Biodiversity conservation in Singapore
Volume 5 Number 2 - July 2008
Singapore is a small island city-state in one of the most biodiverse regions of the world. The land area of Singapore is about 697 sq km with about 10% of this, a result of land reclamation. With a population of 4.4 million, it is also one of the most densely populated cities in the world. The gross domestic product of over S$243 billion in 2007 (www.singstat.gov.sg) indicates robust economic activities. The combination of limited land, high population and significant industrial activities means that major planning efforts are constantly required to manage competing land use. Singapore has executed this adroitly. While material improvements and economic benefits have driven planning and decision making, biodiversity conservation has been given due importance.
The founding of modern Singapore in 1819 by the British, led to rapid colonization and population growth with extensive agricultural activities. The primeval rainforest that covered virtually all of the island was felled for cash crops that included gambir (Uncaria gambir) for the production of cutch (or catechu) used in tanning leather, pepper (Piper nigrum) and nutmeg (Myristica fragrans). Gambir was ecologically the most damaging, as a great deal of firewood, obtained by cutting more forest, was required to boil down the leaves. Land under rainforest cleared of vegetation loses its fertility very quickly. After a few years of cropping when both fertility and firewood were depleted, the farmers moved to new forest sites. By the 1880s only 7% of the original forest remained (Cantley, 1884). Current estimates indicate that 2,053 species of vascular plants were native to Singapore and some 1,454 species are still surviving (Tan et al, 2008).
The green spaces
Today the public green areas of Singapore are mostly under the management of the National Parks Board (NParks). These exceed 9,500 ha or about 13.6% of the total land area of Singapore (www.nparks.gov.sg). Of this, about 3,326 ha (almost 5%) are classified under Nature Reserves. These are the Bukit Timah Nature Reserve, a lowland dipterocarp forest, Central Catchement Nature Reserve, a lowland dipterocarp and freshwater swamp forest, Sungei Buloh Wetland Reserve, a mangrove habitat and Labrador Nature Reserve, a coastal hill forest. The last two were only gazetted in 2002, a significant achievement for conservation, in land-scarce Singapore. Other green areas forming a part of the 9,500 ha include parks, park connectors, playgrounds, and roadside gardens and vacant state lands.
Biodiversity and conservation
Singapore’s geographical location and its equable tropical climate support lush natural vegetation. Despite having lost more than 90% of its original forest cover, it is still home to a huge diversity of plants and animals. Apart from the over 1,400 species of native vascular plants still extant, 376 species of birds, 282 species of butterflies, 102 species of reptiles, 58 species of mammals and 27 species of amphibians, have been recorded. In the marine environment there are 200 species of hard corals, 111 species of reef fish and 11 species of sea grasses.
A far-reaching decision was made in 1963 that a green Singapore was a competitive factor in attracting foreign investment and would be a more attractive and comfortable home for its people. The first tree planting campaign the same year, symbolized this. In the years that followed a number of specific initiatives were put in place to ensure that adequate provisions would be made for urban greenery. Concept Plan Reviews are held periodically to better implement a Master Plan that guides the development of Singapore. A guiding principle of 0.8 ha of park space per 1,000 population was adopted, meaning that additional parkland would need to be provided as the population grows. Road codes were developed so that planting verges along major and minor roads were provided. Car parks must be designed with planting areas and structures like traffic flyovers and pedestrian overpasses clothed with climbers or creepers or screened by shrubs and trees.
Singapore is committed to conserving and ensuring the sustainability of its natural heritage. It is a signatory to the international Convention on Biological Diversity (CBD) resulting from the Rio Earth Summit in 1992. In the same year, the Singapore Green Plan was launched to provide a framework on biodiversity conservation. Nineteen nature areas (terrestrial and marine) were recommended. In 2003, the Singapore Green Plan 2012 was launched to better address conservation issues. In 2006, the National Biodiversity Reference Centre, under NParks, was established as a focal point for biodiversity conservation.
NParks has an active programme of biodiversity surveys and monitoring of its nature areas. In the last several years, 35 species of plants and animals new to Singapore have been discovered and seven species thought to be extinct have been rediscovered. These and other updates are highlighted in the second edition of the Singapore Red Data Book (Tan et al, 2008).
In the built up environment, NParks is committed to creating rich plant diversity in its parks, gardens and streetscapes. Trees and shrubs are planted intensively and extensively and NParks now manages about 1.3 million trees and many more million shrubs. It is estimated that the urban landscape now has been planted with over 3,000 taxa. Of the total, 70-75% are introduced species. It is likely that Singapore has the most biodiverse urban landscape, by far, of any city in the world. Satellite imagery showed that the estimated green cover of Singapore has increased significantly from 35.7% in June 1986 to 46.5% in August 2007 (See Table 1). To a large extent this increase is likely to be due to urban planting and the growth of the planted vegetation providing increasing ground cover.
