Sunday, May 2, 2010

Orania sylvicola: Palms Punctuated but Keystone

Palms are ever-present in the Lowland Dipterocarp Forest but they do not dominate like Nipah would in mangrove. The many species we have do not colonize, and even if they do sometimes, like the lofty Ibul or Orania sylvicola (featured here), they remain considerably small and limited.

I really like to think of palms as punctuation marks - small but significant - spatially spread out amongst the letters of woody trees in the sentence of a rain forest. With a minor stroke and a simple dot or two here and there, these punctuation marks breathe life to the sentence with eloquence and depth of texture and intonation. Collectively, the palm population is like that. Add all these unobtrusive individual palms in the rain forest together, you will quickly realize what a reckoning force they are. They give life to the forest.

Like energy bars they provide bountiful supply of nectar and pollen to a whole range of beetles, bees and flies throughout the year. These tireless workers swarm as cars and trucks would to patrol stations. The power food they get from palms fuels in no small part the dynamism of the entire forest ecosystem through the myriad services that they provide as pollinators of other plants, for example.

Palms also provide fruits all year round for birds, civet cats and many other arboreal creatures such as monkeys. Their leafy crown is a roosting haven for bats, snakes and lizards, and under their often broad leaf-bases the flying lemurs wait out the day in shade and security. And colonies upon colonies of ants have made rattans (climbing palms) their ubiquitous home.

So it can be seen how keystone palms are - as keystone as fig trees. When reforesting disturbed areas it bears well to remember to introduce native palms as second-stage planting under re-established trees.

In present-day Singapore, the Ibul palm (reaching 20m) are exceedingly rare and hard to find; the showy golden-brown leaf-bases is often hidden high up in the sub-canopy and obscured from view by the leafy crowns of smaller understory trees below. We are indeed fortunate to have a few living specimens extent in Bukit Timah Nature Reserve today.

Silvery greyish-brown leaflets with drooping tips.

Close-up of jagged leaf-tips.

Greyish trunk with warty protuberances.

Adventitious roots seeking the earth beneath the leaf litter.

Immature green fruits with 3 petals.

Mature fruits are highly poisonous.

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