Mountains Of Central Japan Research Articles

Comparing information derived on food habits of a terrestrial carnivore between animal-borne video systems and fecal analyses methods.

In recent years, animal-borne video cameras have been used to identify the food habits of many species. However, the usefulness and difficulties of identifying food habits from animal-borne video cameras have not been sufficiently discussed in terrestrial mammals, especially large omnivores. The aim of this study is to compare the video analysis of foraging behavior by Asian black bears (Ursus thibetanus) acquired by camera collars with estimates from fecal analysis. We attached GPS collars equipped with video cameras to four adult Asian black bears in the Okutama mountains in central Japan from May to July 2018 and analyzed video clips for foraging behavior. Simultaneously, we collected bear feces in the same area to determine food habits. We found that using video analyses was advantageous to recognize foods, such as leaves or mammals, that were physically crushed or destroyed while bears chewed and digested foods, which are difficult to identify to species using fecal analyses. On the other hand, we found that camera collars are less likely to record food items that are infrequently or quickly ingested. Additionally, food items with a low frequency of occurrence and short foraging time per feeding were less likely to be detected when we increased the time between recorded clips. As one of the first applications of the video analysis method for bears, our study shows that video analysis can be an important method for revealing individual differences in diet. Although video analysis may have limitations for understanding the general foraging behavior of Asian black bears at the present stage, the accuracy of food habit data from camera collars can be improved by using it in combination with established techniques such as microscale behavior analyses.

Altitude shape genetic and phenotypic variations in growth curve parameters of Larix kaempferi

To study the effects of geoclimatic variables of provenances on growth phenotypes and selected plus provenances, over 3000 trees of 22-year-old Larix kaempferi were evaluated from trials established in two climate zones for provenance selection and to explore the influence of climate variables on provenance performance. The material was replicated plantings of 84 open pollinated families from six provenances distributed in the mountains of central Japan. Provenance variation was observed in most age groups and the heritability of growth traits showed large differences. The phenotypic maximum value of height and diameter were significantly positive with altitude, and mean annual precipitation being important factors. Diameter at breast height growth was significantly negative with altitude and spring rainfall. The Ina provenance of relatively high altitudes, was well adapted to a variety of climates. Altitude might be the driving force for phenotypic and genetic variations and local adaptation.

Visitation frequencies of bumblebees and swallowtail butterflies to flowers and the nectar sugar concentration of <i>Rhododendron kaempferi</i> and <i>R. japonicum</i> in mountains of central Japan

Relationships between flower visitor composition and floral traits help us to understand floral evolution. Swallowtail butterflies have been assumed to be the main pollinators of Rhododendron kaempferi and R. japonicum based on their floral shapes, and R. kaempferi was reported to be pollinated by butterflies in southern Japan. In the mountains of central and northern Japan, however, bumblebees are abundant and candidate pollinators of Rhododendron. We found that visitation frequencies of bumblebees were higher than those of swallowtail butterflies to both of the Rhododendron species at three study sites in the mountains of central Japan. R. japonicum pollen adhered to the bodies of both floral visitors. Further, the nectar sugar concentration of R. kaempferi was in the preference range of bumblebees, whereas that of R. japonicum was suited to both bumblebees and butterflies. Taken together, these findings support the hypothesis that bumblebees are potentially also important pollinators of R. kaempferi and R. japonicum in mountains of central Japan, where they are more abundant than swallowtail butterflies.

Two new species of the genus Trichoribates (Acari: Oribatida: Ceratozetidae) from Central Japan

The present paper deals with two species of oribatid mites of the genus Trichoribates Berlese, 1910 from the subalpine zone of high mountains in Central Japan. Trichoribates aokii n. sp. and Trichoribates hirauchiae n. sp. are proposed on the basis of adults. The first species is characterized by narrow lamellar cusps and translamella, and very closely situated notogastral setae h2 and h3. The second species is readily distinguishable from other closely related species by the specific structure of porose areas A1 and A2, the larger body size, the longer interlamellar and rostral setae, and anteriorly converging lamellae. A key to the Japanese species of Trichoribatesis provided along with data on their geographical distribution and habitat ecology.

