Iwata T.,Yamanashi University |
Urabe J.,Tohoku University |
Mitsuhashi H.,Museum of Nature and Human Activities
Conservation Biology | Year: 2010
Interfaces between terrestrial and stream ecosystems often enhance species diversity and population abundance of ecological communities beyond levels that would be expected separately from both the ecosystems. Nevertheless, no study has examined how stream configuration within a watershed influences the population of terrestrial predators at the drainage-basin scale. We examined the habitat and abundance relationships of forest insectivorous birds in eight drainage basins in a cool temperate forest of Japan during spring and summer. Each basin has different drainage-basin geomorphology, such as the density and frequency of stream channels. In spring, when terrestrial arthropod prey biomass is limited, insectivorous birds aggregated in habitats closer to streams, where emerging aquatic prey was abundant. Nevertheless, birds ceased to aggregate around streams in summer because terrestrial prey became plentiful. Watershed-scale analyses showed that drainage basins with longer stream channels per unit area sustained higher densities of insectivorous birds. Moreover, such effects of streams on birds continued from spring through summer, even though birds dispersed out of riparian areas in the summer. Although our data are from only a single year, our findings imply that physical modifications of stream channels may reduce populations of forest birds; thus, they emphasize the importance of landscape-based management approaches that consider both stream and forest ecosystems for watershed biodiversity conservation. © 2010 Society for Conservation Biology.
Akiyama H.,Museum of Nature and Human Activities |
Goffinet B.,University of Connecticut
Journal of Bryology | Year: 2011
Indopottia irieandoana H.Akiyama sp. nov. is reported on the basis of two specimens from Doi Inthanon, northern Thailand, as a second species of a genus recently described from southern India. The lack of a peristome precludes unambiguous familial placement based on morphology, but phylogenetic analyses of sequences from a chloroplast and a mitochondrial locus place the new taxon, with strong support, in the Pottiaceae. Its epiphytic habitat on a tree trunk and a branch near the crown of an emergent tree and a strangler tree, respectively, along with morphological features such as spatulate leaves, a single dorsal stereid in the leaf costa, smooth laminal cells, long rostrate opercula, and eperistomate, upright capsules point to a close relationship to Indopottia zanderi. The morphology is compared with that of related genera. A key to similar genera and species is provided. © British Bryological Society 2011.
Osawa T.,Japan National Institute for Agro - Environmental Sciences |
Kohyama K.,Japan National Institute for Agro - Environmental Sciences |
Mitsuhashi H.,Museum of Nature and Human Activities
PLoS ONE | Year: 2013
Human-driven land-use changes increasingly threaten biodiversity. In agricultural ecosystems, abandonment of former farmlands constitutes a major land-use shift. We examined the relationships between areas in which agriculture has been abandoned and the distribution records of threatened plant species across Japan. We selected 23 plant species that are currently identified as threatened but were previously common in the country as indicators of threatened plant species. The areas of abandoned farmlands within the distribution ranges of the indicator species were significantly larger than the proportion of abandoned farmland area across the whole country. Also, abandoned farmland areas were positively correlated with the occurrence of indicator species. Therefore, sections of agricultural landscape that are increasingly becoming abandoned and the distribution ranges of indicator species overlapped. These results suggest that abandoned farmland areas contain degraded or preferred habitats of threatened plant species. We propose that areas experiencing increased abandonment of farmland can be divided into at least two categories: those that threaten the existence of threatened species and those that provide habitats for these threatened species. © 2013 Osawa et al.
Takano A.,Museum of Nature and Human Activities |
Okada H.,Osaka City University
Journal of Plant Research | Year: 2011
To determine evolutionary relationships among all Japanese members of the genus Salvia (Lamiaceae), we conducted molecular phylogenetic analyses of two chloroplast DNA (cpDNA) regions (rbcL and the intergenic spacer region of trnL-trnF:trnL-trnF) and one nuclear DNA (nrDNA) region (internal transcribed spacer, ITS). In cpDNA, nrDNA, and cpDNA+nrDNA trees, we found evidence that all Japanese and two Taiwanese Salvia species are included in a clade with other Asian Salvia, and Japanese Salvia species were distributed among three subclades: (1) S. plebeia (subgenus Sclarea), (2) species belonging to subg. Salvia, and (3) species belonging to subg. Allagospadonopsis. At the specific level our findings suggest: a close relationship between S. nipponica and S. glabrescens, no support for monophyly of S. lutescens and its varieties in cpDNA, nrDNA and cpDNA+nrDNA trees, and that S. pygmaea var. simplicior may be more closely related to S. japonica than to other varieties of S. pygmaea. © 2010 The Botanical Society of Japan and Springer.
