At one point, Singapore was covered with dense lowland tropical rainforest, with mangrove forests along the muddy coasts and tidal creeks. As the settlement increased in 1840's, forests made way for cultivating of crops like nutmerg, gamlier, clove, pepper and cocoa. As a result of deforestation, many endemic plant species, including 50 species of mangrove inhabitant orchids, disappeared.
At the turn of century, forest reserves were set up. At present National Parks Board (NParks) takes care of about 3000 hectares of Natural Reserves, the Bukit Timah Natural Reserve, the Central Catchment Nature Reserve, the Sungei Buloh Wetland Reserve and the Laborador Nature Reserve.
The 164 hectare Bukit Timah Nature Reserve and some part of the Central Catchment Nature Reserve have primary forest in Singapore. They account for the last remaining traces of primary rainforest in Singapore. The main vegetation is the tropical hardwoods of the Dipterocarp, which can in some cases, grow up to 40 metres.
On the coastal side, one can find the mangrove forest in places like Kranji, Sungei Loyang and Sungei Tampines near Pasir Ris . The beaches in Singapore have a variety of vegetation ranging from grasses, sedges, creepers and trees. Red seaweeds, Green seaweeds and Brown seaweeds can also be found along the coastal areas.
Singapore has 80 species of mammals, over 300 species of birds, around 60 freshwater fish species and 110 reptilian and amphibian species. The Nature Reserves, the Northern Islands Of Pulau Ubin and Pulau Teking account for most of the native animals. In the top tree line, one can find Flying Lemur, the Flying Lizard and Long Tailed Macaque. Shrews, rats, snakes, skinks and frogs inhabit the forest floor. The various bat species include fruit bats, horseshoe bats, the sheath tailed bats and the false vampires.
In the streams, ponds and reservoirs, one can find tadpoles, fish (Rasbora and Puntius), prawns; water bugs and dragonfly and damselfly nymphs. Three out of the seven species of freshwater crabs are endemic.
Mussels, barnacles, snails, crabs, mud lobsters, prawns and mud skippers are found along the coast line. The coastline also supports other eco systems like coral reef. The Sungei Buloh Wetland Reserve is home to 180 species of birds.