Rewilding and Recolonizing Efforts within Singapore’s Cities
By Janaya Jesperson
Keywords: Rewilding, Conservation, City Planning, Environmental Management
Summary
Between 2009 and 2012, Bishan-Ang Mo Kio Park underwent the rewilding of the portion of the Kallang River that ran through the park. After extensive planning, the previous concrete canal was replaced with a rewilded riparian environment that provided the surrounding area with natural water treatment and flood management. The rewilding of the river has made a safer space for locals and has encouraged a thirty percent increase in biodiversity to the area, with the return of endangered species such as the smooth coated otter. Additionally, the project resulted in a significant increase in visitors to the park and increased use from local residents. Currently the project is used as a framework for city planners worldwide to rewild urban areas due to the success it has generated for biodiversity, visitor engagement, and increased quality of life for locals.
However, Bishan-Ang Mo Kio park is not without its faults or concerns. The park is currently a designed ecosystem, rather than a truly wild space, due to requirements for extensive management for its grassy and manicured spaces, along with continuous monitoring and management to combat challenges associated with urban rewilding. The park is still in need of improvements to generate a hands off and wild space, but has a promising foundation to build off of and learn from for future projects. |
Ecological Geneology
Singapore is a small city-state with 5.5 million inhabitants but is only 699.4 square kilometers, making it the smallest nation in Southeast Asia (Geh & Sharp, 2008). Being located near the equator places Singapore in one of the most biodiverse regions on earth (Geh & Sharp, 2008). Pre-colonization, Singapore had lush tropical rainforests with a diverse range of flora and fauna; however, soon after the British East India Company landed in 1819, there was a drastic change to these landscapes (Geh & Sharp, 2008). Plantations, agriculture, and infrastructure changed the small nation, and by 1883 ninety-three percent of its forests had been destroyed (Chan et al., 2010; Corlett, 1992) with an extinction rate estimated at thirty-seven percent (Chisholm et al., 2023). During this period, a significant portion of the population lived in squalid conditions as they witnessed and were forced to participate in the major deforestation enacted by colonizers (Geh & Sharp, 2008).
Post-colonization and after further devastation caused by WWII, Singapore gained their independence from British colonizers and became a city-state in 1965 (Geh & Sharp, 2008). In 1967 Singapore officially launched their Garden City program, to acknowledge and embrace the benefits of incorporating green spaces within their urban spaces (Chan et al., 2010). This resulted in Nature Reserves being established along with community parks built throughout the country (Corlett, 2022). By reallocating their priorities to incorporate green and blue spaces within urban areas, Singapore regained approximately fifty-six percent of vegetation coverage (Corlett, 2022). Additionally, reports suggest a significant increase in quality of life with consistently high rankings in numerous livability surveys globally (Khoo, 2019). The erection of Bishan-Ang Kio Park, originally called Bishan Park, occurred in 1988 (Khoo, 2019). The goal of the park was to incorporate green and blue spaces into urban environments and to act as a green buffer in between the densely populated Ang Mo Kio and Bishan (Koh et al., 2022). Designed by landscape architects and encompassing 42 hectares, the park incorporated existing natural forest and also featured a frangipani garden, a palm court lined with palm trees and a lake with a floating amphitheater (Koh et al., 2022). The architects included amenities including trails, sports fields, courts, and playgrounds, to encourage residents surrounding the park to utilize the space (Lim & Xenarios, 2021). In 1992, the park was the first in Singapore to be made accessible through the park connector network, allowing users to jog or cycle from one park to another seamlessly along drainage canals (Lim & Xenarios, 2021). At the time of its creation, Bishan-Ang Kio Park, the Kallang River ran through the park and was directed through a 2.7 kilometer concrete canal that hindered the park’s goal of connectivity with its unsightly appearance and limited public access on either side of the canal (Lim & Xenarios, 2021). For people’s safety the canal was blocked off from residents by fences and other barriers; however these barriers also made the area hard to exit and there were reports of children being trapped in the canals while water levels were rising (Corlett, 2022). The concrete canal, while not aesthetically pleasing, potentially dangerous, and obstructive to the main goals of the park, served an important function for flood management for the surrounding area (Khoo, 2019). The original canal in Bishan-Ang Mo Kio Park began to experience signs of decay as the concrete weathered and crumbled (Khoo, 2019). It became clear that it was in need of significant repairs. Therefore, the park was slated for redesign as part of Singapore’s ABC Waters Programme (Active, Beautiful, and Clean Waters). Rather than rebuild the concrete waterway, agencies involved, including Singapore’s National Park Service, opted to rewild and re-naturalize the river (Khoo, 2019). The new river design aimed to integrate functionality with improving human interaction with the park by creating a more accessible and less dangerous storm water management system (Lim & Xenarios, 2021). Furthermore, it was designed to mimic the natural hydrology historically present by integrating aquatic and terrestrial ecosystems (Koh et al., 2022). Additionally, by incorporating an understanding of biophysical processes into their management plan, the redesign would be more equipped to handle intense periods of flooding during monsoon season compared to the previous concrete system (Koh et al., 2022). |
Figure 1:Water catchments and connections of parks and urban spaces in Singapore
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Present tense
The rewilding of Bishan-Ang Mo Kio Park’s section of the Kallang River underwent construction in 2009 and was completed in 2012 (Khoo, 2019). After its completion it quickly received international attention and was adopted as a framework for city planners worldwide to successfully rewild urban areas (Khoo, 2019). The project required meticulous planning for the engineering process of the river to ensure erosion wouldn’t affect the banks during floods (Lim & Xenarios, 2021). The engineering team used a combination of civil engineering and natural plants and materials to generate soil stabilization that relied heavily on root systems (Khoo, 2019). To ensure their methods would work they created a sixty meter test bed from a diversion in the river (Khoo, 2019). For eleven months, this testbed was introduced to recolonized native plants, until they were left with an area that had stable slopes and a rewilded riparian environment (Khoo, 2019).
