Both case study cities perform relatively well in regards to all GI principles and at least partially mirror the theoretical discourse on green infrastructure planning. Nevertheless, the cities could intensify the consideration of GI principles in all three dimensions. Transdisciplinarity—in our case, ranging from interdepartmental cooperation to collaborative planning with stakeholders and citizens—especially shows room for improvement. Although overcoming the structure and tradition of separately working municipal departments is challenging (Primmer and Furmann 2012) and extending public participation requires considerable commitment and resources, transdisciplinary planning is increasingly viewed as an instrumental component of land use management (Antrop 2006; Angelstam et al. 2013).
In relation to connectivity, the case study shows that cities like Berlin already consider the importance of an interconnected system of green and open space that serves multiple purposes. This is not surprising as green space systems, such as green rings and habitat networks, have long been discussed in Germany and many other European countries.
Unlike Sandström’s (2002) conclusion for green structure planning in Sweden—that planners do not seize the multifunctional potential of urban green and still remain in traditional realms of cultural issues of urban green—the analyzed documents for green planning, such as the Urban Landscape Strategy exhibit a comparably broad thematic scope. As the documents analyzed by Sandström mainly originated in the 1990s, our results may be indicative of an increased emphasis on multifunctionality. The coverage of all groups of ecosystem services by both cities also supports our assessment that both cities—with potential for improvement—can be considered as familiar with holistic perspectives. However, the question of how intertwined and synergistic these different functions and services are discussed cannot be answered with our study approach.
Due to our selection of only two case study cities, the lens of implementation we have provided is limited in representativeness.* Additionally, our document analysis approach can only illuminate fragments of the planning process, namely the ones that are present within official planning documents. To get more complete insights, for example, if the level of awareness is truly higher in one city or whether the theoretical approaches might be understood by planners but not indicated in plans (see, e.g., Niemelä et al. 2010), a multi-method approach would be necessary, including interviews with stakeholders. Nevertheless, our study represents a first step toward an evaluation of gaps between theory and practice of green infrastructure planning and promotion of ecosystem services in urban areas based on empirical data that could be extended to other cities. Such an analysis can be used to deduce research gaps in terms of theory and tool development that hinder an exchange between research discourses and real-world planning.