We spoke to Professor Martin Dallimer, Chair of Environmental Sustainability at the Centre for Environmental Policy, about how access to pristine woodlands is key to unlocking the mental health benefits of nature.
The UK, like many industrialised countries in the world, is facing a biodiversity crisis.
The State of Nature report of 2023, which provides the most comprehensive overview of species trends across the UK, estimates about 50% of the UK’s biodiversity has been lost since the Industrial Revolution.
A new study led by researchers from Imperial College London, the University of Kent and backed by the Woodland Trust and the ERC, highlights that such a loss may have huge mental health impacts.
Published in Nature Sustainability, the study sought to provide a direct link between biodiversity and human health benefits. Professor Martin Dallimer, one of the co-authors of the study, said: “We weren’t just looking at proximity to green space but at what exactly within that biodiversity contributes to well-being.”
Unlike previous work that studies how access to green spaces can impact mental health benefits, this study delved into how diverse biological features – from a songbird’s melody to the seasonal appearance of bluebells – specifically contribute to our well-being. The researchers described these biological features as ‘effect traits.’
Biodiversity is a win for public health and for nature
90% of people in a survey of more than 10,000 said woodland diversity significantly boosted their wellbeing, highlighting a wide range of sensory experiences.
For instance, 40% of the wellbeing benefits were attributed to natural sounds, such as birds singing and leaves rustling, while visual stimuli like the variety of plant colours contributed to 23.7% of the reported wellbeing.
Moreover, the research delves into the specific traits of biodiversity that people appreciate. The study quantified 102 unique ‘effect traits’ across various species – spanning animals, fungi and plants – that evoked positive responses.
From behaviours (27% of responses), textures (7.3%), and even smells (2.1%), the role that biodiversity played in people’s wellbeing could not be easily boiled down to a single thing.
The findings may serve as a roadmap for conservation efforts. By enhancing these specific features of biodiversity, such as increasing the diversity of sensory experiences in natural settings, policymakers and conservationists can tailor their strategies to maximise public health benefits, while providing a strong evidence base for conservation.
Inequality and access to biodiversity
Though benefits associated with biodiversity were very strong, they were not equally distributed. The richness of wellbeing-associated woodlands was notably lower in more deprived areas, highlighting a concerning trend of ‘green inequality’ where access to biodiverse, healthy woodlands is disproportionately found in areas where people are better off.
“Our findings indicate geographic variations in the quality of woodland available to people,” Dallimer said. “High-quality woodlands, which are often native and ancient, tend to be located in certain regions, creating biodiversity hotspots. However, this also means there are cold spots where high-quality woodlands are absent.”
These insights are crucial for addressing inequalities in access to nature, according to Dallimer, “If policy is aimed to increase woodland cover, it should target these cold spots to ensure that everyone has the potential to experience the well-being benefits that high-quality woodlands can provide.”