The primary forests in Singapore are quite similar to the forests in other countries in South East Asia. Though speaking about mammalian fauna Singapore has always had a less diverse population. In historical times (before major human influence) there were for example no gibbons, tapirs, rhinoceroses and wild cattle. Singapore has also fewer species in animal families than comparable areas. This is because the Island got isolated by increasing seawater. The high seawater level became a barrier for big mammals to migrate to Singapore. Naturally, nature itself is not the only factor that influences animal and plant diversity. Obviously the biggest factor is human influence.

‘Obviously the biggest factor is human influence’

Raffles discovered the island in 1819 and from this moment it went even more downhill. At that moment the island had a population around 150 people, but the population grew exponentially when the British expanded their trading centre. Simultaneous with the increasing population the cultivation grew. In the beginning the local population only had some crops near the borders of the forest, but it spread quite fast to the midlands.

 

The crop that had the most impact on the forests was gambier, which was used as a tanning agent. Gambier grows best on newly cleared forest, besides this every plantation needed lots of firewood to boil the gambier leaves. Every plantation needed an equal amount of forest area, in order to provide the firewood. After 15 years of gambier cultivation the soil gets exhausted, so the consequence of this was that the farmers had to clear a new piece of forest every 15 years.

While gambier plantations destroyed the inland forest, the costal forests were cleared by coconut cultivation. The remaining parts of the forests were exploited for timber, latex and other forest products. In 1847 almost all the trees from the family palaquium gutta were eliminated, because of their latex. The gambier cultivation stopped around 1890, but new plantations took over their places. Like indigo and pineapple, these plantations got especially popular after the introduction of canning. At this time rubber became a popular product as well, so the rubber plantations grew increasingly. In 1935 40% of the land area was used for rubber plantation.

 

The mangroves were cleared for charcoal and firewood in the beginning. After 1900 the biggest threat for the mangroves was enclosement to form brakish water in order to farm shrimps. Since 1970 the barricading of mangroves to create freshwater reservoirs was the main factor for mangrove loss.

Nowadays Singapore barely has plantations and cultivation left. The main reason for decreasing forests is urbanisation, this was caused by a shift in economical development. The population grew from 150 individuals in 1819 to more than 5.5 million today. This significant growth went at the expense of the forests. The only primary rain forest left is Bukit Timah Nature Reserve. More than 95 per cent of the estimated original vegetation cover has been entirely cleared. All the nature left can be found in nature reserves like this, it makes up 0.25 per cent of the total land area.

 

Another cause of extinction is hunting of animals and collecting of vegetation. So, loss of habitat for Singaporean species is mainly caused by human influence, although there are nature reserves spread over the country the level of fragmentation is high. The habitat of an organism can become too small for particular big mammals to sustain their life.