Collaboration needed on nature and wellbeing links
Scientists need to capitalise on a growing body of evidence showing a link between biodiversity and human wellbeing, a US review has suggested.
It said rapid progress could be made if there was better communication and collaboration between researchers and public health and land-use officials.
A global research project was recently launched to examine the impact of urban policies on human health and wellbeing.
"This is something that had held my interest for some time, that is the condition of the general environment and human wellbeing in the broadest sense," explained co-author Paul Sandifer, former chief science advisor for the National Ocean Service at the US National Oceanic and Atmospheric Administration (Noaa).
"I have long had a feeling of that there were connections between exposure to the natural environment and improved physiological and psychological health."
Dr Sandifer said he and his fellow co-authors decided if it was possible to "tease out" peer-reviewed examples of "biodiversity providing advantages for human health".
"If there was, how we might usefully categorise those relationships - what were the characteristics and mechanisms that brought about that change," he told BBC News.
One of the main challenges the team faced was attempting to identify key literature from a vast quantity of different sources.
"A little bit comes out in landscape literature, a little bit comes out in psychology literature, a little bit comes out in ecological or city planning publications but rarely are these things put together and assesses what one could do with the knowledge from around the scientific sphere," explained Dr Sandifer, who has recently retired from his Noaa post.
"One of the main findings of the review for me and for my colleagues was the huge amount of information indicating mostly positive health responses of some kind - mainly psychological," he observed.
"Among the vast array of research, there are a number of carefully crafted studies that truly demonstrate cause and effect.
"These carefully define the characteristics of biodiversity or nature that might be of interest and what the effect might be on mental or physiological wellbeing or health. Finally, they looked at what the process was in which that possible effect might be mediated.
"The one area we identified where there was a fair amount of new evidence was the study of microbiota and its influence on inflammatory diseases.
For example, a study in 2012 suggested a lack of exposure to a "natural environment" could be resulting in more urban dwellers developing allergies and asthma.
Finnish scientists said certain bacteria, shown to be beneficial for human health, were found in greater abundance in non-urban surroundings.
But Dr Sandifer said his team's review found that there was still "a lot left to be done" even in this field of research.
He added that there was a considerable amount of research looking at the difference between good and bad green spaces in urban areas but almost no data at all when it came to marine or coastal environments.
"Probably the one area where rapid progress could be made is improving communication and collaboration between land-use and city planners, people involved in public health - both research and application, and their connection to ecological science.
"Ecologists are within their field and rarely reach outside it. Biomedical researchers, it seems, rarely have the time to reach out. There is a gap between the two where we really need to do a much better job of communicating.
But there were signs of progress in the right direction, he suggested: "The American Public Health Association has a new policy recognising the value of nature."
But he added: "This needs to be international - the UK, such as the University of Exeter's European Centre for Environment and Human Health, has done a vast amount of research on the value of green spaces."
At the end of 2014, a global scientific research programme was launched in China to examine the unintended consequences of urban policies on human health and wellbeing.
The Urban Health & Wellbeing Programme aimed to better understand what made a "healthy urban environment".
Dr Sandifer concluded: "The communication links is the first step to getting well-rounded policies and getting the value of nature out to wider communities, such as policymakers, than it does at the moment.
"I think that would then drive the availability of resources to do more studies."