intrafloral behaviors for pollination and also, their flower visitation rate was lower.