Ecosystem structure can affect human health: a longitudinal study on Green Prescriptions

The role of Nature in supporting human life, health, and well-being has been recognized and appreciated since ancient times and has recently undergone scientific investigation, which highlighted the human dependence on Nature to nurture mental and physical health. Among Nature-based interventions that aim at exposing people to the natural environment, Green Prescriptions (GRx) represent a promising strategy to address human health challenges while respecting the environment, aligning with Planetary Health framework. However, significant gaps remain in our understanding of the specific ecological factors that influence health outcomes during therapeutic activities in natural settings. In particular, it remains unclear how ecosystem structure and functions modulate health responses in individuals. This nine-month pilot study examined the therapeutic efficacy of GRx within a Mediterranean woodland ecosystem, to assess if and how variations in ecosystem structure influence health outcomes in individuals with complex chronic conditions. Using a novel aggregated index to characterize four distinct woodland patches, we identified a gradient in structural complexity where greater ecosystem functionality resulted consistently associated with greater alleviation of psychological and physical symptoms. Notably, health outcomes were independent of weather conditions and participants’ baseline connectedness to Nature, whereas temporal dynamics and the presence of peaks in the productivity of some species influenced both perceptions and physical responses. This underscores the intrinsic role of ecosystem properties and dynamical functions in modulating human health responses, while also suggesting the potential presence of a complex set of signals pervading complex ecosystems that is worth further exploration. The results demonstrated cumulative health benefits, including significant reductions in medication use over time, particularly among individuals with respiratory challenges and chronic pain. Furthermore, participants showed improved environmental awareness and behavior, embracing the interconnectedness principle, which is integral to effective environmental conservation. This study highlights the potential of functional ecosystems to serve as co-effectors in healthcare interventions, advancing the goals of One Health and Planetary Health while reinforcing the importance of preserving ecological integrity.