The rewilded ecosystem has additional benefits for the area as the vegetation helps treat and purify the water naturally (Lim & Xenarios, 2021). The engineering teams achieved this by selecting plants such as equisetum hyemale, cyperus alternifolius, portulaca orleracea, and cyperus haspan, that could clean the water of phosphorus, nitrogen, and copper (Lim & Xenarios, 2021). The park then redirects the now purified runoff water into its pond system, back into the river, and also to the water playground located in the park (Lim & Xenarios, 2021). With the new enlarged river ecosystem the park Bishan-Ang Mo Kio Park underwent a thirty percent increase in biodiversity following the project, with over sixty species of wildflowers, more than fifty bird species, and over twenty species of dragonflies, some of the now present species are extremely rare to find outside of nature reserves (Koh et al., 2022). The park has also seen an increase in larger animals that have been absent in the area (Khoo, 2019), including some endangered species, such as, a family of smooth coated otters, affectionately dubbed the Bishan 5, that have established themselves in the park (Koh et al., 2022). The the project has increased its use among community members and visitors from approximately three million visitors to six million visitors per year (Koh et al., 2022). The park aims to integrate people with the flora and fauna of Singapore, rather than keep them on either side of a fence (Khoo, 2019). Within the park there are amenities that aim to foster a holistic living environment amidst the vegetation, by incorporating businesses to increase park usage, such as a spa and various restaurants (Lim & Xenarios, 2021). As more species establish themselves in the park, there also comes some increased danger for visitors as there is an increase in interactions with wildlife, especially due to the larger fauna such as monitor lizards and the smooth coated otter, returning to the area (Hwang & Jonathan Yue, 2019; Khoo, 2019). To help address this concern, the park also aims to help foster better relationships and respect for wild places by incorporating educational programs throughout the park (Koh et al., 2022). These programs are designed to instill a sense of personal ownership and responsibility for the park among all age groups to ensure the place and all inhabitants from people, to animals and plants are respected and valued (Khoo, 2019). |
Figure 2: Before and after the completion of the rewilding of Kallang River.
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Future Trajectory
The rewilding and reintroduction of species in Bishan-Ang Mo Kio Park still has plenty of room for improvement. The park still features many grassy areas that could be revegetated by native species. The park still requires management to ensure upkeep of its more manicured areas and to ensure the river retains its capacity for handling flood waters. This makes portions of the park a designed ecosystem rather than a truly rewilded area. Consequently, as rewilding and the return of species continues to take place in the park, careful management will need to persist in order to combat the challenges associated with urban rewilding (Ho et al., 2023), which include managing the spread of invasive species along roadways and other fragmented areas of the park, managing the spread of diseases from returned species, and ensuring there remains to be a positive relationship between people and rewilded areas (Hwang & Jain, 2021).
However, the trajectory that Bishan Mo Kio Park is on, much like the rest of Singapore, is incredibly promising for fostering a future that fits into Singapore’s goal of becoming a City in Nature (Khoo, 2019). The continued connection of green and blue areas throughout Singapore and the drive from the government and public alike to foster ecologically managed urban environments that incorporate wild spaces, should continue to inspire other nations and cities to incorporate similar value in their urban development to see a greener and wilder earth. |
References
Geh, M., & Sharp, I. (2008). Singapore's natural environment, past, present and future: A construct of national identity and land use imperatives. In Spatial planning for a sustainable Singapore (pp. 183-204). Dordrecht: Springer Netherlands.
