No abstract

Decades of research have revealed the crucial roles of cross-system energy flows (spatial subsidies) in mediating trophic interactions in recipient systems. Food web theory predicts that the responses of subsidized consumers are a key to understanding the net impacts of spatial subsidies on in situ prey/resources of recipient systems. However, less is known about the factors triggering the cascading biotic interactions across coupled ecosystems. Here, we quantify how riverine productivity (donor system) mediates terrestrial food web interactions through spatial subsidies to simplified gravel bar communities. Our comparative study in Japan indicated that higher algal biomass in aquatic systems led to increased supplies of emerging aquatic insects, which were associated with greater densities of terrestrial consumers (Carabid beetles) and enhanced consumption rates of supplemental in situ prey on gravel bars. Our results highlight the potential of donor productivity to drive cascading biotic interactions across coupled ecosystems. Since cross-system energy flows should originate, at least in part, from primary producers of donor systems, our fundamental finding may form the basis of future studies exploring the driving factors of cross-system trophic interactions.

Farmland expansion is a growing threat to aquatic biodiversity. Identifying conservation priority areas in agricultural landscapes is a key issue in freshwater ecology and information on the spatial variability of aquatic biodiversity is vital for prioritization. This study examined patterns of farmland fish assemblages across various water‐body types in northern Japan to develop an effective management plan for freshwater fishes. Water bodies were classified into five types: small lowland streams, small upland streams, large rivers, man‐made ditches, and wetland ponds, and native fishes were collected from each type. The contribution of fish diversity between water‐body types (β2) to the regional fish diversity (γ) was investigated through additive diversity partitioning. Within each water‐body type, the contributions of between‐site diversity (β1) and within‐site diversity (α1) were also examined. The assemblage composition, species richness, and rarity were compared among the water‐body types. The assemblage composition differed significantly among most of the water‐body types, which indicated that the landscape classification was appropriate for representing spatial variations in fish diversity. Additive diversity partitioning revealed that the contributions of β1 and β2 to γ fish diversity were relatively high at 38.2% and 37.3%, respectively, followed by a 24.5% contribution of α1 diversity. This finding demonstrates that the best strategy for conserving regional farmland fish diversity is to preferentially select areas containing various water‐body types as a conservation unit. Among the water‐body types, ditches and streams exhibited the higher contribution ratio for β1 diversity, whereas the contribution of β1 diversity was lower in wetland ponds. The differences in the contribution of β1 diversity might be attributed to human‐induced factors, such as habitat fragmentation or shrinking. These results emphasize that further studies are needed to clarify the factors influencing the β1 diversity of farmland fish to develop better management strategies for each water‐body type. Copyright © 2015 John Wiley & Sons, Ltd.

In the heavy snowy and cold cities, huge energy and cost have been spent for cleaning snow in urban area, especially in public area roads and pedestrian ways. It causes to the global warming, therefore cutting back on the emission of gases is required to the urban design in the snowy cities. Authors developed the block designs that reduce the snow accumulation on the public roads and pedestrian ways in downtown area Sapporo City, Hokkaido Japan. Four types of the block designs, individual developing type, unified height type, mountain shape type and close rounding type were compared how much accumulate snow in the public area with snow simulations using the wind tunnel. At the result, the block design with close rounding type should be most desirable design for reducing snow cleaning energy and emission CO2 gases in downtown area.

Regional cities in Japan are facing a decline in the downtown area owing to urban expansion and a decrease in the population. Promoting downtown living is indispensable for the realization of downtown revitalization. Since many coastal cities originally developed outward from a port, their downtown areas are located near the coast and are at high risk of tsunamis. The purpose of this research is to reveal the effectiveness of dealing with the above two issues in parallel by evaluating the Deae-ru Saiwai estate, a public housing relocation project in downtown Kushiro, Hokkaido, Japan that incorporates a tsunami evacuation facility with questionnaires and a GIS survey. Placing public housing in the downtown area shortens the distance to public facilities and improves the convenience of the surrounding environment for many residents. Installing the tsunami evacuation facility improves the feeling of reassurance of residents who would feel anxiety about immigration with regards to tsunamis. This research has clarified the synergistic effect of dealing with the daily and emergency issues in parallel for promoting downtown living. Planning downtown revitalization and disaster prevention concurrently, which has been separated so far, is a fundamental planning approach for urban revitalization in regional coastal cities.