A longitudinal study on population mental health outcomes from tree characteristics, green space exposure in the UK Biobank

The aims of the research project are to investigate how tree characteristics, green space exposure, and residential relocation impact mental health outcomes in the UK.

Our project intends to add household level tree-specific characteristics to update UK Biobank Urban Morphometric Platform (UKBUMP) with historic and up-to-date data, and fill in the research gap by proposing the longitudinal studies on household level environmental exposure and mental health outcomes.

We will focus on the following three key objectives:

• 1) to explore how tree-specific attributes, including tree species, canopy density, and number of trees affect resident’s mental well-being;
• 2) to examine whether moving to areas with more or fewer trees or green space exposure influences mental health
• 3) to identify whether there is a threshold beyond which additional green space or tree cover provides no further mental health benefits.

Although the co-benefits of green spaces to mental health have been well documented, the specific role of trees within these environments remains under-researched. Understanding how tree characteristics contribute to mental well-being could provide further insights for designing green infrastructure in urban environments. Investigating the effects of residential relocation will yield additional evidence illuminating the links between exposure to greenery and long-term mental health. Identifying the threshold of green space benefits will support evidence-based recommendations for planning policies.

To achieve these objectives, we will be linking and updating the environmental exposure data for the UK biobank, the full cohort of the database will be used to maximise statistical power.