FEATURE: Therapeutic Horticulture and Sustainable Cities

Can urban areas make you unwell?

The answer is yes, according to experts during the recent ASEAN workshop on Therapeutic Horticulture led by Singapore’s National Parks Board (NParks) and the ASEAN Centre for Biodiversity (ACB). The virtual workshop gathered experts who shared the restorative benefits that people can reap from urban green spaces. 

Discussing the link between urbanisation and mental health, Dr. Agnieszka Olszewska-Guizzo, president and co-founder of international research group NeuroLandscape, cited a meta-analysis showing that the urban environment is increasing the risk of any mental disorder by as much as 39 per cent. 

From March 2019 to September 2020, NeuroLandscape conducted a study in collaboration with the NParks on the effects of landscapes on the brain activities of selected respondents in Singapore. The study, which measured self-reported moods and pleasantness; brain activity; and the Contemplative Landscape Model (CLM) scoring, showed that moods and brain activity change after being exposed to certain landscapes. 

The respondents’ feelings of tension and anger dropped after being exposed to green spaces in a residential area in Singapore. Fatigue, depression, and confusion also dropped for those who were exposed to therapeutic gardens, thereby improving their overall mood. 

Nature’s impacts on the brain

Among the other findings of the study is the effect of the physical environment on the human mind and emotions. Looking at urban scenes or landscapes prompts the brain to release specific cognitive resources to process sensory stimuli, which according to Olszewska-Guizzo, is indicated by the heightened oxy-hemoglobin (Oxy-HB), or the oxygen-carrying form of hemoglobin in the blood vessels in the brain. Oxy-HB among respondents exposed to the therapeutic gardens are much lower, indicating less cognitive strain, meaning they are more relaxed in this setting. Meanwhile, respondents who were exposed to the busy urban areas, where “not even the sky was visible” and even in the residential green areas showed a significantly higher oxy-HB indicating higher brain activity.  

Additionally, the study also found that in the sub-samples of 26 individuals with clinical depression, there is an increased alpha power in the brain’s right frontal cortex which is associated with positive emotions, as they were much more relaxed in the therapeutic garden than in any other environments.  

Incorporating nature into landscapes

Designing healthier and more pleasant landscapes in the cities, such as those found in Singapore can lead to wakeful relaxation and mindfulness. The CLM, a psychometric tool developed by NeuroLandscape scientists can be used “to measure and define the subjectivity in landscape aesthetics” such as landforms, vegetation, color and light, character of peace and silence. 

Results from the study of NeuroLandscapes show that the higher the CLM scores the higher the alpha activity is, which translates to wakeful relaxation and theta activity, which means mindfulness.

Using the CLM scores, urban green landscapes can be designed using components that provide specific benefits.  For instance, designing for healthy brain activities can focus on landscape layers and archetypal elements, while designing for public appreciation can emphasise peace and silence components. 

“These recommendations put forward by the study incorporate landscape features in the green spaces to achieve specific mental health and well-being targets,” said Olszewska-Guizzo. She also pointed out that more research is needed to “assess the long term exposure effects of different landscapes and to extrapolate the results on various populations.” 

Parks as Prescriptions

Green spaces and nature in the cities contribute not only to mental well-being, but with the physical as well. Research studies shared by Dr. Nicholas Alexander Petrunoff, Assistant Professor from the Saw Swee Hock School of Public Health, National University of Singapore suggest that green spaces such as parks help promote physical activity and “help keep people active, healthy, and well.”

“Physical inactivity is also a global pandemic since it’s a leading risk factor for morbidity and mortality globally,” Petrunoff said. He called physical activity a “wonder drug” because it reduces the risks of over 20 chronic health conditions including diabetes, cardiovascular diseases, depression, and many cancers. 

One of the projects of the National University of Singapore, the Parks and Health Project, demonstrated the negative correlation of the time spent in the park with the lower Body Mass Index and the risks of cardiovascular diseases. 

Meanwhile, the Park Prescription Intervention project was designed in collaboration with healthcare providers and community partners to utilise parks, trails, and open space for improving individual and community health. The study showed that the participants felt motivated to exercise and described being empowered to continue physical activities and group exercises. Non-regular attendees of group exercises, however, preferred to have unstructured activities which they could do in their own time.

Petronuff emphasised that parks and green spaces are important for both human and planetary health. “We need to redesign back into our urban lives links with nature to avoid developing chronic diseases for much of the population,” he said, noting that development plans of the governments should include improving access to parks and making cities more sustainable. 

Nature as therapy

Ms. Angelia Sia, deputy director of Research at the Centre for Urban Greenery and Ecology, NParks shared the results of two studies on park prescription, effects of landscapes on brain activity, and therapeutic horticulture. 

