Even though the effects of nature on human wellbeing have been investigated fairly extensively, little research has been conducted on the potential differences between managed and natural forests. Furthermore, there is reasonably little research on how an individual’s mental health affects their restorative experience in an authentic forest environment. In her doctoral thesis examined at the University of Helsinki, Jenni Simkin, a researcher working at Natural Resources Institute Finland, examined the impact of forests managed in different ways on human wellbeing. The study involved three managed forests and one natural old-growth forest. In field experiments, 66 participants were taken to each of the four forests.
Simkin found that, while all four forests had a restorative effect, the oldest, an over 120-year-old natural forest and a roughly 100-year-old mature commercial forest were the most restorative. A young, approximately 40-year-old, commercial forest provided a restorative effect for the first 15 minutes after which the experience of restoration did not intensify. An urban, approximately 90-year-old, recreation forest provided a better experience of restoration than the young forest but not to the extent of the other two older forests. The restorative effect of the urban forest was weakened by urban noise and the abundance of other people enjoying the outdoors as well as other potential factors, such as pollution. The perceived beauty and diversity of forests were highlighted as important factors explaining the restorative experience.
A follow-up study also found a statistically significant link between the current work stress of participants and restoration in the old-growth natural forest and the mature commercial forests, with the effect at its strongest in the natural forest. A link, albeit small, was also found between a heightened risk of depression and restoration in the natural old-growth forest. This link was not found in the other forests. Therefore, it seems that people who experience their day at work to be stressful benefit more from visits in older forests. According to Simkin, however, more research is needed to better understand why the link between a stronger restorative experience of individuals in the natural old-growth forest and the risk of depression emerged. The study did not specifically ask about depression diagnoses, and based on a self-assessment questionnaire, individuals with a heightened risk of depression did not participate in the study.
Access to nearby forests is important for the wellbeing of urban dwellers
The study provides valuable information on how modifying natural environments, in this case through forest management, may also be linked with human wellbeing.
“In Finland, where more than 80% of forests are forested and less than 5% are natural forests, it would be important from the perspective of human wellbeing to preserve the remaining old-growth forests and to promote the share of older forests especially near inhabited areas. Commercial forests could be a significant resource for the maintenance of public health if their rotation periods could be extended, in other words postponing regeneration cutting so that the trees have time to become sturdy and the old-growth forest species to diversify. Since all of the forests in the study had restorative qualities, dwellers will likely benefit also from local forests whose quality is not among the most restorative. However, the increasing density of cities poses a threat also to a very valuable forest nature,” muses Simkin.
The study is topical, not only because of the densification of urban areas, but also because there is a lively debate ongoing on the conservation of old forests and the rotation periods of commercial forests.
“As mental health issues are becoming increasingly common, it is important to find ways to curb them. One viable way could be to increase the use of older forests, whether they be natural or commercial,” Simkin says.
The study was one of the few where the participants were brought into actual forests for a comprehensive forest experience. The study also included a natural forest whose wellbeing effects went unexamined.
Further research is needed on the effects of various types of forests on wellbeing, such as the significance of the dominant tree species and management methods – for example, continuous cover forestry – on the wellbeing of people.
Public examination of a doctoral thesis:
Jenni Simkin defended her doctoral thesis entitled Forests that restore - the effect of managed versus natural forests on human psychological restoration on 16 May 2025 at 13.00 in the Faculty of Agriculture and Forestry of the University of Helsinki. The public defence will take place at Biocenter 2, room 2041, Viikinkaari 5.
Her opponent is Associate Professor, Docent Anna María Pálsdóttir from the Swedish University of Agricultural Sciences, and Tuula Jyske as the custos
The doctoral thesis is also available in electronic form through the Helda repository.