Urban trees are highly important for several aspects of the city life, influencing the thermal and psychological comfort, filtering pollution and helping to keep air humidity forming "aerial rivers". In this article, I use the city of São Paulo as a model to discuss issues related to the potential influence of urban trees on the above-mentioned aspects and also the potential of inclusion of urban trees in the context of the economical performance of the city. All this can only happen if urban trees are planned on a strong scientific basis using a systems thinking approach that will help to integrate trees into the city processes. Using data from the City Council (Prefeitura da Cidade de São Paulo) on the index of green per inhabitant, I show that there is a deficit of trees in the Central and East side of São Paulo that deserves attention when planning for the future. I also point out the importance that urban trees have due to the production of water vapor to an extent comparable with the two main rivers in town (Tietê and Pinheiros). Finally, I raise some points that need to be part of the first steps of a plan for urban trees management that should be capable to integrate urban forests with urban life. All that has to be based on a systemic vision that would take into consideration the existence and role of urban trees in cities of the State of São Paulo.
Urban trees; Urban forests; Water; Photosynthesis; Megacities; Systemic thinking; Pollution; Heat island; Climate change; São Paulo
