Straits Times 17 May 13;
I REFER to Dr Wee Yeow Chin's letter ("Wild growth alone won't make S'pore a global eco-city"; May 8).
The satellite study (The Gardens' Bulletin Singapore, 2011) I referred to in my commentary ("Wild greenery makes S'pore a global eco-city"; May 1) states that out of the 29 per cent of "spontaneous" or "non-managed" greenery, scrubland comes to only 6 per cent, with "the majority (21 per cent)... secondary forest of various kinds".
Given the 5 per cent within the nature reserves, this still leaves about 16 per cent unprotected. Relative to the small size of Singapore, this remaining unprotected greenery is "massive".
The National Parks Board's (NParks) reforestation programme in the nature reserves mentioned by Dr Wee is highly laudable. This is to rectify severe fragmentation within the boundary, but this is a different, although related, issue from the increasing isolation of nature reserves in the wider ecological context that I have emphasised.
Dr Wee states that if "natural greenery is removed and replaced with trees and parks, biodiversity will be compromised", but biodiversity will improve over time as the plants mature. This merely whitewashes the damage that has occurred. And if allowing for the subsequent growth of "natural greenery" will improve the biodiversity loss, why remove the natural greenery in the first place?
Would it not be better ecologically to accommodate the natural greenery as much as possible, as I have advocated with the creation of 20 new parks?
Dr Wee mentioned Bukit Batok Nature Park - a good example of creating a park by not destroying all or most of the existing natural greenery (mainly secondary forest) and starting from scratch.
Concerning NParks' commendable hornbill conservation project, it was in 2006 that an artificial nest on Pulau Ubin was used by oriental pied hornbills. But they were already using natural cavities in 1994, when they were first sighted there. The use of natural cavities was also recorded in Changi. Hornbills have been sighted around patches of forest and mangrove in Pasir Ris and Sungei Buloh before the setting up of nesting boxes there, showing that the presence of natural greenery as sources of food and cover contributes importantly to the dispersal of these hornbills.
It is noteworthy that the appearance of wild hornbills on Pulau Ubin after a long hiatus happened around the early 1990s, when the island was largely becoming wild with the phasing out of agriculture. Without the nestboxes, the appearance and dispersal of the hornbills in Singapore would have proceeded anyway, but at a slower pace and in smaller numbers.
Ho Hua Chew (Dr)
