Limitations of quantified rules in urban forestry

Quantification is fundamental to managing complex systems, particularly in resource management (Walters, 1986). From agriculture to forestry, precise metrics guide decision-making and optimize out- comes. This reliance on quantitative data has become ubiquitous across various sectors of society, shaping modern management practices (Muller, 2018). In urban forestry, quantitative metrics have gained traction, promising to bring clarity and direction to the management of urban green spaces. They also facilitate the communication of management objectives to the public and the reporting of performance against those objectives. Since the 1990s, forest management and policy initiatives worldwide have been dominated by the development of metrics to gauge progress in sustainable forest management. Shortly after the United Nations Conference on Environment and Development in 1992, groups in various regions began working on sets of these metrics in the form of criteria and indicators – for example, the Montreal Process, the ITTO Initiative, the Tarapoto Proposal, the Dry-Zone Africa Process, the Near East Process, the Pan-European Process, and more (Casta˜neda, 2000). In these systems, the criteria represent broad baskets of values that people judge to be important in the achievement of sustainable forest management, and the indicators represent ways of measuring attributes of the criteria for operational assessment of progress. Such work was eventually extended to the level of the forest-management unit (Duinker, 2001), as well as to the domain of urban forests (Clark et al., 1997; Kenney et al., 2011).