Te Herenga Waka—Victoria University of Wellington PhD student Maggie MacKinnon’s research investigates the role buildings could play in enhancing urban green infrastructure.
Rapid and increasing urbanisation results in habitat loss and degradation and is a primary threat to global biodiversity. The loss of biodiversity negatively impacts ecosystems and the resources and services they provide. This exacerbates climate change and has negative implications for human well-being.
Protecting and restoring large areas of native habitat outside of urban environments is critical for species conservation, but could we provide more habitat for biodiversity in our cities?
While cities may have limited ground-level space for vegetated habitats, Maggie argues that buildings could provide a solution. Though most buildings are detrimental to ecosystems, regenerative architecture strategies, such as green roofs, could enable them to provide food and shelter for urban biodiversity, purify the air, moderate temperature, absorb noise, and help reduce disturbances.
To begin researching how buildings could provide habitat for native species, Maggie looked at how to increase the quantity and connectivity of habitat in central Wellington using existing building roofs. Wellington was selected as the research site because of the urban densification, population growth, and climate change challenges it is facing.
Using habitat quantity and connectivity targets set by previous New Zealand researchers, Maggie tested the performance of the existing green space network in Wellington’s Te Aro neighbourhood to determine where buildings could supplement it.
Her initial findings revealed insufficient green space in Te Aro to meet the minimum habitat targets to stop native species decline. The small sizes of the majority of the green spaces and their uneven distribution throughout the neighbourhood resulted in several areas isolated from habitat. A lack of connectivity between green spaces can make it challenging for species, such as birds, to disperse across cities.
A spatial analysis of the roof area in Te Aro revealed a surplus of roofs that could be converted to green roofs. The strategic utilisation of less than 10% of Te Aro’s roofs could increase the amount of vegetated habitat in the neighbourhood and improve habitat connectivity across the central business district.
Implementing regenerative design strategies, such as green roofs, could also help improve building performance and help Wellington mitigate and adapt to climate change, which will be crucial for the current and future well-being of its urban residents.
Buildings and cities are not often included in urban green infrastructure plans or biodiversity conservation strategies, but they could play more of an important role. Maggie’s research will draw upon the expertise of ecologists, conservation biologists, and botanists to determine how buildings can provide habitat for native plants and birds in Wellington. Advancing research in this area is crucial for urban biodiversity conservation, ecosystem services, climate change mitigation, and human well-being in cities.
Maggie MacKinnon is a PhD candidate in the Wellington Faculty of Architecture and Design Innovation under the supervision of Dr. Maibritt Pedersen Zari and Professor Daniel K. Brown.
Contact Maggie to learn more about her research at maggie.mackinnon@vuw.ac.nz.