Soil microbial response to experimental warming in cool temperate semi‐natural grassland in Japan

AbstractTo assess soil microbial response to global warming in cool temperate semi‐natural grassland, we conducted an in situ warming experiment in grassland located in the mountains of central Japan. Five pairs of plots (control and warmed) of Zoysia japonica were established. For each pair of plots, one was warmed by ca. 2 °C using infrared heaters during the growing seasons of 2009–2011. Above‐ground biomass of Z.japonica was estimated using the modified point‐frame method. Soil organic matter contents, soil total carbon and nitrogen contents, as well as inorganic nitrogen (ammonium and nitrate) contents were determined from soil samples. Total phospholipid fatty acid (PLFA) contents and PLFA compositions were determined and used as indices for total microbial biomass and community structure, respectively. Analyses showed that the warming increased the above‐ground biomass of Z. japonica significantly. Soil organic matter and soil total nitrogen contents were significantly decreased, while soil ammonium content was significantly increased in the warmed plots. Soil microbial biomass (especially fungal biomass) was lower in the warmed plots, probably reflecting higher temperature, lower soil water content, and/or depletion in available nutrients. The significant decrease in fungal biomass, in combination with our PLFA composition data, suggests that the soil microbial community structure shifted from a fungal‐dominated to a bacteria‐dominated one, causing changes in community‐level physiological activity.

Species richness of seed plants and ferns along a temperate elevational gradient in central Japan

We evaluated richness patterns of all vascular plants in central Japan with respect to spatial and climatic factors. This evaluation was performed by analysing a database that contained information on 150,806 herbarium specimens from this region. We analysed the area-corrected and rarefied species richness of all vascular plants, seed plants and ferns at 100-m elevational bands. The area-corrected species richness showed an asymmetric hump-shaped pattern for total and seed plants with a plateau in a higher elevation, whereas fern species richness showed a decreasing pattern. The rarefied species richness showed a low-plateau pattern in all cases because of the low threshold; however, species richness by rarefaction of specimens down to a higher threshold supported the area-corrected pattern. Thus, we concluded that total and seed plant richness showed a hump-shaped pattern, and that fern richness showed a decreasing pattern. Area, temperature and precipitation were significantly correlated with species richness, and climatic factors explained more variation in species richness of ferns compared with that of seed plants. When the species were divided based on range size, climatic factors explained more variation in small-ranged species richness than spatial factors, whereas spatial factors did so in large-ranged species richness. In addition, small-ranged species richness of seed plants showed a bimodal pattern with peaks at low elevation and high elevation probably because the mountains in central Japan play a role as refugia for Japanese alpine plants during climatic oscillations, or an artefact.

Colliding fragment islands transport independent lineages of endemic rock-crawlers (Grylloblattodea: Grylloblattidae) in the Japanese archipelago

Fragment islands, viewed from the paradigm of island biogeographic theory, depend on continual immigration from continental sources to maintain levels of species diversity, or otherwise undergo a period of relaxation where species diversity declines to a lower equilibrium. Japan is a recently derived fragment island with a rich endemic flora and fauna. These endemic species have been described as paleoendemics, and conversely as recently derived Pleistocene colonists. Geological events in the Miocene period, notably the fragmentation and collision of islands, and the subsequent uplift of mountains in central Japan, provided opportunities for genetic isolation. More recently, cyclical climatic change during the Pliocene and Pleistocene periods led to intermittent land bridge connections to continental Asia. Here we investigate the pattern and timing of diversification in a diverse endemic lineage in order to test whether ongoing migration has sustained species diversity, whether there is evidence of relaxation, and how geological and climatic events are associated with lineage diversification. Using multi-locus genetic data, we test these hypotheses in a poorly dispersing, cold-adapted terrestrial insect lineage (Grylloblattodea: Grylloblattidae) sampled from Japan, Korea, and Russia. In phylogenetic analyses of concatenated data and a species tree approach, we find evidence of three deeply divergent lineages of rock-crawlers in Japan consistent with the pattern of island fragmentation from continental Asia. Tests of lineage diversification rates suggest that relaxation has not occurred and instead endemism has increased in the Japanese Grylloblattidae following mountain-building events in the Miocene. Although the importance of climate change in generating species diversity is a commonly held paradigm in Japanese biogeography, our analyses, including analyses of demographic change and phylogeographic range shifts in putative species, suggests that Pleistocene climatic change has had a limited effect on the diversification of rock-crawlers.

Comparison of wood-inhabiting myxomycetes in subalpine and montane coniferous forests in the Yatsugatake Mountains of Central Japan

To demonstrate altitudinal gradients (and resulting temperatures) that affect myxomycete biodiversity and species composition, we statistically compared myxomycete assemblages between a subalpine coniferous forest and a montane pine forest within the region of the Yatsugatake Mountains, Nagano Prefecture, Central Japan. In summer and autumn field surveys during 2003-2010, 53 myxomycete taxa (with varieties treated as species) were observed from 639 records of fruiting bodies in the subalpine forest and 32 taxa were detected from 613 records in the montane forest. There were 20 species in common between the assemblages and the percentage similarity index was 0.400. Myxomycete biodiversity was higher in the subalpine than in the montane forest. Nine myxomycete species were statistically frequent occurrences in the subalpine forest and appeared in autumn: Lamproderma columbinum, Cribraria macrocarpa, Trichia botrytis, Physarum newtonii, Diderma ochraceum, Enteridium splendens, Elaeomyxa cerifera, Trichia verrucosa, and Colloderma oculatum. Five species were restricted to appear in the subalpine forest: Cribraria purpurea, Cribraria rufa, Cribraria ferruginea, Cribraria piriformis, and Lepidoderma tigrinum. Dead wood in the subalpine forest provided a breeding habitat for specific myxomycetes that inhabit cold areas; that is those areas having geographical features of decreasing temperature and increasing elevation, such as the temperate area of Central Japan.

