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Yokohama-shi, Japan

Tsuyuzaki S.,Hokkaido University | Matsuda M.,Hokkaido University | Matsuda M.,IDEA Consultants Inc. | Akasaka M.,Hokkaido University | Akasaka M.,Japan National Institute of Environmental Studies
Climate Research | Year: 2012

To detect the effects of a deciduous shrub Salix reinii on microclimate along a gradient of elevation during the snow-free period, we measured ground surface temperature and surface photosynthetically active radiation (PAR) for bare ground and S. reinii patches (henceforth 'patches'). Measurements were made at low (560 m above sea level), middle (665 m), and high (755 m) elevations on the Mount Koma volcano in northern Japan. Soil water content was also measured for bare ground and under S. reinii patches at the middle elevation, and wind speed was measured on bare ground at all 3 elevations. The forest canopy, dominated by Larix kaempferi, was more developed at lower elevations, and wind speeds there were lower. The PAR value in patches decreased with increasing foliage, which also reduced temperature fluctuations at all 3 elevations. The water content remained higher in patches than on bare ground. These observations show that shrub cover markedly reduces temperature fluctuation and soil desiccation by intercepting solar radiation. Differences in microclimate between the 3 elevations were less in the shrub patches, showing that the patches weakened the effects of elevation and canopy on microclimate at each of the elevations surveyed. © Inter-Research 2012. Source

Yamada T.,Yamada Science and Art Corporation | Koike K.,IDEA Consultants Inc.
Journal of Wind Engineering and Industrial Aerodynamics | Year: 2011

Considerable interest exists in joining the capabilities of mesoscale meteorological models (MMM) with those of computational wind engineering (CWE) models to produce realistic simulations, which address emerging issues in wind engineering and environmental applications. The model equations are similar for MMM and CWE, but there are significant differences in the objectives and approaches. Complete synthesis of these models is still premature and computational burdens are enormous. Appropriate procedures for joining these models have not been established yet and measurement data required for verification is limited.For convenience in presentations and discussions, coupling methods are divided into four groups: (1) coupling MMM and CWE models for up-scaling or downscaling, (2) up-scaling a CWE model to include the mesoscale meteorological influences, (3) downscaling an MMM to include the CWE capabilities, and (4) a combination of the above three approaches. Mochida et al. (this issue) focuses on up-scaling CWE from an engineering point of view and the present paper focuses on downscaling MMM from a meteorological point of view. Topics addressed here are (1) to understand the differences in the purposes and approaches of MMM and CWE models and (2) to identify issues and explore ways of coupling MMM and CWE modeling capabilities. © 2011 Elsevier Ltd. Source

Marionina biwaensis sp. nov. is described from Lake Biwa. This new species differs from all other Marionina species: lacking lateral chaetae completely and ventral chaetae in II, segment number 38-43, origin of dorsal blood vessel XV or XVI, spermathecal ampullae with irregular protuberances and chaetal distribution 1 per postclitellar bundles. In addition, the descriptions of M. coatesae, M. nevisensis, and M. riparia are augmented and recorded here for the first time in Japan. © TÜBİTAK. Source

Yamanishi Y.,Nara Womens University | Yamanishi Y.,IDEA Consultants Inc. | Yoshida K.,Japan National Agricultural Research Center | Fujimori N.,Toyohashi University of Technology | Yusa Y.,Nara Womens University
Biological Invasions | Year: 2012

Species richness in local communities has been considered an important factor determining the success of invasion by exotic species (the biotic resistance hypothesis). However, the detailed mechanisms, especially the role of predator communities, are not well understood. We studied biotic resistance to an invasive freshwater snail, Pomacea canaliculata, at 31 sites in an urban river basin (the Yamatogawa) in western Japan. First, we studied the relationship between the richness of local animal species and the abundance of P. canaliculata, demonstrating a negative relationship, which suggests that the intensity of biotic resistance regulates local snail populations. This pattern was due to the richness of native predator communities rather than that of introduced species or non-predators (mainly competitors of the apple snail). Local snail abundance was also affected by immigration of snails from nearby rice fields (i. e. propagule pressure), where few predators occur. Second, we assessed short-term predation pressure on the snail by means of a tethering experiment. Predation pressure was positively correlated with the number of individual predators and negatively correlated with snail abundance. The introduced crayfish Procambarus clarkii was responsible for the variance in predation pressure. These results indicate that the predator community, composed of both native and introduced species, is responsible for resistance to a novel invader even in a polluted urban river. © 2011 Springer Science+Business Media B.V. Source

Three species of semi-aquatic freshwater Enchytraeidae of the genera Mesenchytraeus Eisen, 1878, Chamaedrilus Friend, 1913 and Globulidrilus Christensen & Dózsa-Farkas, 2012 are described from stream, wet soil or snow habitats in the Ozegahara Mire, an extensive high moor in heavy snowfall area in central Japan. Among Mesenchytraeus speies, Mes-enchytraeus nivalis sp. nov. is distinguished by not having enlarged chaetae and spermathecal diverticula, vas deferens with atrial glands 3 or 4 in number and club-shaped, spermathecal ental duct short, with sperm bundles in the sperm sack. Chamaedrilus ozensis sp. nov. closely resembles C. floridae, but the length of the sperm funnel and character of the coelo-mocytes are different. Globulidrilus helgei Christensen & Dózsa-Farkas, 2012 is recorded for the first time from Japan. Copyright © 2015 Magnolia Press. Source

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