Introduced species have so far not managed to invade and alter the composition and ecology of Singapore’s matured natural vegetation. This perhaps is an indication of the resilience and dynamism of the mature tropical rain forest. The most aggressive introduced species include: Acacia auriculiformis from the Australian region, Paraserianthes falcataria from east Malesia to the Solomons, Cecropia peltata from tropical America and Spathodea campanulata from Africa. These are able, though not very successfully, to invade open secondary forest areas as pioneers. The tropical American shrub, Clidemia hirta, penetrates old growth forest but only along more exposed trails. However, in time, primary lowland rain forest species introduced from the region, can be expected to invade matured native habitats.
In Singapore, a bold proposal is for a park connector network designed as green corridors that will connect parks, nature areas and open spaces to population centers. It is proposed that the network will cover the entire island, providing a matrix of vegetated links accessible only to pedestrians and cyclists. It is anticipated that the corridors will also facilitate bird life and bird movements and encourage other animal life. When completed in 2015, there would be a network of 300 km; currently, 100 km are opened for use.
Another two schemes initiated by NParks in 1991 are highlighted here. These are the Heritage Tree and Heritage Road Schemes. The former was designed to identify, recognize and conserve individual trees of historical, aesthetic, cultural, social or educational value. The public can participate in this scheme by nominating individual trees for consideration as a heritage tree. Currently 171 trees have been given this status. A plaque identifies each of them. The Heritage Road scheme, on the other hand, identifies and conserves specific roads with outstanding treescapes. Currently 5 roads totaling about 10 km have been gazetted as Heritage Roads
Public sentiments and life-style choices in Singapore are evolving to favour environment and conservation. A classic example is the way Chek Jawa; a tidal flat at the eastern tip of Pulau Ubin, an island to the northeast of Singapore was saved. This shallow shelf was identified for land reclamation in 1991, with work to begin in December 2001. However, over time nature enthusiasts discovered that this tidal habitat was exceptionally rich in marine life. In addition, the beach had both rocky and sandy components with a mangrove in the vicinity and a patch of coastal hill forest on the landward side. From mid 2001, lobbying to save the tidal flats intensified. The Government responded swiftly by calling for a study on the biodiversity and reclamation options. By January 2002, the Government decided that the proposed reclamation be deferred indefinitely. It has since funded the development of visitor facilities and conservation initiatives at Chek Jawa. This unique habitat has now become a popular visitor destination and an important outdoor educational resource.
The role of Singapore Botanic Gardens
In its early decades, the Singapore Botanic Gardens played important roles in recreation, research and forest conservation. From its founding in 1859, the Gardens staff began collecting and documenting plants. A journal, now The Gardens’ Bulletin Singapore, was started in 1881 to record the results of research in the Gardens. In 1883 when the first forest reserves were established in the Straits Settlements (the territories of Malacca, Penang and Singapore), they were placed under Director of the Gardens who was also the Conservator of Forests.
The Forest Department was to remain under the Gardens’ administration until 1895 when forest matters were officially transferred to the Land Office. By this time 35,776 ha had been designated as Forest Reserves in the Straits Settlements, a significant achievement in forest conservation. In 1939 the forest reserves in Singapore reverted back to the control of the Director of the Gardens.
The other major and continuing role of the Gardens was botanical exploration and documentation of the flora of the region, providing the baseline information for conservation decisions. Until the 1960s, nearly all significant publications on the flora of the Malay Peninsula resulted from the efforts of the Gardens’ staff.
It is interesting to note that in the 1880s, staff of the Gardens supervised tree planting in the city of Singapore. This was a role that the Gardens was to revisit in a major way almost a hundred years later when the Gardens focussed on the greening of Singapore in the 1970s and 1980s.
In 1990, the Gardens, under the National Parks Board, redefined its roles and goals and forged a new vision as a botanical institution with a focus on research, conservation, education and recreation. Together with other partners, it initiated a 6-year project in 1991 to survey the biodiversity of the nature reserves of Singapore. Today, the targets of the Global Strategy for Plant Conservation guide its efforts in conservation. The Botanic Gardens’ activities are focused on taxonomy and floristics of the region, capacity building and promoting education and awareness about plant diversity and conservation.
Since independence in the 1960s, the policy to green Singapore was implemented with dedicated effort and political will. It has resulted in an island almost 50% vegetated with its existing biodiversity managed and conserved and increasingly made accessible and interpreted. Its key botanical institution, the Singapore Botanic Gardens, has played leading roles in plant diversity conservation since its establishment almost 150 years ago.
I would like to thank my many colleagues in the National Parks Board who responded with information.
1 Cluny Road,