佐渡島と新潟県内陸の山岳におけるオゾン濃度の垂直変化と季節変動

From April to November in 2008, we observed altitudinal and seasonal changes in the monthly mean ozone concentrations using passive samplers at two mountains in Niigata Prefecture: Mt. Bunagahira on Sado Island and Mt. Hakkai, located on the mainland. The mean ozone concentrations at both mountains were the highest in spring (May), and decreased in summer. The ozone concentrations at Mt. Bunagahira increased in autumn again. Such a seasonal change in the mean ozone concentrations was the same pattern observed at other mountains in central Japan as well as plains in western part of Japan. The monthly mean ozone concentrations increased with the altitude at Mt. Hakkai. Such an altitudinal change in ozone concentrations was the similar pattern observed at other mountains in central Japan. In contrast, the mean ozone concentrations of each month showed similar values at all altitudes on each slope side of Mt. Bunagahira showing a different tendency with other mountains observed in Japan. This phenomenon might be resulted from few local origins of air pollutants around Mt. Bunagahira that generate or decompose ozone. The mean ozone concentrations on the slope of Mt. Bunagahira facing northwest were higher than those facing southeast in every month. This phenomenon might suggest that the mean ozone concentrations transported from the direction of East Asian continent were higher than those of the mainland in Niigata Prefecture.

Is representative elementary area defined by a simple mixing of variable small streams in headwater catchments?

AbstractThe spatial variability of hydrology may decrease with an increase in catchment area as a result of mixing of numerous small‐scale hydrological conditions. At some point, it is possible that a threshold area, the representative elementary area (REA), can be identified beyond which an average hydrologic response occurs. This hypothesis has been tested mainly via numerical simulations, with only a few field studies involving simple mixing. We tested this premise quantitatively using dissolved silica (SiO2) concentrations at 96 locations that included zero‐order hollow discharges through sixth‐order streams, collected under low‐flow conditions within the 4·27‐km2 Fudoji catchment. The catchment possesses a simple topography consisting almost solely of hillslopes and stream channels, uniform bedrock geology, soil type and land use in the Tanakami Mountains in central Japan. Dissolved SiO2 provides a useful tracer in hydrological studies insofar as it is responsive to flowpath depth on hillslopes of uniform geology. Our results demonstrate that even in a catchment with an almost homogeneous geology and simple topography, dissolved SiO2 concentrations in zero‐order hollow discharges largely varied in space and they became similar among sampling locations with area of more than 10−1–100 km2. Relationships between stream order and standard deviation of SiO2 concentration closely matched the theoretical predictions from simple mixing of random fields. That is, our field data supported the existence of the REA and showed that the REA was produced by the simple mixing of numerous small‐scale hydrological conditions. The study emphasizes the need to consider both the heterogeneous nature of small‐scale hydrology and the landscape structure when assessing the characteristics of catchment runoff. Copyright © 2010 John Wiley & Sons, Ltd.

The phylogeographic structure of Japanese coniferous species as revealed by genetic markers

AbstractThe phylogeography of Japanese conifers studied using polymorphic allozyme and organelle (chloroplast and mitochondrial) DNA markers is reviewed. Three Abies species showed a clear geographical cline based on mtDNA polymorphisms. Allozyme markers revealed a clear genetic cline in A. mariesii, with no mtDNA polymorphism. Refugia of these species during the last glaciation were probably located along the southwestern Pacific side of Japan. Based on allozyme analysis, Pinus pumila may have migrated from Siberia southward from Hokkaido to higher mountains in central Japan. Mitochondrial DNA polymorphisms clearly differentiated the pentaphylla and parviflora varieties of Pinus parviflora and suggest that refugia of the latter species were located south of the central mountains of Chubu district during the last glaciation. Current populations in the Chubu highlands, Tohoku, and Hokkaido presumably became established by colonization from these refugia. Phylogeographic analysis of Cryptomeria japonica using allozymes and DNA markers did not reveal distinct patterns. However, microsatellite analysis revealed highest allelic diversity in putative refugia of the last glaciation. Allozyme analysis of Chamaecyparis obtusa revealed a clear cline. Recently, substantial numbers of loci based on expressed sequence tags for population and genome mapping were developed. Cryptomeria japonica and Chamaecyparis obtusa belong to different families, but molecular phylogeny based on chloroplast sequence data revealed that they are closely related and that sequence tag site markers of C. japonica are highly applicable to C. obtusa. Using such markers, researchers have attempted to clarify the genetic structure of the two species. This paper also discusses the most successful approaches (to date) for elucidating the genetic structure of the above‐mentioned species and other phylogeographic issues related to Japanese conifers.

