Ecosystem functions of confined-scale artificial tidal flats in urban areas in Japan: analysis of driving factors for function-based design

Abstract

Restoration of habitats in coastal areas is often designed with the aim of imitating natural habitats. However, it is reasonable to design habitat restoration based on ecosystem services in urban coastal areas. Therefore, in this study, with the aim of establishing a function-based design based on ecosystem services in artificial habitats, an analysis of the driving factors for ecosystem functions was conducted in two artificial tidal flats in the Tokyo Bay. We designed seven ecosystem functions conforming to the categories of ecosystem services. The reference value of each ecosystem function was determined, and scores were assigned to each function. Four environmental factors and six design factors were considered as the driving factors of the ecosystem functions. Moreover, the relationship between the ecosystem functions and driving factors was analyzed using a hierarchical Bayesian model. Considering the environmental factors, the possibility of a feeding shortage in winter is suggested. The ground height and slope were identified as the most important design factors. It is suggested that these design factors can control the five ecosystem functions. The design factors related to management are also considered important. Finally, we discussed the focus points for conducting an ecosystem-function-based design for artificial habitats.