Eleanor Scott tells us all about our second love, the mighty tree, and the importance of green space in our cities.
Trees are one of nature’s most resilient creations and they play a vital role in making our cities liveable. From public parks to residential gardens to street trees, every aspect of a city’s vegetation, no matter how small, makes up a part of its larger ‘urban forest’. But as urban densification increases, buildings are replacing more and more trees, and though that loss may not be immediately felt, it is significant.
Green environments dramatically improve the quality of life of all urban dwellers. They reduce energy use and carbon dioxide emissions, cool the air, create a home for birds and insects, and generally result in positive mental and physical health benefits. People who live near urban vegetation are less prone to violence and report reduced anxiety and stress levels – it can even increase social engagement between neighbours.
“Green space should be a priority for all urban centres, but it also needs to be evenly distributed across the population.”
With this in mind, green space should be a priority for all urban centres, but it also needs to be evenly distributed across the population. It’s widely accepted that wealthy neighbourhoods are greener and wealthier people tend to be healthier, but by promoting good health urban vegetation also has the potential to reduce the rich-poor wellbeing gap. In 2008 a study by Rich Mitchell, a public health professor at the University of Glasgow, determined that people exposed to greener environments also “have the lowest levels of health inequality related to low income”.
“The New York City Department of Parks & Recreation measured the economic benefit of their trees to be over $100m a year.”
However, up until recently city policies have often reflected a negative attitude toward urban forests. Trees were seen, at worst, as an obstacle of urban densification and, at best, as an expensive decoration. But compelling evidence of both the ecological and economic benefits they provide is slowing changing the conversation. Most notably, the New York City Department of Parks & Recreation measured the economic benefit of their trees to be over $100m a year due to stormwater interception, air pollutant removal, energy conservation and carbon dioxide reduction.
As a result, many governments, from local to federal, are already implementing strategies to increase tree coverage. But it will require new approaches to development, urban planning and conservation to really make a difference. If green spaces aren’t designed well they can reduce the area available for sports activities, decrease fruit and vegetable production, obstruct solar panels, and create unsuitable habitats for other kinds of plants and animals. Collaboration between all disciplines and sectors, from governments to academics to practitioners, is vital to the continued creation and preservation of useful urban vegetation.
Over 50% of Mexico City, the Western Hemisphere’s most populous megacity, is also covered in legally appointed conservation land. Much of this is due to the Water Forest, a tranquil enclave that spans over 250,000 hectares of land and provides up to 75% of Mexico City’s water supply. However, the existence of an official designation hasn’t protected the conservation area from rapid urbanisation and illegal logging. Having lost 35% of forest cover in the last 40 years, the government and environmental groups have begun working together on restoration projects to ensure a sustainable future. In particular, Mexico City’s ‘Green Plan’ has seen their carbon dioxide emissions lower by 80,000 tons annually, while conservation organisation Monitoreo Biológico de Milpa Alta has successfully secured several streams of funding to counteract the deforestation of native grasslands.
“Our understanding of environmental importance is shaped through childhood experience. Growing up without a connection to nature ultimately leads each generation of policymakers to place less and less value in conservation.”
Education is another factor. Our understanding of environmental importance is shaped through childhood experience. Growing up without a connection to nature ultimately leads each generation of policymakers to place less and less value in conservation. To combat this, projects by organisations such as the Slovenian Forestry Institute are working to promote appreciation of forests and their role in people’s health and well-being through hands-on experiences. Initiatives like the forest “classroom” at Tivoli City Park help raise awareness while highlighting the differences between, and benefits of, urban vegetation and natural forests.
As urban centres become increasingly dense, green space must be prioritised to ensure a high standard of living for all inhabitants. Generating a wide array of socioeconomic and environmental benefits, it’s clear that cities need thoughtfully designed urban forests that engage the communities around them, are equitably distributed, and diligently managed to safeguard the urban landscape for generations to come.