Road & Other Urban Area
With development, many of Singapore's original natural environments have been urbanised and have been replaced by surfaces covered in impervious materials, such as concrete, stone, and asphalt. Such land cover replacements are more prominent in the Central Business District (CBD) and other industrial estates, where up to 90-100% of land is covered by man-made urban structures.
As such, urban areas in SIngapore are generally warmer, drier, noisier and more polluted than other forms of habitat. The greater temperature is attributed to the 'urban heat island effect', in which heat is trapped in urban areas due to waste heat released from vehicles and buildings, heat absorbed by dark surfaces, heat trapped by tall buildings, and lack of evaporative cooling by vegetation. This results in places like the CBD to have as much as 4-7°C higher than rural areas. The lower humidity is the result of lack of surface water for evaporation as rainwater is rapidly drained away from impervious surfaces. Air and noise pollution, on the other hand, are mainly caused by vehicles. On surfaces where soil is exposed, it is usually, aerated, poorly drained, highyl compacted and full of urban debris. The high level of disturbance and continual state of change as structures are demolished and built makes it a harsh habitat for many wild organisms.
However, since the 1980s, the garden city programme, which aims at greening the city, has introduced more roadside trees and small green pockets in the city, thus providing more complex habitat structures and refuges for greater biodiversity in the urban area.
Though a number of wild species are found in the urban area, the conspicuous street plants and urban animals that can be seen are predominantly non-native species, many of which are generally short-lived, quick-growing and fast-breeding species. For plants, many have been introduced because of deliberate cultivation as ornamentals while others are weeds brought in with other imports. As for animals, some are escapees or are deliberately released while others have followed human settlements and are still expanding their range.
Road, Parking Lot, Urban