Twenty minutes in a forest reduce cortisol levels by 12-18% (Antonelli, Barbieri & Donelli, 2019). Not a metaphor. Not poetic interpretation. Measurable biochemistry, documented in a meta-analysis reviewing 22 studies, published in the International Journal of Biometeorology.
But the cultures that lived in forests for millennia didn't need a meta-analysis to know what science now confirms. Nature heals. Not as an abstract concept but as a concrete physiological experience: the nervous system regulates, the mind quiets, the body remembers something the urban world made it forget.
At Dynamis, 7 acres of tropical dry forest in Guanacaste, Costa Rica, are not decoration or picturesque backdrop. They are part of the clinical team. Nature here doesn't accompany therapy. It is co-therapist.
The science of the forest: what happens to the body when it enters the green
Research on the effects of nature immersion has reached a volume that can no longer be dismissed as anecdotal. The meta-analysis by Antonelli et al. (2019) found significant cortisol reductions in 20 of 22 evaluated studies. But cortisol is only one of the variables that change when the body enters the forest.
What the research documents: Exposure to forest environments reduces systolic and diastolic blood pressure, decreases heart rate, improves heart rate variability (a marker of autonomic nervous system resilience), and produces a measurable shift from sympathetic dominance (stress) to parasympathetic dominance (restoration). Dr. Qing Li and his team at Nippon Medical School documented that 3-day forest stays significantly increase the activity and number of NK (Natural Killer) immune cells, an effect persisting up to 30 days after exposure (Li et al., 2009). The identified mechanism: phytoncides, volatile organic compounds that trees emit into the air.
Kim et al. (2023) took this research further with a multi-site trial published in Scientific Reports (Nature Group), evaluating nature-based therapy across 11 locations with 7 psychological variables measured. Effect sizes were notable: d=0.903 for stress reduction, d=0.728 for anxiety, d=0.583 for depression. For context, an effect size of 0.8 is considered large in clinical research.
Kaplan's Attention Restoration Theory (1995) offers a complementary cognitive explanation. Urban environments demand what Kaplan called "directed attention," a cognitive resource that fatigues. Nature offers "soft fascination": stimuli that capture attention without effort, such as the movement of leaves, the sound of water, light filtering through branches. In that effortless fascination, fatigued attention restores itself. It's not that nature "does" something. It's that it stops demanding what the urban world demands constantly.
The tropical dry forest: an ecosystem of transformation
Most studies on shinrin-yoku and nature-based therapy have been conducted in temperate forests of Japan, South Korea, and Europe. Guanacaste's tropical dry forest is a fundamentally different ecosystem, and that difference has specific therapeutic implications.
The tropical dry forest is an ecosystem of cycles. During the dry months, trees lose their leaves. The landscape becomes austere, apparently inert. It looks like death. But it isn't. It's energy conservation, redirection of resources toward the roots, invisible preparation for what's coming. When the rains arrive, the transformation is explosive: within weeks, the entire forest turns green. What seemed dead was accumulating life.
Few ecosystems offer as precise a metaphor for the therapeutic process as the tropical dry forest. The periods of inner drought, those moments when it seems like nothing is happening, that the work isn't advancing, that everything has stopped, are actually periods of underground accumulation. The transformation, when it comes, arrives like the rains of Guanacaste: rapid, green, inevitable.
The trees of Dynamis' sacred terrain are presences with their own character. The guanacaste, Costa Rica's national tree, with its expansive canopy creating domes of shade. The ceiba, axis mundi of Mesoamerican cosmology, with roots that resemble cathedral buttresses. The pochote with its protective thorns. Each offers a different quality to the therapeutic space: shade, verticality, protection, openness.
The tropical dry forest's biodiversity generates an extraordinarily rich sensory landscape. Bird sounds that change with the time of day. Aromas that intensify after rainfall. Textures of bark, earth, leaves. Light that filters differently depending on the season. This sensory richness isn't decorative. It's regulation: the nervous system receives complex, non-threatening information, exactly what it needs to recalibrate.
Ecotherapy in practice: more than walking among trees
It's important to distinguish ecotherapy as a therapeutic modality from simple outdoor recreation. Theodore Roszak (1992), who coined the term "ecopsychology," proposed that the separation between humans and nature is not merely an environmental problem but a source of psychological pathology. Ecotherapy, within this framework, is not simply "going to the park." It is a clinical intervention with intention, structure, and professional accompaniment.
At Dynamis, ecotherapy is practiced through specific modalities. Conscious walking is not a stroll: it is a moving mindfulness practice where each step is an opportunity for contact with the present. Sit spots (extended observation points) invite remaining in one place in the forest for an extended period, without agenda, without objective, observing what emerges when the mind stops searching. Outdoor somatic work uses the natural environment as regulator: the earth beneath the body, the sound of the river as anchor, the wind as reminder that the world breathes with you.
These practices integrate with sessions at Healing Studio. The forest doesn't replace the office. It extends it. What emerges in session can be taken to the forest for bodily processing. What emerges in the forest can be brought to session for verbal integration.