Kodate S.,Museum of Nature and Human Activities
Nature and Human Activities | Year: 2013
The topography, vegetation and soil properties were investigated in a stand of red pine (Pinus densiflora Sieb. et Zucc.) forest on a ridge-shaped slope in Sanda City, Hyogo Prefecture. The purpose of this study is to clarify the relationship between the degree of damage of the forest from the pine wilt disease and environmental and topographic factors, such as the position on the slope and the maximum capillary-water capacity of the soil. The degree of elongation growth of the red pine tended to be smaller on the upper part of the slope than the lower part. There was also a tendency of more frequent, severer pine root die-back damage on the lower part of the slope than the upper part. The total basal area was higher in plots with severe pine wilt damage than in other plots. The soil in the investigated area was thin in effective depth and poor development. The soil water-repellency was weaker in plots with severe pine wilt damage than in the other plots. Plots with severe damage from the pine wilt disease had a better soil moisture environment than the other plots. Resistance of the red pine to the dryness was weak, and trees that had developed in a good moisture environment appeared prone to root desiccation during periods of extraordinary summer dryness.
Uematsu Y.,Kobe University |
Koga T.,Kobe University |
Mitsuhashi H.,Museum of Nature and Human Activities |
Ushimaru A.,Kobe University
Agriculture, Ecosystems and Environment | Year: 2010
Although traditional agricultural land use maintains biodiversity, recent land-use changes involving abandonment or use intensification have rapidly reduced the biodiversity of agricultural landscapes. Organisms living in agricultural landscapes are likely to respond differently to these changes, with some species declining rapidly and others remaining unchanged. However, few studies have focused on this interspecific difference in susceptibility to land abandonment and intensification in agricultural landscapes. We hypothesize that rarer herb species are more susceptible to both abandonment and intensification than are common herbs due to habitat preferences in the semi-natural grasslands of agricultural landscapes. To test this hypothesis, we examined the distributions of two pairs of congeneric grasslands species on abandoned and consolidated (production-intensified) paddy fields to assess differences in vulnerability to paddy abandonment and consolidation between the rarer and the more common species in an agricultural landscape. We found that higher, steeper fields farther from roads in the upper areas of paddy terraces were more frequently abandoned in our study area. The two rarer species had significantly more overlap with the distribution of fields at risk of abandonment than did the two more common congeneric species. In addition, the two rarer species were significantly less widely distributed in consolidated fields. Thus, both land abandonment and intensification appear to asymmetrically decrease habitats of rarer species. In light of our findings, we also discuss biodiversity conservation in agricultural landscapes with changing land use. © 2009 Elsevier B.V. All rights reserved.
Takagi S.,Museum of Nature and Human Activities |
Takagi S.,University of Tokyo |
Miyashita T.,University of Tokyo
Journal of Animal Ecology | Year: 2015
Despite recent attempts to quantify the relative strength of density- and trait-mediated indirect effects, rarely has the issue been properly addressed at the population level. Most research is based on short-term small-scale experiments in which behavioural and/or physiological responses prevail. Here, we estimated the time-scales during which density- and trait-mediated effects manifest, as well as the strength of these effects, using an interaction chain with three organisms (deer-plant-butterfly). A hierarchical Bayesian model was performed by using a long-term data set of deer density in the Boso Peninsula, central Japan (where local densities differ spatially and temporally) as well as densities of the swallowtail butterfly Byasa alcinous and its host plant Aristolochia kaempferi. The time-scale effect of deer on plant quantity and quality was estimated according to the degree of carry-over effects. The negative influence on leaf density showed a temporal saturation pattern over the long term, while the positive influence on leaf quality due to resprouting of leaves after deer browsing showed no clear temporal trend. The net indirect effect changed from positive to negative with time, with the negative density-mediated effect becoming prominent in the long term. Our novel approach is widely applicable in assessing the dynamic impacts of wildlife if the spatio-temporal variability of expansion and/or invasion history is known. © 2015 British Ecological Society.
