Sustainable cities is one of the key topics of the United Nations 2030 Agenda for Sustainable Development. SDG 11 promotes the goal that cities should be inclusive, safe, resilient and sustainable human settlements. In this context, urban ecosystems, namely, Green Infrastructure (GI) can play a key role to enhance ecosystem services. GI improves ecosystem functioning and resilience, protects biodiversity, promotes societal health and well-being. The concept of GI in cities is becoming increasingly important in the development of urban policies since it improves the quality of life while mitigating the adverse effects of climate change. In this paper, we integrate biophysical method and monetary methods using i-Tree Eco software with about 12,000 trees within Bolzano, Italy. Model results are given for five assessed ecosystem services: 1) carbon storage, 2) carbon sequestration, 3) oxygen production, 4) avoided runoff, and 5) air pollution removal. Thus, our results show the significance of urban trees as a key element for better urban planning considering specific species contribution. The findings of this study will increase the awareness on the important role GIs play in urban systems to improve human well-being, informing policy-makers in charge of developing strategies to achieve impelling conservation actions and sustainability goals.