Stephen Porges (2011) offers a neurophysiological explanation of why this works. His Polyvagal Theory proposes that the nervous system constantly evaluates environmental safety through a process he called "neuroception." In a natural environment free of artificial threats, such as traffic noise, screens, and social demands, the nervous system detects safety and activates the ventral vagal circuit: the physiological state associated with calm, social connection, and restoration. Nature doesn't "relax" the way a massage relaxes. It recalibrates the nervous system at a more fundamental level.
Nature as co-therapist in the retreat
In a retreat at Dynamis, the tropical dry forest is present at every moment of the process. The Maloca was designed so that architecture and nature converge: it is not a building that excludes the forest but a space that invites it in. The cabins are nestled within the forest, surrounded by trees, with the nocturnal sounds of the ecosystem as company.
The ecotherapeutic experience at Dynamis: Each retreat integrates ecotherapy practices as part of the clinical program: conscious walks along dry forest trails, outdoor somatic work sessions, contemplative observation sit spots, and moments of silence in nature between sessions. The professional team accompanies these experiences with the same clinical intention applied in office sessions. The forest is not a break between sessions. It is a session of a different kind. Check upcoming dates on our events calendar.
What participants consistently report is something no human therapist can replicate: nature doesn't interpret, doesn't analyze, doesn't judge. It simply is. And in that presence without agenda, something in the nervous system releases. Not because it's asked to but because the environment communicates, at a pre-verbal level, that it is safe to do so.
Final reflection
Nature is not a complement to therapeutic work. It is co-therapist. Stigsdotter et al. (2018) demonstrated in the British Journal of Psychiatry that nature-based therapy can be as effective as cognitive-behavioral therapy for stress. The 7 acres of tropical dry forest surrounding Dynamis are not a pretty backdrop for Instagram. They are a member of the clinical team that works in silence, without office hours, with every person who walks among its trees.
If you're looking for a space where science and the earth work together, we invite you to experience it.
Explore our retreats Discover the sacred terrain
Frequently asked questions
What is ecotherapy and how is it different from simply being in nature?
Ecotherapy is a therapeutic modality with clinical intention, structure, and professional accompaniment. While a walk in the park can be relaxing, ecotherapy uses nature as a therapeutic tool within a clinical framework: there are objectives, specific practices (conscious walking, sit spots, outdoor somatic work), and a professional who accompanies the process. At Dynamis, ecotherapy integrates with individual therapy sessions.
Is the tropical dry forest different from other forests for therapy?
Yes, in important ways. The tropical dry forest offers an ecosystem of intense cycles (drought and renewal) that functions as a living metaphor for the therapeutic process. Its biodiversity generates a particularly rich sensory landscape. And the warm tropical temperature allows year-round outdoor practices, something temperate forests cannot offer in winter.
Do I need to be in good physical condition to participate?
No. Ecotherapy practices at Dynamis adapt to each participant. Conscious walking is not hiking: it's walking slowly with attention. Sit spots involve sitting and observing. Outdoor somatic work is done lying down or sitting on the ground. No special physical condition is required, only willingness to be in the natural environment.
Does ecotherapy work for anxiety and depression?
The evidence supports it. Kim et al. (2023) documented medium to large effect sizes for anxiety (d=0.728) and depression (d=0.583) in a multi-site trial published in Scientific Reports. Stigsdotter et al. (2018) demonstrated efficacy comparable to cognitive-behavioral therapy for stress in a controlled trial. At Dynamis, ecotherapy is combined with individual psychotherapeutic work to address these conditions integratively.
Can I combine ecotherapy with individual therapy sessions?
That is exactly how we do it. Sessions at Healing Studio and ecotherapy practices complement each other: what emerges in session can be processed in the forest, and what emerges in the forest can be integrated in session. Contact us to design a program tailored to your needs.
References
Antonelli, M., Barbieri, G., & Donelli, D. (2019). Effects of forest bathing (shinrin-yoku) on levels of cortisol as a stress biomarker: A systematic review and meta-analysis. International Journal of Biometeorology, 63(8), 1117-1134.
Chalquist, C. (2009). A look at the ecotherapy research evidence. Ecopsychology, 1(2), 64-74.
Kaplan, S. (1995). The restorative benefits of nature: Toward an integrative framework. Journal of Environmental Psychology, 15(3), 169-182.
Kim, S., Choi, J., Kim, Y., Jeong, J., Park, E., Yoo, R., ... & Lee, S. (2023). The effectiveness of nature-based therapy for community psychological distress and well-being during COVID-19: A multi-site trial. Scientific Reports, 13, 22637.
Li, Q., Kobayashi, M., Wakayama, Y., Inagaki, H., Katsumata, M., Hirata, Y., ... & Kawada, T. (2009). Effect of phytoncide from trees on human natural killer cell function. International Journal of Immunopathology and Pharmacology, 22(4), 951-959.
Porges, S. (2011). The polyvagal theory: Neurophysiological foundations of emotions, attachment, communication, and self-regulation. W.W. Norton.
Roszak, T. (1992). The voice of the Earth: An exploration of ecopsychology. Simon & Schuster.
Stigsdotter, U. K., Corazon, S. S., Sidenius, U., Nyed, P. K., Larsen, H. B., & Fjorback, L. O. (2018). Efficacy of nature-based therapy for individuals with stress-related illnesses: Randomised controlled trial. British Journal of Psychiatry, 213(1), 404-411.