Chan, L., Davison, G., & Chia, C. (2010). Biodiversity Conservation in Singapore. CITYGREEN, 01(01), 60. https://doi.org/10.3850/S2382581210010112
Chisholm, R. A., Kristensen, N. P., Rheindt, F. E., Chong, K. Y., Ascher, J. S., Lim, K. K. P., Ng, P. K. L., Yeo, D. C. J., Meier, R., Tan, H. H., Giam, X., Yeoh, Y. S., Seah, W. W., Berman, L. M., Tan, H. Z., Sadanandan, K. R., Theng, M., Jusoh, W. F. A., Jain, A., … Sin, Y. C. K. (2023). Two centuries of biodiversity discovery and loss in Singapore. Proceedings of the National Academy of Sciences, 120(51), e2309034120. https://doi.org/10.1073/pnas.2309034120
Corlett, R. T. (1992). The Ecological Transformation of Singapore, 1819-1990. Journal of Biogeography, 19(4), 411. https://doi.org/10.2307/2845569
Corlett, R. T. (2022). Ten lessons from Singapore for the conservation of tropical biodiversity. Nature in Singapore, Supplement 1, 1013. https://doi.org/10.26107/NIS-2022-0068
Ho, C., Dehaudt, B., Lee, B. P. Y. H., Tan, H. Y. R., & Luskin, M. S. (2023). Recolonizing native wildlife facilitates exotic plant invasion into Singapore’s rain forests. Biotropica, 55(5), 1033–1044. https://doi.org/10.1111/btp.13251
Hwang, Y. H., & Jain, A. (2021). Landscape design approaches to enhance human–wildlife interactions in a compact tropical city. Journal of Urban Ecology, 7(1), juab007. https://doi.org/10.1093/jue/juab007
Hwang, Y. H., & Jonathan Yue, Z. E. (2019). Intended wildness: Utilizing spontaneous growth for biodiverse green spaces in a tropical city. Journal of Landscape Architecture, 14(1), 54–63. https://doi.org/10.1080/18626033.2019.1623548
Khoo, T. C. (2019). Building a City in Nature. In T. Schröpfer & S. Menz, Dense and Green Building Typologies (pp. 13–19). Springer Singapore. https://doi.org/10.1007/978-981-13-0713-3_4
Koh, Y. F., Loc, H. H., & Park, E. (2022). Towards a “City in Nature”: Evaluating the Cultural Ecosystem Services Approach Using Online Public Participation GIS to Support Urban Green Space Management. Sustainability, 14(3), 1499. https://doi.org/10.3390/su14031499
Lim, M., & Xenarios, S. (2021). Economic assessment of urban space and blue-green infrastructure in Singapore. Journal of Urban Ecology, 7(1), juab020. https://doi.org/10.1093/jue/juab020
Chan, L., Davison, G., & Chia, C. (2010). Biodiversity Conservation in Singapore. CITYGREEN, 01(01), 60. https://doi.org/10.3850/S2382581210010112
Chisholm, R. A., Kristensen, N. P., Rheindt, F. E., Chong, K. Y., Ascher, J. S., Lim, K. K. P., Ng, P. K. L., Yeo, D. C. J., Meier, R., Tan, H. H., Giam, X., Yeoh, Y. S., Seah, W. W., Berman, L. M., Tan, H. Z., Sadanandan, K. R., Theng, M., Jusoh, W. F. A., Jain, A., … Sin, Y. C. K. (2023). Two centuries of biodiversity discovery and loss in Singapore. Proceedings of the National Academy of Sciences, 120(51), e2309034120. https://doi.org/10.1073/pnas.2309034120
Corlett, R. T. (1992). The Ecological Transformation of Singapore, 1819-1990. Journal of Biogeography, 19(4), 411. https://doi.org/10.2307/2845569
Corlett, R. T. (2022). Ten lessons from Singapore for the conservation of tropical biodiversity. Nature in Singapore, Supplement 1, 1013. https://doi.org/10.26107/NIS-2022-0068
Ho, C., Dehaudt, B., Lee, B. P. Y. H., Tan, H. Y. R., & Luskin, M. S. (2023). Recolonizing native wildlife facilitates exotic plant invasion into Singapore’s rain forests. Biotropica, 55(5), 1033–1044. https://doi.org/10.1111/btp.13251
Hwang, Y. H., & Jain, A. (2021). Landscape design approaches to enhance human–wildlife interactions in a compact tropical city. Journal of Urban Ecology, 7(1), juab007. https://doi.org/10.1093/jue/juab007
Hwang, Y. H., & Jonathan Yue, Z. E. (2019). Intended wildness: Utilizing spontaneous growth for biodiverse green spaces in a tropical city. Journal of Landscape Architecture, 14(1), 54–63. https://doi.org/10.1080/18626033.2019.1623548
Khoo, T. C. (2019). Building a City in Nature. In T. Schröpfer & S. Menz, Dense and Green Building Typologies (pp. 13–19). Springer Singapore. https://doi.org/10.1007/978-981-13-0713-3_4
Koh, Y. F., Loc, H. H., & Park, E. (2022). Towards a “City in Nature”: Evaluating the Cultural Ecosystem Services Approach Using Online Public Participation GIS to Support Urban Green Space Management. Sustainability, 14(3), 1499. https://doi.org/10.3390/su14031499
Lim, M., & Xenarios, S. (2021). Economic assessment of urban space and blue-green infrastructure in Singapore. Journal of Urban Ecology, 7(1), juab020. https://doi.org/10.1093/jue/juab020