Urban biodiversity studies explore how urban nature contributes to ecosystem services and how ecological theories can be applied in human-dominated environments. Japan, one of the most urbanized ...countries in the world, has a long tradition of urban ecology and can thus provide useful information on urban biodiversity structure and functions. However, to date, there have been few reflections on past Japanese urban biodiversity studies, partly because the related topics are spread across various academic fields. In this study, we reviewed 173 urban biodiversity studies in Japan, and analyzed research trends to understand why and how the reviewed papers studied urban biodiversity, as well as the limitations in previous study trends. Our results showed that the number of studies has increased since 2000, and that the studies often considered conservation and ecosystem services as their research basis, while there were few evaluations on the value of specific species in the urban environment. The results also showed that the studies were often conducted in Japanese megacities, and that they were highly biased towards plant, insect, and avifauna studies in forest habitats. These findings imply that future studies should consider connecting urban biodiversity and ecosystem service evaluations to broader habitats across larger numbers of taxa.
Urban green spaces play an important role in maintaining urban biodiversity in the Tokyo Metropolis, Japan. Plant-dependent insect assemblages such as Cerambycidae, in particular, are likely ...influenced by the existence of green spaces in Tokyo's urbanised environments. This study is the first comprehensive inventory of the cerambycid fauna in the Komaba Campus of the University of Tokyo. A cerambycid assemblage composed of a total of 25 species was recorded within the Komaba Campus site and compared to cerambycid assemblages in nine other green spaces distributed throughout Tokyo. The results indicated that the species number in the campus was similar to that recoded in a similar-sized green space in coastal Tokyo. Fewer cerambycid species were, however, found at the campus site than in larger-sized green spaces within Tokyo. Moreover, species compositions in urbanised areas were markedly different from those in suburbanised parks, mountains and forests within Tokyo.
Background : All human land use (LU) affects the distribution of plant species; however, the impacts vary with the type/intensity of LU. For managing ecosystems, it is therefore essential to ...understand the effects of LU types on the distribution of plant species on a macroscale. Aims : The objectives of our study were to quantify the effects of various LU types on the distribution of vascular plant species in Japan and to determine in particular the extent to which LU was an important factor for the distribution of common species. Methods : Based on a logistic regression model and variation partitioning being applied to each plant species, we evaluated the partial deviance by six LU types, four climatic types and three topographic and geological factors for 647 plant species at 14,412 sites in Japan. Results : The effect of LU was significant for species present at multiple sites. Of the six LU types, secondary vegetation and plantation were the most important factors determining species distribution for many species. Conclusions : Our results suggest that distribution of the common species is largely affected by LU on macroscale. The design of LU relating to secondary vegetation and plantations will thus be important in determining changes in the vegetation composition within Japan.
In this study, we reveal the behavior of raccoon dogs and other mammals on two types of latrines: already-existing latrines in the field and artificial latrines created from the feces of a captive ...individual. From September to November 2019, we used camera traps at already-known (eight sites), and artificial latrines (four sites), and recorded the mammalian species that visited, their behavior types, and the duration of time spent at the latrines. Our camera traps detected eight species visits, including raccoon dogs, masked palm civets, and rodents (Muridae). In raccoon dogs, sniffing, urination, defecation, and passing were observed, and the numbers of defecation and passing occurrences were significantly higher in the already-existing latrines. The duration time of the raccoon dogs was significantly longer at the artificial latrine; however, the time decreased as days elapsed. Masked palm civets frequently visited the artificial latrines, where the number of rubbings was significantly higher. The Muridae did not differ in their proportion of foraging behavior between the two latrine types, indicating that both were used as feeding sites without distinction. The results of this study indicate that raccoon dog latrines affect not only raccoon dogs but also other mammals.
