Journey to the wild

On 25 June 2009, Thursday, five tourists, namely Almas, Chunni, Hannah, Jean and Iris took a trip to Sungei Buloh Nature Reserve to learn more about to mangrove forest in Singapore.
They met at Kranji MRT station at 10.30am. They then boarded bus 961 towards their destination.

On the way to Sungei Buloh Nature Reserve...

After a tiring half an hour walk, they finally arrived at their destination, Sungei Buloh Nature Reserve. High spirited, they entered the entrance, paying a mere fee of fifty cents for the entrance fee.

Before they could start on their learning journey, a komodo dragon appeared in front of them, blocking their pathway and deterring them. They had no choice but change their course of direction.

They've learnt a lot of new things after the trip because characteristics that Sungei Buloh has is very different from some of their home countries.

introduction

Singapore is located at 01°22'N of the Equator and thus experience the tropical equatorial climate so mangroves thrive here in the sheltered coastal regions as there are high temperatures of 26.8 °C with temperature range of 1.8 °C and high annual rainfall of 2400 mm.

Mangroves forests are found in areas flooded by coastal tides and along rivers.
It also has three distinct horizontal zones : coastal, middle and inland zones.
Unlike the tropical rainforest, there are no vertical layers in a mangrove forest.

Trees vary in height from 2-40 metres although their average height is 15 metres, which is shorter than the tropical rainforest.
This is because the muddy soil cannot provide firm support for very tall trees to grow.

When we arrived, the coastal zone is flooded with seawater during high tide and thus we are not able to see most of the plants on low ground. ):

The Avicennia and Sonneratia trees are common in this area as they have breathing or aerial roots and are adapted to growing in salt water.
Their roots are in soft, water logged soil which are deprived of oxygen now (a condition called anaerobic).

However, at low tide, the aerial roots are exposed and can take in oxygen. The Avicennia roots (pneumatophores) are pencil-like, branched upwards from the main horizontal roots that grow below the soil. These roots allow the absorption of atmospheric oxygen through specialized root cells known as lenticels and grow up to 30 cm, while the Sonneratia roots are thick at the base and peg-like.

In the middle zone, Rhizophora trees grow densely here and they have prop or stilt roots like this!

These roots branch from trunks like stilts. This helps to prop up/anchor the trees firmly in the soft muddy soil so that it will not topple with the ebbing and rising tide.

We went along a trail in the inland area, like this:

The Bruguiera trees grow here, as they are least tolerant of saltwater and have kneed roots. They can grow up to 25m tall. The bark has pores (lenticels) that allow for gas exchange, an adaptative feature to the low oxygen content in the mud.

Flora and Fauna of Sungei Buloh

There is so much to see at the Sungei Buloh Nature Reserve!

So...

Monitor Lizards are found at the Sungei Buloh Nature Reserve. Growing up to 2 metres, the Monitor Lizard is the largest lizard found in Singapore. This creature can often be seen sun-bathing on the walking routes! (As we had experienced! :o) Fear not, as when disturbed, it will clumsily escape into the undergrowth or water. It is an excellent swimmer, living near water where it scavenges.

We were the lucky few who managed to catch sightings of a few species of birds (though not all species) such as shorebirds and egrets.

Shorebirds

Shorebirds are called so because they wade in the shallow water in search of food. Plovers and sandpipers are common waders found in the reserve. With their different bill length and feeding habits, they are able to tap on different food sources found in the mudflats. This enables them to co-exist in the same habitat.

Egrets

Egrets at the reserve are white and more slender than herons in appearance. They are frequent visitors during the migratory season. The Little Egret is often seen dashing about, chasing after its prey in the shallows.

Atlas Moth

The Atlas Moth is the largest species of moth found in Southeast Asia. During the breeding season, the Atlas Moth lays its eggs on the leaves of the Sea Poison Tree. The fat, lime-green caterpillar can be seen munching on these leaves before turning into cocoons.

We did not have the luxury to see the beautiful sea creatures such as crabs, the Mudskipper, the Mud Lobster, barnacles and the Leaf Oyster which are also found in the mangroves. However, we did see signboards and posters put up to ensure that the lives of these sea creatures are not endangered.

Flora

Mangrove flowers are intricately designed and some are colourful. Pollinators of these flowers include birds, moths, bats and wind.

Some seeds germinate on the parent plant before they detach and fall to the mudflats to begin life on their own. Through this adaptation, the seedlings are able to take root immediately in favourable conditions, thus increasing their chances of survival.

Leaves of the Mangroves

The leaves of the mangrove forest are evergreen. This is because there are no seasonal changes in both the temperatures and rainfall in the tropical climate. For the Mangroves, they experience tropical equatorial climate as mentioned above, hence their leaves are evergreen.

An example of an evergreen leaf taken in the mangrove forest

In addition, due to the high rainfall throughout the year, the leaves are broad and have drip tips, just like those in the Tropical Rainforest. The leaves have such adaptations because this allows water to flow off the leaves quickly. Due to the high temperatures, the surfaces of the leaves are thick and leathery to reduce water loss during transpiration.

As you can see, the leaves have a broad structure

An example of a broad leaf with drip tips

An example to show that the surface of the leaves are thick and leathery

To enable mangrove trees to grow in salt water, the leaves are uniquely adapted to regulate the amount of salt in the tree. As the mangroves forests consist of four different species, mainly the Avicennia, Sonneratia, Rhizophora and Bruguiera, each tree has leaves that have different adaptations.
For example, species such as the Avicennia are salt secretors. They secrete excess salt on their leaves, which will them be removed by the wind or rain.

This is an example of a Avicennia leaf

This is an example of a salt-secretor leaf

The Bruguiera, Rhizophora and Sonneratia species are known as ultrafiltrators. They absorb salt instead of secreting it. The salt will then be removed by the species as they are stored in old leaves which will then fall off in the end.

An example of a Sonneratia leaf

An example of a Rhidzophora leaf

To end off this part of the mangroves, the five tourists have taken a brief video of the structure of a real Mangrove tree.

This video shows the structure of the Mangroves which are divided into three distinct zones.

This video shows the thick canopy that the mangrove trees have.