Why study urban biodiversity? Evidence from Japanese case studies

Abstract

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.