A tree language for Rotterdam. Guiding principles for a creative management culture.

In 2024 the management department of the municipality Rotterdam asked Delft University of Technology researchers for a durable and future-proof decision-making method for tree maintenance in parks and plantations, based on Tree Language. Tree language is a typology of urban tree structures, which characterizes the spatial relationship, the grammar between tree species, configurations and plantations (vocabulary, syntax and structure) and their specific situation. It provides a neutral framework for decision-making; the socio-cultural, economic, physical and ecological dimension provide the content. Urban tree structures derive their logic from the anchoring in the longue durée of their development, and from a scale continuity in which the different dimensions play out. Therefore, the method starts from understanding the existing mosaic of plantations, tree types and configurations in relation to each other as the basis for future transformations. To make the tree language operational for management we studied three cases of different sizes and complexity: Buizenpark is small and part of a neighbourhood plantation structure, Valkeniersweide is a clearly defined urban park and Drechterweide is a large forest plantation. We used the case studies to define different steps: determine 1) type of plantation; 2) tree types; 3) configurations; 4) groups of configurations; 5) Proposal for strengthening existing groups and configurations, with a basic and maximum version as a tool for discussion with different actors. This provides a solid starting point for the next two steps, to be conducted in collaboration with the municipal departments: 6) Compare to ongoing plans; 7) Differentiate in time. This asks for two transitions in management paradigms: 1) Spatial dimension as basis; 2) Configuration instead of forest plantation or individual tree as management unit. Merging a landscape architectural and a maintenance perspective, we might speculatively call this method a ‘creative management strategy’.