SINGAPORE \u2013 Khaya trees introduced here in the 1980s have become a common streetside feature, their dense canopies providing shade and greenery. <\/p>\n
But these trees, along with sea apple trees, are now being felled in HDB estates and other areas, to some residents\u2019 dismay.<\/p>\n
Bukit Panjang resident Christina Lee, 45, observed the Khaya trees in her HDB estate being cut down last month. She said she was unaware of the reasons behind their removal, although she had surmised that they were removed out of safety concerns.<\/p>\n
\u201cSince the trees were quite old, it\u2019s a bit heartbreaking to see them go,\u201d she added. \u201cIt\u2019ll take a very long time for the trees to grow to that size.\u201d<\/p>\n
Khaya trees, also known as Senegal mahogany, are native to Africa. They were first used for roadside planting because of their rapid growth rate and ability to tolerate dry urban environments.\u00a0They can reach 30m tall.<\/p>\n
National Parks Board group director for streetscape Oh Cheow Sheng said Khaya (Khaya senegalensis)<\/i> and sea apple (Syzygium grande)<\/i> trees have been observed to be susceptible to basal rot \u2013 a fungal disease that causes decay at the base of a tree. <\/p>\n
Damage to a tree\u2019s anchoring roots can lead to tree failure \u2013 the breakage of the trunk, branches or roots \u2013 which may damage the tree\u2019s surroundings or injure passers-by. <\/p>\n
Such trees are now being removed in HDB estates and spaces managed by NParks for safety reasons. <\/p>\n
\u201cPlanted decades ago, many of these trees have also outgrown their growing spaces, which now limits continued root growth and affects their long-term health,\u201d Mr Oh said, in response to queries from The Straits Times.<\/p>\n Khaya trees, also known as Senegal mahogany, are native to Africa. <\/p>\n ST PHOTO: JASEL POH<\/p>\n<\/figcaption><\/figure>\n \u201cTrees that show signs of disease, are in poor health or structural condition, or are growing near areas with high human traffic or in limited growing spaces are prioritised for replacement.\u201d<\/p>\n Associate Professor Adrian Loo, deputy director at the NUS Centre for Nature-based Climate Solutions, explained that as the natural habitat of Khaya trees is drier than Singapore, the trees may become susceptible to disease or vulnerable to tropical storms as they age.<\/p>\n \u201cWith climate change, more adverse weather conditions during the monsoons might also cause more tree falls in this tree species with a weakened root support,\u201d added Prof Loo, who has a background in botany. <\/p>\n Mr Oh said NParks has been progressively replacing the trees with both introduced and native species deemed better suited to Singapore\u2019s environment, such as the rain tree (Samanea saman),<\/i> shore laurel (Neolitsea cassia)<\/i> and sea gutta (Planchonella obovata). <\/i><\/p>\n \u201cTrees assessed to pose a lower risk to public safety \u2013 such as those located in forested or open areas away from buildings or human traffic \u2013 will be retained,\u201d he added. <\/p>\n \u201cIn some places, where possible, replacement planting will be carried out prior to tree removal to mitigate the loss of greenery.\u201d<\/p>\n NParks engages in the selective replacement of trees and the introduction of greater species diversity to sustain a healthy, resilient urban forest while ensuring public safety, said Mr Oh.<\/p>\n<\/picture><\/div>