To help you keep abreast of the latest research and development in urban nature, we collate and summarise leading journal articles. This month, topics include (1) urban waterbodies and bird species diversity, (2) the role of street trees in biodiversity efforts, (3) emerging economies and inequity in urban forest distribution, (4) microclimates at urban green roofs, and lastly (5) the relation between urban nature experiences and sustainable consumption. Enjoy!
1. The role of urban waterbodies in maintaining bird species diversity within built area of Beijing (geographical scope: Beijing, China)
Xie, S., Marzluff, J. M., Su, Y., Wang, Y., Meng, N., Wu, T., … & Ouyang, Z. (2022). The role of urban waterbodies in maintaining bird species diversity within built area of Beijing. Science of The Total Environment, 806, 150430.
- This study shows that waterbodies can serve as bird diversity ‘hotspots’ in urban landscapes through the following three findings: (1) parks with waterbodies attract a higher number of bird species during the breeding and wintering season (if the waterbody is not frozen), (2) waterbodies inside and outside parks contribute to forest bird species richness and (3) in parks without waterbodies, the number of forest bird species significantly increases with the number of waterbodies within the neighbourhood.
- In conclusion, urban forest birds prefer habitats near waterbody patches. Besides waterbodies in parks, blue patches in neighbouring areas contribute to species diversity in highly urbanized areas. Creating and maintaining urban waterbodies in or near parks can significantly increase biodiversity for future urban landscapes.
2. Are street trees friendly to biodiversity? (geographical scope: 59 Chinese cities)
Liu, J., & Slik, F. (2022). Are street trees friendly to biodiversity? Landscape and Urban Planning, 218, 104304.
- This article sets out to understand how street trees, besides benefiting human well-being, can contribute to wildlife conservation. The authors find that most cities are dominated by only a few species of trees, of which a large proportion is non-native nor attractive to wildlife. Biodiversity-friendly cities should ensure a large number of tree species that support multiple ecosystems functions.
- Urban planners should consider biodiversity conservation as a core value by (1) planting more native trees as foraging resources for native animals (2) identifying a more diverse set of tree species capable of attracting and supporting wildlife. Furthermore, awareness of biodiversity-friendly tree planting is crucial for future urban development.
3. The inequity of distribution of urban forest and ecosystem services in Cali, Colombia (geographical scope, Cali, Colombia)
Shiraishi, K. (2021). The inequity of distribution of urban forest and ecosystem services in Cali, Colombia. Urban Forestry & Urban Greening, 127446.
- This paper explores the uneven distribution of urban forests in emerging countries – characterized by irregular and unregulated land-use patterns, social inequities and socio-economic instability. The results demonstrate that lower-income communities have lower tree canopy cover, fewer parks and smaller park areas than higher-income communities. The lack of access to greenery also means that the benefits of urban forests are inequitably distributed.
- The paper identifies a set of causes for the unequal distribution in Cali: (1) low-income neighbourhoods are constructed with higher population and housing densities without proper planning strategies, (2) some of the low-income neighbourhoods are densely placed on a hillside, where fewer convenient places for urban greenery can be found, (3) low-income/middle-income neighbourhoods have fewer gardens compared to high-income communities, (4) there is a lack of awareness on urban forest values as well as knowledge on how to integrate these values into planning strategies.
- It is important that urban forests and ecosystems services are accounted for in city planning efforts to reduce inequity in emerging countries. There is a need for technology and information-sharing within and between countries to close the knowledge gap many developing countries have in research areas related to urban forests.
4. Urban green roofs to manage rooftop microclimates: A case study from Sydney, Australia (geographical scope Sidney, Australia)
Fleck, R., Gill, R. L., Saadeh, S., Pettit, T., Wooster, E., Torpy, F., & Irga, P. (2022). Urban green roofs to manage rooftop microclimates: A case study from Sydney, Australia. Building and Environment, 209, 108673.
- City planners are increasingly turning to nature-based solutions to deal with the urban heat island effect (NbS). One emerging urban NbS technology is the addition of green infrastructure to roofs and buildings. Green roofs are one of the most actionable NbS strategies as a significant portion of roofs in urban centres is suitable for green retrofitting. The vegetation of green roofs can reduce heat absorbed by the buildings through evapotranspiration and the reflection of solar radiation.
- This study investigates the potential and benefits of green roofs by comparing two identical buildings, of which one is equipped with a green roof. The study indicates a reduction in rooftop temperatures up to 20 °C when outside temperatures exceeded 40 °C and a cooling effect of shaded temperatures with 54%.
- In conclusion, green roofs have the ability to reduce building heat during summer and especially during severe heatwave conditions. These results highlight the potential of green roofs for energy savings and the much-needed mitigation of the urban heat island effect.
5. The role of urban nature experiences in sustainable consumption: a transboundary urban ecosystem service (geographical Scope: Singapore)
Jaung, W., Carrasco, L. R., Richards, D. R., Shaikh, S. F. E. A., & Tan, P. Y. (2022). The role of urban nature experiences in sustainable consumption: a transboundary urban ecosystem service. Environment, Development and Sustainability, 1-21.
- One of the widely recognized benefits of urban nature is its contribution to promoting environmental behaviour. This study aims to find if this type of behaviour has the potential to reduce individual consumption and therefore decrease the overall footprint of urban areas.
- The findings show that learning in urban nature positively affects biospheric values (values concerned with non-human species and nature such as species extinction) and the personal norms of the public. These values and norms promoted citizen support for sustainable consumption, such as support for certified timber products, organic products and an adverse to non-sustainable products.
- In conclusion, these results indicate that the benefits of urban nature transcend the city’s boundaries as urban nature can support ecological footprint reduction that influences surrounding areas. Urban nature can encourage sustainable consumption and promote pro-environmental behaviour.