Relationship Between Urban Tree Diversity and Human Well-being: Implications for Urban Planning

Green spaces and trees are key elements for enhancing human well-being in cities. Despite recognizing the significance of urban greenery for human health, the role of urban biodiversity in shaping well-being remains poorly understood. This study focused on the interplay between tree genera diversity, perceived urban biodiversity, and the subjective well-being of urban residents in Karlsruhe, Germany. A map-based online questionnaire involving 302 participants investigated well-being locations and perceptions of biodiversity. Tree genera diversity was assessed for nine genera using remote-sensing and ground data. A novel approach of spatially correlating societal mapping results and tree genera cover maps revealed a clear preference for green spaces in the built-up urban environment. The relations between computed tree genera diversity and subjective well-being were unclear. However, there was a significant relationship between the perceived biodiversity of urban green spaces and subjective well-being. The amount of tree cover, the abundance of large trees, as well as the perceived species diversity beyond tree genera, lead to increased well-being of the urban population. At the same time, a perceived unkemptness of urban areas had a negative effect on the residents’ well-being. This should be considered in future research and the design of urban green spaces.