In a recent paper in the Lancet, Chalmers et al. argued that investment in additional research should always be preceded by systematic assessment of existing evidence. The reason for this is to reduce waste through duplication but also to enhance the likelihood of identifying the most effective research techniques. Ever at the cutting edge, this is something that we in the Beyond Greenspace (BG) team put into action a couple of years ago. Before developing the BG project we embarked on a systematic review of the existing literature which had considered biodiversity’s relationships with good health and wellbeing, the results of which have just been published in the Journal of Toxicology and Environmental Health, Part B: Critical Reviews.

Despite biodiversity’s central role within the ecosystem services we found that this is a surprisingly under researched area; only 17 papers were identified which had addressed the question in any way. These 17 studies were hugely different in aim, design and method, ranging from global epidemiological analyses, to ethnographic work with wildlife tourists in Spain and California. While the review raised some really interesting questions about whether we can legitimately synthesize such disparate types of studies together, we concluded that we can’t yet confidently characterise the relationship between biodiversity and health. This meant that we (not exactly surprisingly for academics) considered that further research was needed!

The results of the review have helped inform, to some degree, the approaches we are taking in the BG project. For instance, the review highlighted that in trying to understand the links between biodiversity, health and well being it’s crucial to consider factors such as geographical scale. So although we found that there is some evidence to suggest that local biodiverse environments promote wellbeing, at a greater geographical scale, for instance when comparing nation states, the relationships may actually be inverse. In those nations where biodiversity loss is greatest health and wellbeing are found to be better. This seemingly unlikely finding is described as the ‘environmentalist’s paradox’. Raudsepp-Hearne and colleagues have argued that there may be four reasons for this:

1. health and wellbeing have not been measured correctly,
2. in western developed countries, where health and wellbeing is greatest, we are less dependent on local biodiversity for food and other services,
3. that our wellbeing has become ‘decoupled’ from nature by technological developments, or
4. that we may not yet be experiencing the negative impacts but that they will become evident in the future.

Some of the ways in which we have tried to take account of these findings in the BG project include conducting the project at several different geographical scales. We will try and assess the consistency of relationships by conducting analyses at the national scale but also at the local through, for example, the Cornwall case study using data from ERCCIS. We are considering temporal factors; we have accessed and are using longitudinal datasets of both the health and environmental variables. We have also tried to design the research in such a way as to be sensitive to some of the other considerations relating to the environmentalist’s paradox, for instance using various different standardised measures of health and wellbeing.

Finally the review highlighted the fundamental importance of a robust, well articulated theoretical framework. This guides the choice of the most appropriate research design, method and outcomes. We found that many of the studies which had been included in the review had little description of how biodiversity was hypothesized to relate to health outcomes. This finding informed a separate piece of work recently published in Trends in Ecology and Evolution. Members of the BG team worked with colleagues at the University of Reading to build a theoretical framework which describes how biodiversity loss may negatively impact on health and wellbeing through fewer cultural ecosystem service opportunities.

While we recognise it’s not practical to set out on a formal systematic review before designing or undertaking each new research project, it has been useful in this case, highlighting gaps in the evidence and particularly important considerations in relation to future research.

Lovell, R., Wheeler, B. W., Higgins, S. L., Irvine, K. N., & Depledge, M. H. (2014). A Systematic Review of the Health and Well-Being Benefits of Biodiverse Environments. Journal of Toxicology and Environmental Health, Part B, 17(1), 1-20