Tsuji M.,Kobe University |
Ushimaru A.,Kobe University |
Osawa T.,Kobe University |
Mitsuhashi H.,Museum of Nature and Human Activities
Landscape and Urban Planning | Year: 2011
Major drivers of amphibian declines via urbanization include land-use changes that cause loss, fragmentation, splits, and degradation of habitat. The effects of these changes in habitat conditions on the persistence of populations are expected to differ among species depending on their dispersal habits: species with strong site fidelity would likely be more affected by habitat loss and degradation, whereas species with highly dispersive habits would be more threatened by habitat fragmentation and split (the dispersal-dependent-decline hypothesis). To test this hypothesis, we examined the distribution patterns of two paddy-associated frog species (Pelophylax nigromaculatus and Hyla japonica) with different dispersal habits along a rural-urban gradient of the Osaka-Kobe metropolitan area, Japan. Our results partially support the dispersal-dependent-decline hypothesis in that the species with strong site fidelity, i.e., P. nigromaculatus, was threatened by habitat-area (agricultural field) decline and habitat-quality degradation (prevalence of concrete levees) rather than by habitat fragmentation. To the best of our knowledge, our study is the first report that suggests paddy-associated amphibian declines via urbanization in the Asian region. However, the second half of the hypothesis, i.e., that the dispersive species (H. japonica) would be more strongly affected by habitat fragmentation via roads and habitat split via declines in surrounding forests was not supported. The lack of support for this portion of the hypothesis may be due to the high adaptability of H. japonica to artificial landscapes. We discuss the value of the dispersal-dependent-decline hypothesis for conservation planning in agricultural lands of urban areas. © 2011 Elsevier B.V.
Kobayashi F.,Museum of Nature and Human Activities
Paleontological Research | Year: 2016
Specimens of Parafusulina japonica (Gümbel), middle Permian (late Wordian) Fusulinoidea from a small, exotic limestone block within the Middle Jurassic Kamiyozawa Formation exposed at Tamanouchi, west Tokyo, Japan, show considerable morphologic variation and include microspheric forms. The megalospheric specimens vary greatly in the shape and size of their tests, expansion of their tests, and in the shape and size of their proloculi. Two microspheric specimens are about twice the size of the megalospheric specimens and show early whorls to be schubertellid-like. The presence or absence of an initial one or two endothyroid whorl is not established. The shape of septal folds seems distinctive as they have slightly wider, flattened or slightly rounded dome-shaped tops both in megalospheric and microspheric forms. Cuniculi are absent in early whorls and quite poorly developed in later whorls where they are low inconspicuous features, suggesting a relatively early evolutionary stage in the Parafusulina lineage. The features of the megalospheric specimens have led some authors to place this species in the genus Parafusulina (Skinnerella) or even as a separate genus, Skinnerella. However, the microspheric specimens are much more typical of the genus Parafusulina (Parafusulina), and so P. japonica will be placed in the unsubdivided genus Parafusulina. © by the Palaeontological Society of Japan.
News Article | October 23, 2015
Researchers from the Institute of Natural and Environmental Sciences at the University of Hyogo revealed that, for the time time in the world, they have discovered giant squid babies off the coasts of Japan. Giant squid are rarely seen alive in their natural habitat, and their mystery and size make them ideal subjects for monster movies. These sea creatures can grow over 33 feet (10 meters), making them the world's largest invertebrate. While we won't go so far as to say these babies are cute, the discovery will help researchers understand more about what the species is like at a young age. Adult giant squid are known to be loners, but a fisherman caught three giant squid babies off the coast of Shimane prefecture back in 2013. Unfortunately, two of the babies were found dead, but the fisherman also caught a live one and consulted with a local aquarium. Staff from the aquarium sent a picture of the strange-looking sea creature to marine biologist and cephalopod expert at the Institute of Natural and Environmental Sciences Toshifumi Wada, who requested the specimens be frozen and shipped to his lab. Wada was then able to confirm the specimens were in fact the first giant squid babies to ever be recorded, detailing his findings in a paper published in the journal of Marine Biodiversity Records this week. The giant squid babies, or more properly known as Architeuthis dux, varied in size from 14 to 33 centimeters (5.5 to 13 inches) and weighed in at less than a pound. Since giant squid babies are around the same size as regular adult squid, Wada was able to identify them as young Architeuthis dux since they have longer arms and a different arrangement of their sucker pads located on their tentacles than the older squid. Wada was then able to confirm his finding by genetic analysis. The young squid are planned to be displayed in the Museum of Nature and Human Activities in Hyogo, Japan.