広域の大気状態が中部日本山岳地域の夏季の夜間冷却に及ぼす影響

広域の大気状態が中部日本山岳地域の夏季の夜間冷却に及ぼす影響

Evolution mechanisms of an earthquake swarm under the Hida Mountains, central Japan, in 1998

An earthquake swarm occurred under the Hida Mountains in central Japan in 1998. The focal area, which expanded from south to north, was distributed above the low‐velocity and high‐attenuation zone, which lies under the main range. During the swarm, there was a migration of focal areas with time delays. In this paper, we investigate the spatiotemporal distribution of earthquakes in the swarm and discuss the phenomenon that must have controlled the seismicity. Understanding the complicated spatial pattern of seismicity, we investigate the dependency of the occurrence of earthquakes on the static stress changes caused by preceding earthquakes. Our findings show that, for each of 18 major earthquakes (magnitudes 4.0 or higher), the estimated distribution of the resulting Coulomb failure stress corresponds to the expansion of focal areas and the distribution of the seismically quiescent region. However, the detailed structure of seismicity cannot be explained only by the static stress changes. We discuss two additional factors which may control delayed fractures: flow of underground water for the seismicity around the southernmost focal cluster and stress corrosion process for the leaps of seismicities. The results of this study suggest that the 1998 Hida swarm was strongly affected by the disturbances of a static stress field that was created by the swarm itself, although the magnitudes of static stress change are small. The seismic activity was initiated by swarm‐type seismicity around the southernmost cluster and then expanded northward gradually due to the increase in static stress.

Spatial and temporal changes of vegetation cover in granite mountains in central Japan: a GIS‐based approach

AbstractDegraded hillslope areas are widespread in the Tanakami area located in Shiga Prefecture of central Japan as a result of more than 1300 years of human impact. Consequently, accelerated erosion rates and high storm runoffs have been major environmental problems there. To attempt to stabilize hillslopes and to reduce sediment and water discharges, extensive reforestation projects have been conducted since the 1870s. The vegetation recovery in the Tanakami area over a 51‐year period was assessed using a geographic information system‐based approach. The results showed that, in the areas where only hillside planting work was conducted, the percentage of bare slope area increased mainly due to the destruction of the vegetation cover on the forested slopes with gradients exceeding 30 degrees, and/or on southwest and northwest slopes. Moreover, the destruction of vegetation cover on steep slopes was seen to be most prevalent where hillside planting work was conducted without slope terracing. In contrast, in the area where both hillside planting and tending works were implemented, the bare slope area tended to decrease through the study period. Consequently, in 1988, there were only 1 per cent of bare slopes in the area where both hillside planting and tending works were implemented; in contrast the bare slope areas where only hillside planting work was conducted still occupied 12–17 per cent. These results imply that the reforestation practices that include hillside planting and tending works, or at least slope terracing, are necessary to prevent the destruction of the vegetation cover on steep southwest and northwest slopes. Copyright © 2002 John Wiley & Sons, Ltd.

A Morphometric Approach to Post-Glacial Channel Development in the Mountains of Central Japan

A Morphometric Approach to Post-Glacial Channel Development in the Mountains of Central Japan

Accretion complexes and related forearc basins in the Cretaceous of central Japan, with special reference to the continuity of accretion tectonism and associated metamorphism

The Sambagawa, Chichibu and Shimanto belts in the Kanto Mountains of central Japan have been shown to be formed by accretion and the rocks of these belts have undergone various amounts of deformation and metamorphism. The three belts were successively accreted from north to south during the Jurassic to Neogene and the ages of deformation and metamorphism young towards the south. The different grades of deformation and metamorphism depend mainly on the depth of accretion of each belt. Two thin Cretaceous sedimentary units, the Atokura Formation and the Sanchu Cretaceous System are found on or near the boundary of the belts in the Kanto Mountains. These Cretaceous sediments were deposited in the forearc basins developed along the boundary of the belts and were deformed (or partly metamorphosed) by the differential movement of each belt. The deposition, deformation and metamorphism of the geological units of the Kanto Mountains in central Japan occurred serially in an accretionary regime and can be explained by accretionary tectonics. The tectonic events took place almost continually from the Jurassic to the Palaeogene.

Accumulation Terraces of the Quaternary Ice Age in the Mountains of Central Japan

Accumulation Terraces of the Quaternary Ice Age in the Mountains of Central Japan