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In Japan, rice paddies have acted as substitute habitats for pond-breeding frogs. However, frog populations are declining due to the loss of habitat and environmental changes in rice paddy areas. Frogs need both aquatic and terrestrial habitats to complete their life history; in rice paddy areas, levees that surround rice paddies provide terrestrial habitats for basking, foraging, and shelter from predators. Studying microhabitat use at levees is important to elucidating the ecological roles of levees and to properly managing them to support frog populations. In this study, we conducted surveys in lowland modernized rice paddy areas in Shiga Prefecture in which a common species, Hyla japonica, and an endangered species, Pelophylax porosa brevipoda, were found. We captured frogs at levees and recorded environmental factors related to levee vegetation, rice paddy conditions, and weather. We constructed generalized linear mixed models to examine the effects of environmental factors on juvenile and adult H. japonica and on small and large juveniles, females, and males of P p. brevipoda. Our results showed distinct microhabitat uses at levees in different species, sexes, and body sizes. In general, abundance was high at levees with vegetation that provided shelter. The water depth in rice paddies negatively influenced juvenile H. japonica and large juvenile and small female P p. brevipoda, and positively influenced small male P p. brevipoda. The maintenance of a mosaic structure of levees was important not only to support frog popula- tions but also to maintain frog diversity in the area. [ABSTRACT FROM AUTHOR]

Stream macroinvertebrate assemblages are expected to be affected by the abundance and constitution of litter from surrounding forests. We compared forest floor cover, overland flow, stream environment, and stream macroinvertebrate assemblages between the catchments of a Japanese cedar plantation (CP) and a primary deciduous forest (DF). Both systems experience excessive deer browsing. Understory vegetation cover was higher in the DF than in the CP in summer, although cover was low (<20 %), possibly because of excessive deer browsing. Litter cover was much higher in the CP than in the DF in summer as a result of the long abscission period, slow breakdown, and low rate of dispersal of Japanese cedar litter compared to deciduous litter. Monthly overland flow was always lower in the CP than in the DF, and substrate size was smaller in the DF stream. In the CP, cedar litter accumulated in the stream, probably because of its low breakdown rate and morphology, and abundant shredder taxa characterized the macroinvertebrate assemblage. In contrast, abundant burrower taxa characterized the macroinvertebrate assemblage in the DF stream. These results imply that Japanese cedar litter functions in structuring the macroinvertebrate assemblage by supplying persistent food resources for detritivores, and by buffering fine sedimentation via overland flow under excessive deer browsing.Stream macroinvertebrate assemblages are expected to be affected by the abundance and constitution of litter from surrounding forests. We compared forest floor cover, overland flow, stream environment, and stream macroinvertebrate assemblages between the catchments of a Japanese cedar plantation (CP) and a primary deciduous forest (DF). Both systems experience excessive deer browsing. Understory vegetation cover was higher in the DF than in the CP in summer, although cover was low (<20 %), possibly because of excessive deer browsing. Litter cover was much higher in the CP than in the DF in summer as a result of the long abscission period, slow breakdown, and low rate of dispersal of Japanese cedar litter compared to deciduous litter. Monthly overland flow was always lower in the CP than in the DF, and substrate size was smaller in the DF stream. In the CP, cedar litter accumulated in the stream, probably because of its low breakdown rate and morphology, and abundant shredder taxa characterized the macroinvertebrate assemblage. In contrast, abundant burrower taxa characterized the macroinvertebrate assemblage in the DF stream. These results imply that Japanese cedar litter functions in structuring the macroinvertebrate assemblage by supplying persistent food resources for detritivores, and by buffering fine sedimentation via overland flow under excessive deer browsing.

AbstractStream macroinvertebrate assemblages are expected to be affected by the abundance and constitution of litter from surrounding forests. We compared forest floor cover, overland flow, stream environment, and stream macroinvertebrate assemblages between the catchments of a Japanese cedar plantation (CP) and a primary deciduous forest (DF). Both systems experience excessive deer browsing. Understory vegetation cover was higher in the DF than in the CP in summer, although cover was low (<20 %), possibly because of excessive deer browsing. Litter cover was much higher in the CP than in the DF in summer as a result of the long abscission period, slow breakdown, and low rate of dispersal of Japanese cedar litter compared to deciduous litter. Monthly overland flow was always lower in the CP than in the DF, and substrate size was smaller in the DF stream. In the CP, cedar litter accumulated in the stream, probably because of its low breakdown rate and morphology, and abundant shredder taxa characterized the macroinvertebrate assemblage. In contrast, abundant burrower taxa characterized the macroinvertebrate assemblage in the DF stream. These results imply that Japanese cedar litter functions in structuring the macroinvertebrate assemblage by supplying persistent food resources for detritivores, and by buffering fine sedimentation via overland flow under excessive deer browsing.

