Urban trees improve the living quality and health of citizens, while also providing many Ecosystem Services. However, the value of trees gets easily undermined or lost against other competing factors in urban planning, largely because of a lack of visibility of tree information in urban information systems. This is particularly the case with tree roots, which often take up the same space that city planners and constructors are targeting when building or maintaining critical urban infrastructure. As tree roots are invisible to citizens and urban stakeholders, it is generally poorly understood how e.g. damage to tree roots during excavations will affect tree health and can cause tree death. As a solution to these problems, we propose to produce algorithmic 3D models of local tree roots for urban digital twins, together with data collection and model updating procedures, root growth prediction models and solutions for city data formats and interoperability. The models will comple-ment aboveground algorithmic 3D tree models, help to model the life and well-being of trees, and allow city stakeholders to view, use and study tree root systems and their needs via 3D city models, digital twins and VR/AR applications.
