I’m happy with trees, but we also need biodiversity in our cities | 360info

Increasing the amount of nature in our cities can bring many benefits, as long as it is done with biodiversity in mind.

A tree-lined city boulevard is often a welcome sight for the weary pedestrian on a warm summer day.

But such streets, even though cooler than their non-canopy counterparts, may provide little benefit to biodiversity or native wildlife if they are filled with a single species of non-native canopy tree.

This is because many of the benefits of nature in cities are related to biodiversity – and not just greenery.

For example, native vegetation in parks has been linked to better gut health in park visitors.

Nature in cities can play a major role in addressing many of the unprecedented livability challenges, including adapting to extreme weather and helping with a mental wellness crisis.

Cities with nature improve our mental and physical health, improve the cognitive development of our children, purify our air and water and reduce the effects of storms and heat waves.

Cities also have an important role to play in tackling the biodiversity extinction crisis, with a disproportionate number of threatened species living in or on the edges of our cities.

Rather than leaving it to chance, intentional strategies that bring back and care for native plants and animals in our cities would benefit both nature and people.

To this end, biodiversity-sensitive urban design is now a recommended approach for urban developers in several Australian states and has been legislated in South Australia, which has also recently launched an urban greening strategy for metropolitan Adelaide.

This approach is in line with Goal 12 of the Kunming-Montreal Global Biodiversity Framework, ratified by 196 countries, which focuses on the importance of finding space for nature within built landscapes.

Biodiversity-sensitive urban design requires developers, architects and urban planners to consider the history of a place, its current condition and the potential to restore or bring back nature – summarized as a place’s past, present and potential.

For example, a site may currently be devoid of trees (present), but may have supported a threatened ecosystem in recent history (past) and could potentially be reconnected with nearby remnant vegetation, giving wildlife the opportunity to return times (potential).

Setting clear objectives is the next step, for example bringing back a locally extinct species, or making a local river swimmable again.

Once objectives are identified, designs can be developed to provide resources to support target species, including vegetation, water and nesting habitat. Designs can limit threats, for example through nature-friendly lighting, bird-sensitive glass, underpasses or viaducts; and creating ecological connectivity so that wildlife can move across an area.

An important additional step is to design ‘cues to care’: encouraging people to interact positively with nature in cities and to be active managers of biodiversity.

There is great potential to use the urban renaturation agenda to create a sense of place and identity in cities, rather than accepting the homogenization of urban areas around the world.

Furthermore, highlighting biocultural diversity in urban renaturation – nature that emphasizes traditional uses of plants or the cultural significance of wildlife – can increase knowledge of and respect for indigenous or traditional land management and culture, including medicinal plants and cultural stories about wild animals.

For example, in Surabaya, Indonesia, urban greening using traditional food and medicine plants can also provide a source of income for residents.

Another example is a nature playground in Melbourne, Australia, where the seven Wurundjeri seasons are celebrated.

The motivations for designing for nature in cities have never been more compelling.

With the global urban population expected to increase by 2.5 billion people over the next thirty years, urbanization is one of the defining transformations of the 21st century.

Biodiversity cities have the potential to turn around the fortunes of the many endangered species that depend on cities and provide a remarkable range of benefits that will prove crucial to the viability and future habitability of cities.

Sarah Bekessy, RMIT University

Professor Sarah Bekessy
leads the Interdisciplinary Conservation Science Research Group (ICON Science)
at RMIT University. Chief Council Member of the Biodiversity Council, Board Member of Bush Heritage Australia, Member of WWF’s Eminent Scientists Group and Member of the Advisory Group for Wood for Good. More by Sarah Bekessy, RMIT University