The Urban Nature Concept—of What Urban Green Consists of

Urban nature is notably diverse and species rich. This is partially due to the particular ecological conditions provided by the urban environment. Due to the broad spectrum of human activity, the urban environment offers a range of habitats for different species. The “four natures approach” is a simple method for presenting urban nature in a clear and concise manner. It focuses on the particular features of urban nature (fauna, flora and vegetation) and distinguishes between four different “types of nature” based on the degree of anthropomorphic influence that the landscape has experienced. Urban parks, woodlands, forests, gardens, agricultural land, wetlands and new urban wildernesses contribute to urban nature. Each type of nature provides specific urban ecosystem services as benefits for urban residents. These urban nature types have specific structure, design, management, utilization forms, locations and embedding into urban forms. Urban forest refers to the entirety of urban tree stock, irrespective of ownership and is considered a resource and provider of ecosystem services benefitting the city residents. It includes woods and woodlands as well as all trees on both public and private land (street trees, trees in parks, private gardens, cemeteries, brown fields, orchards).