Humans have long benefited from nature’s offerings. But beyond being an essential source of food, water and raw materials, the natural world can contribute to people’s overall well-being through a host of intangible effects — and, according to new research, there are many more critical connections between humans and nature than one might think.
After reviewing hundreds of scientific papers on “cultural ecosystem services,” or the nonmaterial benefits of nature, researchers have identified 227 unique pathways through which people’s interactions with nature can positively or negatively affect well-being, according to a paper published Friday in the peer-reviewed journal Science Advances.
The paper is believed to be the first of its kind to provide a comprehensive framework for understanding and quantifying the complex ways in which people and nature are connected. And its findings could have significant real-world implications, said Lam Thi Mai Huynh, the paper’s lead author and a doctoral candidate at the University of Tokyo.
“For the modernized world, people tend to disconnect from nature,” she said. “For ecosystem management, the best solution, the most sustainable solution, is to connect people back to nature and let the local people be the ones who help to maintain and manage the ecosystem services.”
For Huynh, the ambitious research — an undertaking that even her academic supervisor initially thought might not be possible — stemmed from a desire to improve understanding of the complicated underlying processes behind how nature’s intangible effects — such as opportunities for recreation and leisure or spiritual fulfillment — have an impact on well-being. One major challenge, though, is that much of the existing scientific literature on cultural ecosystem services has been “highly fragmented,” the review noted.
“You have all sorts of different people looking at [the intangible benefits of nature] through a different lens,” said Alexandros Gasparatos, an associate professor at the Institute of Future Initiatives at the University of Tokyo who co-authored the paper. Although having diverse research is critical, he said, “it becomes a little bit difficult to bring everything together.”
But the new study, a systematic review of roughly 300 peer-reviewed scientific papers, creates “an excellent knowledge base,” Gasparatos said.
“The whole point of doing this exercise is to understand the connection,” he added. “We give names to phenomena.”
The review breaks down the hundreds of possible links between individual aspects of human well-being (mental and physical health, connectedness and belonging, and spirituality, among others) and cultural ecosystem services, such as recreation and tourism, aesthetic value and social relation. The researchers then went a step further and identified more than a dozen distinct underlying mechanisms through which people’s interactions with nature can affect their well-being.
Researchers found that the highest positive contributions were seen in mental and physical health. Recreation, tourism and aesthetic value appeared to have the greatest impact on human health through the “regenerative” mechanism, or experiencing restorative effects from being in nature such as stress relief, according to the paper. Meanwhile, the highest negative effects are linked to mental health through the “destructive” mechanism, or direct damages associated with the degradation or loss of cultural ecosystem services, the researchers wrote.
“In reality, you don’t just have one pathway,” and the effects aren’t always positive, Gasparatos said. “It’s not that if I go to the forest, I receive one thing.”
A well-designed park, for example, can be a place for recreation and leisure as well as connecting with other people. You might also find yourself appreciating the sight of towering trees and lush greenery or birds and other wildlife. On the other hand, a poorly maintained natural space could lead to an ugly or visually threatening landscape that might make you feel uncomfortable or scared to be there.
The paper can provide a road map of sorts, Huynh said, to help people, particularly decision-makers, understand that there are not only various intangible benefits to interactions with nature, but also how to try to achieve them.
“If we understand the underlying process, we can help to design better interventions for ecosystem management,” she said. “We can help to improve the contributions of nature to human well-being,” in addition to potentially bettering sustainable management practices and eliminating some of the negative effects on well-being.
The research was widely applauded by several outside experts who were not involved in the work.
“It’s a long time coming to have a study like this that makes some of these linkages a little clearer,” said Keith Tidball, an environmental anthropologist at Cornell University. “This stuff has been scattered all over the place for a long, long time, and this paper takes a huge step forward in sorting out what has been previously pretty muddled.”
Anne Guerry, chief strategy officer and lead scientist with the Natural Capital Project at Stanford University, agreed. “They did a really nice job of bringing together extraordinarily diverse literature,” she said. It’s been a challenge, she noted, among researchers to be able to present the science in a way that reveals where and how nature provides the greatest benefits to people, which could in turn help “inform and motivate investments in conservation and restoration that lead to better outcomes for both people and nature.”
For instance, the research could have an impact on the role nature potentially plays in human health. “What this is going to be seriously useful for is to be able to continue to work to make the case that physicians and clinicians can actually prescribe outdoor time, outdoor recreation, even outdoor space because of these pathways that they’ve identified in this paper,” Tidball said.
In one scenario, elements of this work could ultimately be included in the Diagnostic and Statistical Manual of Mental Disorders, said Elizabeth Haase, chair of the American Psychiatric Association’s Committee on Climate Change and Mental Health.
“That sets us up to be able to say that when we facilitate this kind of interaction with nature, you see this kind of benefit, and then prescribe these kinds of natural experiences, or have policies that say that you’re really depriving someone of their mental health if you destroy these natural landscapes,” she said.
But the review does have limitations, prompting some experts to caution against overinterpreting or overemphasizing its results.
One potential issue is that the existing research included in the review disproportionately focuses on individuals rather than groups.
“There are multiple times where something might be really good for an individual, but overall for the community, it might not be very good at all,” said Kevin Summers, a senior research ecologist with the Office of Research and Development at the Environmental Protection Agency.
“In many cases, there can be unintended consequences for things that look like very simple, straightforward decisions,” Summers added.
Other research gaps should also be taken into account, Guerry said. While the review suggests that some connections between certain human well-being characteristics and cultural ecosystem services appear stronger than others, it doesn’t mean those other relationships might not be significant, she said.
“We have to be careful in terms of oversimplifying the results and thinking that a lack of a documented relationship in this paper means that something isn’t important,” she said. Instead, it may mean that “it hasn’t been studied and we haven’t found ways to quantify it and bring it into the scientific literature and out of our sort of implicit understanding.”
The researchers addressed the limitations of their work, noting in the paper that future research “should explore in-depth how these pathways and mechanisms manifest in less studied ecosystems and understand their differentiated effects to various stakeholders.”
In the meantime, though, the findings serve as an important reminder of nature’s necessity.
“It can justify, very well, a mind-set like, ‘Let’s invest in nature because it has all these benefits,’ ” Gasparatos said.
With such strong positive benefits related to creativity, belonging, regeneration and more, “it’s easy from this paper to feel that your constitutional right to the pursuit of happiness requires a country to preserve natural spaces,” Haase added.
In a time when many people are becoming further separated and distanced from “our ecological selves,” efforts to link humans and nature are not only interesting in terms of science, philosophy or ethics, Tidball said, but “there are also human security implications here that are significant.” And, he said, if steps aren’t taken to reconnect people with nature, the consequences could be dire.
“If we continue on a pathway as a species of being in a state of ecological amnesia,” he said, “we’re going to find ourselves out of habitat and out of time and, therefore, out of luck.”