Human Health & Plants Research: Can Psychological and Physical Connections with Nature Link Human Well-being with Conservation?

Dr. Charles Guy

A systematic review does the following: 1, exhaustively searches and collects all published studies related to a given topic based on a defined set of keyword and experimental design criteria, 2, reviews the quality of included studies, and 3, summarizes the collective results.  A meta-analysis is a statistical analysis of the pooled collective results of the included independent studies contained in a systematic review.  Systematic reviews with meta-analysis are valuable in biomedical sciences to help inform and guide the development of healthcare applications and policies.

Barragan and colleagues1 conducted a systematic review of meta-analysis studies that focused on the psychological and physical connections to nature regarding human health and well-being that promoted conservation of natural environments.  The authors found 16 meta-analysis studies representing a remarkable 832 individual studies from 362 bibliographic records screened.  Altogether, the 16 studies reported 1876 experimental treatment effect size estimates.  This supersized collection of studies offered an unusual opportunity to provide novel insight regarding human connections with nature and pro-conservation mindsets and behaviors.  The included studies covered a wide range of research areas, from conservation to economics to general health to psychology.  Given the vast diversity of the individual studies, research areas, objectives, experimental designs, and outcomes, the authors categorized several factors within studies to help gauge and understand treatment effect size heterogeneity.

Nearly all studies reported were conducted in North America, Europe, and Asia, and 80% focused on only adults.  No studies were reported from the African continent.  Half of the meta-analysis studies reported experimental findings, while the other half reported correlational studies.  Nine of the meta-analysis studies were based on a “nature for people” framework, while five investigated a nature connection to a conservation perspective, and three addressed results in a biophilic evolutionary context.

The overall meta-analysis of the 16 meta-analysis studies revealed significant positive treatment effects regarding physical connections with nature on mental, physical, and social health.  The present study also showed a positive psychological connection with nature with respect to pro-environmental behaviors.  Natural sounds in species-rich natural environments associated with nature-based mindfulness had one of the greatest treatment impacts on human health.

Given the vast diversity of studies contained in the 16 meta-analysis studies, it is not unexpected that treatment effect size varied widely.  Barragan-Jason and colleagues1 conclude two critical factors that are beneficial in leading to behaviors and values that promote nature conservation/sustainability and human health are high biodiversity, particularly acoustic biodiversity, and engaging in nature-based mindfulness activities.  The authors further conclude that enhancing such physical and psychological connections to nature is key to achieving greater conservation aspirations.

1Barragan-Jason, G., Loreau, M., de Mazancourt, C., Singer, M. C., Parmesan, C. (2023). Psychological and Physical Connections with Nature Improve Both Human Well-being and Nature Conservation: A Systematic Review of Meta-Analyses. Biological Conservation, 277, 109842.

Charles Guy, Emeritus and Courtesy Professor

Department of Environmental Horticulture, University of Florida

Steering Committee, Wilmot Botanical Gardens, University of Florida