Monday, 25 January 2016

NSS Kids’ Fun with Forest Giants at MacRitchie Reservoir (Singapore)

By Gloria Seow

Education Committee Chairperson

Uncle Tony leading a young entourage through the wonderful world of plants.
The allure of meeting Forest Giants up close was enough to attract a sizeable number of kids and their families to MacRitchie Reservoir (off Lornie Road in central Singapore) on the morning of 23 November 2014. Plant Group Chairperson Uncle Tony O’Dempsey was our esteemed guide, assisted by Auntie Angie Ng. Uncle Tony maintains an informative compendium on Singapore’s flora at

Uncle Tony started by pointing out shrubs such as the Simpoh Air (Dillenia suffruticosa) as we trooped from the Visitor Centre towards the forest proper. Along the way, Auntie Angie paused under a prominent Banyan Tree (Ficus microcarpa), and told us that this strangling fig started life as a hemi-epiphyte. This is when their seeds (usually dispersed by birds) germinate in crevices on trees and even buildings. They eventually envelop their host tree with their spreading prop trunks and roots. The original support tree can die from this ‘strangulation’. The strangling fig then becomes a ‘columnar tree’ with a hollowed core. Uncle Tony also introduced two types of Pulai (Alstonia angustiloba and Alstonia scholaris), where both can be differentiated by variations in leaf venation and patterning. Both Pulai species can be found on the hillock that houses war hero’s Lim Bo Seng tomb.

Auntie Angie highlighting the strangling nature of the Banyan Tree.
We then entered the cool forest trail that runs parallel to Lornie Road. Uncle Tony showed us his favourite rattans. Rattans have spines on their stems and leaves that serve to protect them from herbivores and help them cling to the trunks of trees for support. They can reach hundreds of metres long. In many tropical countries, people harvest rattans to make lightweight and durable cane furniture or weave them into baskets and other craft. Uncle Tony pointed out two types of Macaranga (Macaranga gigantea and Macaranga bancana). Of the 11 species of Macaranga found in Singapore, eight of them host ants in their hollow twigs and produce food-bodies which supplement the ants’ diet. In return, these ants protect the Macaranga from invasion by insects such as caterpillars.

A Forest Giant with mighty buttress roots, a long straight trunk, and a spreading crown that towers over the canopy.
Kids were suitably impressed with the few Forest Giants that we came across. Typical of primary forests, Forest Giants are dominated by dipterocarps in the genera Shorea, Dipterocarpus and Anisoptera. These are characterised by long straight trunks reaching up to 50 metres, buttress roots and broccoli-like crowns that break through the main canopy. Also called emergents, these trees can be hundreds of years old.  

Uncle Tony sharing about the importance of the rainforest.

We encountered many other wonderful plants. There was a patch of Slender Pitcher Plants (Nepenthes gracilis) with a profusion of dangling pitchers that serve as traps for insects, particularly during rainfall. The insects drown and are digested, benefiting the plant with mineral nutrition (especially nitrogen and phosphorus) and protein. Such carnivorous plants are able to colonise areas with mineral-poor or overly acidic soil too tough for most other plants to survive. The walk ended with several animal sightings: frolicking Long-tailed Macaques (Macaca fascicularis), a dried-up Green Paddy Frog (Hylarana erythraea) and a 1.5 m long Malayan Water Monitor (Varanus salvator).                                                                                                              

Frolicking Long-tailed Macaques (Macaca fascicularis),

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