In Japan, rice paddies play an important role as a substitute habitat for wetland species, and support rich indigenous ecosystems. However, since the 1950s, agricultural modernization has altered the rice paddy environment, and many previously common species are now endangered. It is urgently necessary to evaluate rice paddies as habitats for conservation. Among the species living in rice paddies, frogs are representative and are good indicator species, so we focused on frog species and analyzed the influence of environmental factors on their habitat use. We found four frog species and one subspecies (Hyla japonica, Pelophylax nigromaculatus, Glandirana rugosa, Lithobates catesbeianus, and Pelophylax porosa brevipoda) at our study sites in Shiga prefecture. For all but L. catesbeianus, we analyzed the influence of environmental factors related to rice paddy structure, water management and availability, agrochemical use, connectivity, and land use on breeding and non-breeding habitat use. We constructed generalized additive mixed models with survey date as the smooth term and applied Akaike's information criterion to choose the bestranked model. Because life histories and biological characteristics vary among species, the factors affecting habitat use by frogs are also expected to differ by species. We found that both breeding and non-breeding habitat uses of each studied species were influenced by different combinations of environmental factors and that in most cases, habitat use showed seasonality. For frog conservation in rice paddies, we need to choose favorable rice paddy in relation to surrounding land use and apply suitable management for target species. [ABSTRACT FROM AUTHOR]

Abstract: The harvest mouse Micromys minutus (Pallas 1771), a small rodent, builds its nests on tall grasses such as Amur silvergrass Miscanthus sacchariflorus (Maxim.) Benth. This mouse species is endangered by grassland habitat loss worldwide. Although embankments are one of the mouse’s nest sites in Japan, these habitats are not stable because of regular mowing. To investigate ways of increasing the habitat suitability of embankments, research was carried out over a 2-year period in western Japan on an embankment where Amur silvergrass was dominant. Two to three divisions of the embankment were mowed at intervals in spring and autumn, and seasonal changes in nesting and vegetation were examined. Nest sites were evaluated using Manly’s index. In each year, the nesting period was extended and more nests were built compared to past years when phased mowing was not performed. The density of nests in each division increased in order of mowing in spring, but was low in autumn. Amur silvergrass was the preferred nesting plant and other perennial grasses were avoided. Annual grasses were preferred over Amur silvergrass in 2005. Nesting restarted when Amur silvergrass recovered to heights of >100 cm in all divisions, regardless of the mowing month. Each year, 120–160-cm-tall Amur silvergrass was preferred, while plants <80 cm high were avoided. Phased mowing, which allows annual grasses and Amur silvergrass sufficient time to recover, is clearly an effective method of maintaining stable nesting habitat for the harvest mouse on an embankment.

Landscape evaluation is important in the conservation of biodiversity and sustainable development. The objective of this paper is to review and explore methods for evaluation of landscapes for ecosystem planning. Ecosystem planning is the process of land use decision-making that considers organisms and processes that characterize the ecosystem as a whole. Risk assessments, precautionary principles, adaptive management and scenario approaches are adopted to cope with the uncertainty of nature, which is an obstacle in ecosystem planning. Special attention is needed in the analysis of status and troubleshooting in the planning scheme, which is a selection of the appropriate approach and model to find problems in the present situation. There are two approaches to set targets in ecosystem planning, the species approach and the ecosystem approach. The species approach aims to protect particular species, and the ecosystem approach aims to protect total ecosystems including the species. In Europe, ecotope or biotope mapping has been developed in ecosystem planning. An ecotope is often identified by vegetation that represents a group of wildlife, but many species require combinations of different ecotopes. Landscapes have come to be recognized as a unit for ecosystem planning. Potential assessment is a method to estimate a potential of a local space or a landscape to realize an ecosystem or species’ habitat, and this method has been used in HEP and GAP analysis in the USA and Ecological Networks in Europe. Some examples of ecosystem planning of national and regional scales in Japan are introduced.Landscape evaluation is important in the conservation of biodiversity and sustainable development. The objective of this paper is to review and explore methods for evaluation of landscapes for ecosystem planning. Ecosystem planning is the process of land use decision-making that considers organisms and processes that characterize the ecosystem as a whole. Risk assessments, precautionary principles, adaptive management and scenario approaches are adopted to cope with the uncertainty of nature, which is an obstacle in ecosystem planning. Special attention is needed in the analysis of status and troubleshooting in the planning scheme, which is a selection of the appropriate approach and model to find problems in the present situation. There are two approaches to set targets in ecosystem planning, the species approach and the ecosystem approach. The species approach aims to protect particular species, and the ecosystem approach aims to protect total ecosystems including the species. In Europe, ecotope or biotope mapping has been developed in ecosystem planning. An ecotope is often identified by vegetation that represents a group of wildlife, but many species require combinations of different ecotopes. Landscapes have come to be recognized as a unit for ecosystem planning. Potential assessment is a method to estimate a potential of a local space or a landscape to realize an ecosystem or species’ habitat, and this method has been used in HEP and GAP analysis in the USA and Ecological Networks in Europe. Some examples of ecosystem planning of national and regional scales in Japan are introduced.

Abstract Sustainability of the wetland ecosystems in the Aral Sea region depends on the ecological dynamic processes resulting from shifting mosaic patterns along the ecotone. The “Pelican Scenario”, a natural dynamism-oriented nature restoration plan for the Aral Sea crisis, should be considered not only for achieving sustainable land use, but also for the conservation of Pelecanus crispus, a vulnerable species.

We 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.

Abstract: We 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.