Editorial Introduction: Green Open Space for a Healthy and Comfortable Urban Life

As a city becomes urbanized and achieves high density, urban green space plays an increasingly important role. Urban green space is one of the essential infrastructures in the city. It serves as a healthy and comfortable living environment to urban dwellers as well as its ecological, social and recreational functions. However, it is a difficult task for cities to increase urban green spaces because of expensive land prices and the constant pressure of development. Therefore, the urban green space we already have should be appropriately evaluated and managed to perform to high quality standards.