The preservation and expansion of urban green spaces necessitate the design of deterrent yet expert-driven policies to prevent the indiscriminate felling of trees, particularly in a metropolis like Tehran. One of the policy instruments in this domain is levying fees based on the ecological value of trees; however, the existing formula faces economic, ecological, and legal challenges that undermine its efficacy. From an economic dimension, base figures and adjustment coefficients lack a transparent and up-to-date basis, and the presence of coefficients below one can be interpreted as a "discount for tree felling." Furthermore, tying the value of a tree to the regional property price creates value conflicts and leads to unequal assessments of ecosystem services. From an ecological dimension, the indicators determining tree value are limited, and factors such as tree health, canopy size, evergreen or deciduous nature, the role in mitigating air and noise pollution, and the habitat significance of species are inadequately integrated into the calculations. From a legal perspective, ambiguities persist regarding infractions, legal proceedings, replanting mandates, the allocation of collected fees, and conflicts between certain bylaws and other regulations. Remedial strategies emphasize the redesign of the fee formula through precise species classification and ecological valuation, the transparency of urban coefficients, mandatory six-month reporting on the utilization of fee revenues, the clarification of special circumstances (natural disasters, intentional versus unintentional destruction), and the establishment of a monitoring and periodic review system for the decree to enhance deterrence and environmental justice.