We investigated the potential of small pools on the sides of forest roads in the Shonai region of northeastern Japan as breeding habitats for the near threatened species Tohoku salamander (Hynobius ...lichenatus). We surveyed the presence of egg sacs of the salamander in pools from April to June 2022. The relationships between the number of egg sac pairs and environmental factors were analyzed using a Zero-inflated negative binomial model (ZINB). Furthermore, we conducted a population survey of the salamanders in pools where egg sacs were found during August to September 2022 before the metamorphosis of larvae, to determine their survival to larval stage at the egg-laying sites. Egg sacs were detected in 85 out of 250 surveyed pools, suggesting that pools on the sides of forest roads are used as egg-laying sites by the salamanders. The ZINB analysis revealed positive correlation of number of egg sacs with litter availability, water depth, low number of Japanese fire-bellied newts, proximity to forest, and lack of road pavement. Of the surveyed pools where egg sacs were identified, 75 were further examined for the presence of larvae and larvae were found at 20 sites. This suggests that larvae could not survive at many egg-laying sites on the sides of forest roads.
The Heteroptera, or true bugs, forms one of the major insect groups with respect to the very diverse habitat preferences, including both aquatic and terrestrial species, as well as a variety of ...feeding types. The first comprehensive inventory of the Heteroptera at Komaba Campus of the University of Tokyo, or an urban green space in the center of the Tokyo Metropolis, Japan, was conducted.
A total of 115 species in 29 families of the suborder Heteroptera were identified. The area had a high species richness compared with other urbanized and suburbanized localities in Tokyo. The campus is found to show a substantial difference in heteropteran species compositions, despite being close to the other localities surrounded by highly urbanized zones in central Tokyo.
We analyzed whether the relationship between population density and urban land use rate differs depending on the region by the third mesh unit. When calculating the number of urban meshes based on ...population density and land use criteria, the number of urban meshes based on population density criteria was slightly larger than the number based on criteria of land use in many prefectures. However, in Hokkaido, there was atendency that the number of urban mesh is small with criteria based on population density. Pearsonʼs correlation coefficients between population density and urban land use rate were calculated for each prefecture, and as a result, a high value of 0.82 on average wasobtained, but relatively low values of around 0.6 were obtained in Hokkaido and Iwateprefecture. We analyzed whether these differences influence the prediction model of the number of woody plants in Kanto district and Hokkaido. Population density was estimated as a significant variable in the prediction model of Kanto district, but in the Hokkaido the opposite result to the Kanto model was obtained. When population density and urban land use rate are used as an index of urbanization, it will be necessary to recognize that therelationship has regional differences.
We evaluated the environment types of raccoon dog latrine sites in the hilly areas of north-eastern Japan. We conducted a route census in the spring and autumn of 2020 to record the latrine sites and ...analysed the relationship between the presence or absence of latrine sites and environmental factors, namely, topographic position index (TPI), slope, normalised difference vegetation index (NDVI), and vegetation type for each season. To investigate the space use of raccoon dogs, we also conducted camera trapping from July to November 2020 along the spring survey route. We analysed the relationship between the occurrence frequency of raccoon dogs and TPI, slope angle, NDVI, and vegetation type. The analysis showed that latrine sites tended to be located at sites with a high TPI (topography closer to the ridge) in both seasons. However, the occurrence of latrine sites in broadleaf forests was significantly higher in autumn. The frequency of raccoon dogs, based on camera-trap footage, was significantly higher at sites with gentle slopes; although the environment and space used by raccoon dogs at these sites differed. Raccoon dogs possibly select visually and olfactorily conspicuous sites on the ridge as latrine sites to facilitate odour dispersal. In addition, broadleaf forests in autumn are considered important feeding grounds for raccoon dogs, suggesting that the latrine sites were formed near foraging sites.
Identification of focal areas for conservation using hotspot analysis is an effective method of biodiversity conservation planning. In this study, we identified and compared hotspots for various ...environmental stressors and habitat types based on the extinction risk of vascular plant species outlined in the Red Data Book of Japan (2000), at the secondary cell scale (〜10×10km). Because survey bias may influence the apparent effectiveness of conservation efforts in a given area, we statistically evaluated the effect of survey effort. We showed that effective areas for conservation comprise various habitat types. According to a cumulative logit model using conservation effect calculated from vascular plant species, hotspots were distributed in lowlands and in areas with undisturbed habitat and volcanic landforms. However, because they are unique, it is important to assess hotspots for each stressor and habitat type independently. Moreover, we found a positive effect of survey effort for some habitat types; therefore, care must be taken to avoid survey bias among regions and habitat types.
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