In 2025, EHN launched the Healthy Ecosystems, Healthy People Initiative to help strengthen the evidence base for how conserving biodiversity and restoring ecosystems may influence human health.
At its core, the initiative seeks to rigorously test what we call the EHN Hypothesis—that ecological restoration can deliver tangible and quantifiable public and clinical health benefits. The goal is to inform actionable strategies that expand the scope, improve the quality, and enhance the impact of ecological restoration efforts globally. We aim to make our findings broadly accessible by publishing in journals read by medical and public health professionals.
While decades of research show that degraded environments can harm health—and that exposure to green spaces supports mental and physical health—there’s still a critical, unanswered question: Can the conservation of biodiversity and restoration of degraded ecosystems lead to measurable improvements in human health?
This question is difficult to test, and few have attempted it. While some evidence suggests that nature-based activities can benefit human health, there are also cases where the benefits of “greening” may be overstated or even harmful, such as when allergenic trees are planted in urban areas. Empirical evidence to confirm or disprove our hypothesis remains scarce. Without rigorous, data-driven studies, the full value and still-untapped potential of restoration efforts will continue to be overlooked in policy and funding decisions. It is critical to fill this gap by demonstrating whether and in what ways conservation of biodiversity and restoration of degraded ecosystems influences human health.
Through the EHN global action network, member organizations, institutions, and sites are working together to collaborate, secure funding, exchange knowledge, and promote education—activating pilot projects that demonstrate how to foster both healthy environments and healthy people concurrently.
We’re currently seeking new partners and demonstration sites.
We are co-developing, with health and restoration researchers and practitioners, a coordinated research program to produce rigorous, transdisciplinary studies that explore the health effects of participating in or being exposed to sites where ecological restoration has been or is being undertaken.
Because the health impacts of restoration may vary depending on ecological and cultural context, this research will be carried out across a wide range of biomes, ecosystems, and communities. Only by working in diverse settings with our collaborators can we test site-specific hypotheses and build a strong, evidence-based understanding to guide policy and practice.
If you are developing—or envisioning—a project that could contribute to building the evidence base connecting ecological restoration and human health, we invite you to share it with us. By submitting your project for consideration as a core partner site, we can explore how best to support your work and align it with broader research and practice goals.
We are especially looking for demonstration projects that meet the following criteria:
- A site or network of sites where restoration, conservation, or greenspace management are being undertaken, in proximity to a human population or engaging people that may be affected by or benefit from these activities.
- A clear and actionable research question, ideally driven by the community and local health professionals, addressing the relationship between environmental and human health. This question should have the potential to generate measurable outcomes within a five-year timeframe.
- Demonstrated capacity — or a clear, feasible strategy to build the necessary capacity — to undertake research including data collection, data analysis, and manuscript writing.
- Interest in being part of a multidisciplinary international collaboration, including potential for future grant funding and additional collaborations through the EHN network.
