Once something is gone, it will never come back again. With all the urban development around Singapore, we lost much of our beloved natural environment and its biodiversity. By 1990, almost 90 percent of Singapore’s original forests were gone. However, not all hope is lost as the Singapore Botanic Gardens (SBG) has been actively restoring the “lost” biodiversity in our natural environment.

Figure 1: View of the Keppel Discovery Wetland (Source: Shi Zheng Yan, 12 February 2022)

Together with Professor Gretchen Coffman, my Applied Biogeography class field trip to the Singapore Botanic Gardens (SBG) took me to the Learning Forest and the Keppel Discovery Wetland. The Learning Forest is now home to restored lowland rainforest and freshwater wetland forest. It boasts up to 700 species of plants, including 25 species of our beloved orchids. The aim of the restoration is to focus on adding endangered and rare individual plant species and biodiversity to entire ecosystems in a beautiful biophilic landscape (Figure 1.).

Figure 2: The canopy of a Tembusu Tree (Cyrtophyluum fragrans), which can grow up to 30m tall (Source: Arthur Seng, 6 February 2022)

SBG has reintroduced various tall, native dipterocarps species such as Yellow Meranti (Shorea faguetiana) and transplanted them into the forest to accompany the existing old Tembusu (Cyrtophyllum fragrans) (Figure 2) and Jambu Laut (Syzygium grande). This mimics and recreates the structure of the natural tropical lowland rainforest from the past. Stumps of non-native rubber trees (Castilla elastica) can be found within the lowland secondary rainforest as they were gradually cut down. They were not part of the original ecosystem as they were propagated from past surrounding rubber plantations.

The Keppel Discovery Wetland is also a testament to SBGs restoration efforts. The restored forested freshwater wetland provides an important ecosystem for a rich diversity of freshwater species to thrive in. Wetland orchids have benefited from the restored wetland ecosystem under the SBG’s Orchid Conservation Programme. Through ex-situ conservation methods, once native orchid species such as the Deer Antlered Phalaenopsis (Phalaenopsis cornucervi) and Finlayson’s Cymbidium (Cymbidium inlaysonianum) are sourced overseas and reintroduced into the wetland ecosystem.

Figure 3: Tiger Orchids Island (Grammatophyllum speciosum) found in Keppel Discovery Wetland, which is around 160 years old (Source: Hansel Li, 12 February 2022)

The wetland ecosystem also enables Tiger Orchids (Grammatophyllum speciosum) to thrive and reproduce through rhizomes on one of the islands, with the cluster of stems curving inwards to support each other. As a result, the ecosystem helps cultivated one of the world’s largest Tiger Orchids (Figure 3) in Singapore.

Stepping into the Learning Forest and Keppel Discovery Wetlands gave me the feeling of travelling back in time. It was a privilege to be able to witness and learn about Singapore’s native species and its history once again in the present. However, we cannot take all these for granted. The worsening presence of invasive species such as hydrilla in the wetlands has threatened to undo everything SBG has done to conserve our natural environment. Hence, I believed that it is important to educate the public about such issues, to inspire people to contribute in their own way to the conservation of rainforests. These rainforests are a living, breathing, part of Singapore’s past, present and future.

Written by: Shi Zheng Yan