The first study showed that nature-related activities such as nature walks and gardening resulted in the improvement in the psychological status, biological markers, and immune cell composition of the senior participants. 

In the second study, a 24-week programme for the elderly with a range of cognitive and physical status showed a significant reduction in anxiety and improvement in cognitive functioning and reported more positive emotions after each session. 

 According to Ms. Sia, these research findings have since been translated into actionable insights, lending further science-based evidence for policymakers to support greening initiatives in the city.

“To bring the benefits of therapeutic horticulture closer to more people,  NParks is planning for a network of therapeutic gardens across Singapore,” said Sia, adding that they have already implemented six of these therapeutic gardens. Guidelines to inform the design of therapeutic gardens have also been published to enable external agencies to implement restorative landscapes in their premises. 

Meanwhile, Mr. Tham Xin Kai, Design Director of Hortian Consultancy and Co-founder of Hortherapeutics shared how dementia patients from a nursing home in Singapore benefited from a well-designed therapeutic garden. By using a multi-sensory approach such as planting fragrant plants and flowers, memories can be triggered by the smell while wind chimes can stimulate their hearing. Plants with different colors and textures are also abundant in the therapeutic garden so that patients can touch and appreciate them. 

Urban horticulture and empowerment 

 The movement restrictions during the worse periods of the COVID-19 pandemic not only limited the peoples’ interaction with nature. The temporary standstill of the local and national economy caused the loss of livelihoods and income. 

Improving job competencies and increasing employability are among the benefits of urban horticulture, according to Ms. Tham Siang Yu, Therapeutic Horticulture Practitioner and Founder of By Wind and Wave. She highlighted the three types of therapeutic horticulture programme models: vocational (providing employment opportunities), therapeutic, and social (importance of community integration and promoting social interaction) that can benefit specific segments of society. For instance, the horticulture vocational programme among young adults with autism in Singapore, which Ms. Tham led, focused on improving the students’ attention span and ability to follow a work schedule.  Another example cited is the Rikers Island Prison Program in New York, where inmates who participated in the therapeutic horticulture program can join a team that designs and tends the gardens in the city once they are released.   

 “Apart from learning gardening and horticultural skills, the participants learn valuable life skills such as responsibility and time management and these empower them to turn their lives around,” Ms. Tham said.

Protecting cities from climate change

Well-planned and mindfully-developed urban areas where biodiversity thrives are essential, especially as the ASEAN region strives to recover from the public health crisis, and re-energise its trajectory. Not only will it help alleviate moods and other mental conditions, biodiversity in cities provide protection against the climate crisis as well.

“Despite the threat of a new COVID variant looming before us, the ASEAN region strides towards COVID-19 recovery and slowly eases back to normal,” ACB Executive Director Theresa Mundita Lim said. “We feel relieved and rejuvenated to be given the opportunity to appreciate the open spaces around us that remind us of nature’s ability to heal – providing not only physical, but also mental health benefits as well, contributing to the overall well-being of an individual, or even a community.” 

 On 29 October 2021, the international community celebrated World Cities Day highlighting the crucial role of nurturing biodiversity in urban areas as a mechanism to build climate resilience. With the theme Adapting Cities for Climate Resilience, the celebration underscores the important role of nature-based solutions to reduce climate-related risks for urban populations.

Coincidingly, the updated Handbook on Singapore Index on Cities’ Biodiversity, which provides practical guidance on how to enhance greenery in densely populated areas, has recently been released. The Index is a self-assessment tool that cities around the world can use to ‘benchmark and monitor’ their efforts to conserve biodiversity in urban areas through various indicators.

Dr. Lim noted that apart from health benefits, healthy ecosystems provide protection and buffer against climate change manifestations such as super typhoons, flooding, storm surge, and help mitigate the long-term impacts of drought, sea-level rise, and saltwater intrusion. 

In the cities, green spaces with abundant trees and other vegetation help regulate water and air quality, keep the area cool, and provide shade in addition to being a source of food as well as relaxation to the urban populations.

 “We look towards nature for healing and protection. Conserving and integrating biodiversity – from our homes to our cities, and to our region – can advance a safer, better, and more resilient future,” Lim said.

Ms.  Wendy Yap, Director of International Biodiversity Conservation from NParks said the virtual ASEAN workshop on Therapeutic Horticulture is the first of the two-part regional workshop, which aims to explore the health benefits of urban biodiversity and greenery. Singapore will be hosting the second part of the workshop next year. Ms. Yap further expressed her hopes that the programmes shared and discussed in the virtual workshop can be considered by other cities and countries. #