Ecosystem - Coastal Forest of Chek Jawa

Naked Facts:

Interactive Question:
Question: Now let's observe, can you find any differences between the coastal forest and mangrove forest?

Possible Answers:
1) The mangrove forest is sometimes submerged in seawater while the coastal forest is not submerged in water.
2) The roots of the mangrove trees have weird roots (you can talk more about them at the mangrove forest) while the trees at the coastal forests do not.

NF#1: Source of Nutrient AKA Food for marine life at the shore
a) When it rains, nutrients from the soil, fallen leaves etc and minerals from the rocks are washed down the slopes of the coastal forest
b) These are in fact considered ‘food’ for many marine flora and fauna living in the inter-tidal zone.

NF#2: Natural wind buffer
a) Imagine a natural wall which is steep and built up of rocks and vegetation.
b) It helps to lessen the impact of strong winds from storms, hurricanes etc.

NF#3: Place to find rare and unique plants + jungle fowl
a) The plants you find at coastal forests can be given the titles of ‘survivors’, as they are constantly exposed to strong dry winds, salt sprays, the hot temperature.
b) Due to development, we do not have a lot of places left in Singapore with coastal forests now, think Labrador Park, Sentosa and Chek Jawa.
c) Native Jungle fowls are also known to live the coastal forest of Chek Jawa.
d) Some rare/unique plants found at the coastal forest include the Seashore Nutmeg, Pong pong tree and Delek air tree etc. Read more about them here.

More reading:
To read on showy and interesting plants found at the Coastal forest, click here.

Simple Drawing on coastal forest ecosystem, worth a look!
http://www.eart-h.com/text/hillpix.htm

Reference:
http://www.eart-h.com/text/sea4rest.htm

Jejawi Viewing tower

NF#1: The tower is 20m tall and allows visitors to get a good view of Chek Jawa and the surrounding areas. Due to it's height, the tower is also a great place to spot birds on nearby trees. This tower can take a maximum of 40 people.


NF#2: The Jejawi Tower is named after the Malayan Banyan (Ficus microcarpa) growing nearby that was as tall as the tower. The Malayan Banyan is a fig tree. As fig trees produce figs very regularly, they are able to provide regular food supplies for all kinds of animals such as birds and monkeys, unlike other forest trees that fruit perhaps once a year or even once every few years. In fact, such large fig trees play a critical role in providing food and shelter, and studies suggest the number of such fig trees limit the number of animals found in a forest.

Interesting Note: To connect visitors to figs, guides who understand Chinese can ask the visitors if they know the popular oldies "榕树下"(pronounced as Rong Shu Xia), which means "Under the Banyan Tree". Or has anyone eaten "无花果"(pronounced as Wu Hua Guo), which is also a fig. Do explain to the visitors that "无花果" actually do flower, just that the flowers are concealed within the fig. And what they are eating is not really the fruit, but a natural container for the flowers and seeds!

Too Much Information:

Figs are pollinated by tiny fig wasp that are mostly smaller than the head of a pin!

The female wasp somehow finds the correct fig tree in bloom, and sometimes, she must fly a long long way!

To get to the flowers, she squeezes through a tiny little hole in the fig. In the process she loses her wings and most of her antennae.

Usually, there are 3 types of flowers inside the fig:
1. Male flowers near the tiny hole
2. Female flowers with short styles
3. Female flowers with long styles

The male flowers are still immature without pollen. As the female wasp moves around in the fig, she transfers pollen she collected from her previous fig to the female flowers.

She will lay eggs in the female flowers with short styles. After laying the eggs, she dies.

After some time, the baby wasps hatch and feed on the plant tissue surrounding them. The males will hatch first. They are wingless but have strong mouth parts.

Meanwhile, the female flowers with the long styles develop seeds.

Once the male wasps become adults, they will seek out the female wasps and mate with them. After mating, the male wasps will chew and enlarge the tiny hole to create a wider tunnel so that the females can depart without losing their wings. The males usually die soon after they enlarged the tunnel.

As the females leave the fig, they pick up pollen from the male flowers that are now mature.

After they leave, the fig ripens and the walls become yummy to eat. Animals eat the fig and disperse the seeds.

Meanwhile, the brave little female wasp flies on to start the whole cycle then starts all over again.

Additional info on fig and fig wasp:
- The Fib Web
- The Last Stand of the Male Fig Wasp
- One Fig, One Wasp? Not Always!

Fruits trees of Chek Jawa

Rambutan (Nephelium lappaceum)
Among our favourite fruits, there are lots of rambutan trees throughout Pulau Ubin. And some on Chek Jawa too.

Jambu bol (Syzygium malaccense)
There are several of these large trees on the way to Chek Jawa and at Chek Jawa. The pom-pom like flowers are bright pink, and turn into oval shaped jambu. Apparently this jambu is very delicate and thus hard to bring to market. So you can only eat it at Pulau Ubin!

Coastal forest specials

Here are some showy and interesting plants that you might come across in the coastal forest of Chek Jawa.

False coffee plant (Fagraea racemosa)
These tall bushy plants grow under the rubber trees in the coastal forest near Chek Jawa. Once in a while, they produce large white flowers that turn into bright green fruits.

Wild ixora (Ixora congesta)
Called 'Jarum jarum' in Malay, which means 'bunch of needles'. Quite appropriate a name especially before the buds of the orange flowers open. These wild cousins of our garden ixora only bloom occasionally. But when they do, the dark gloomy floor is splashed with colour.

Rattan
These vigorous climbing palms can be seen from the boardwalk. Their antennae-like tips poking out of the forest canopy. Rattans usually have lots of spines everywhere to help them clamber up trees to reach the sunlight. The spines on leaves often catch on forest trekkers' clothing. So the plant is sometimes also called the 'wait-a-minute' plant.

Rattans produce fruits encased in a scale-like covering. Some are edible.

Rare coastal forest trees of Chek Jawa

These trees of Chek Jawa's coastal forest are considered rare simply because most of Singapore's coastal forest habitats have already been cleared.

Nyatoh tree (Pouteria linggensis)

Pong pong tree (Cerbera odollam)
The Pong pong trees we see on growing our streets are from Malaysia. Our native Pong pong trees are very rare as most were wiped out as our coasts were developed. There are still a few native Pong pong trees on the shores of Chek Jawa, clinging onto the rocky cliffs.
Fruits are poisonous and often used as rat poison and for stupefying fish in small streams. Oil from seeds is rubbed on the body to treat cold, rheumatism and scabies. The latex is applied to sores and also as a remedy for stingray poison.

Delek air tree (Memecylon edule)
There are several of these rare and beautiful trees on the coastal hillside of Chek Jawa. The bluish purple flowers turn into red be


Sea shore nutmeg (Knema globularia)
There are several of these trees in Chek Jawa's coastal forest. Hornbills love to eat the fruits.

Trees on the shores

Sea almond (Terminalia catappa)

Called 'Ketapang' in Malay, young small trees may be seen on the coast. The broad leaves may all turn red at the same time, giving the feeling of autumn on the shore.

The tiny white flowers turn into almond shaped fruits that are green when young and become brown and woody as they mature.

It is a common wayside tree in Singapore can be seen along Jalan Eunos/PIE going towards Changi and East Coast Park.

The leaves shed twice a year, usually from yellow to orange and to maroon colour and it finally drops off the tree but sometimes drop when it turned yellow. After the crown is bare, new leaves develop, after which the tree flowers. Fruits are also disperse by fruit bats and floats on the sea for days before reaching the shore and germinating.

Fruit has a thick husk and its kernel can be eaten taste which taste like almond. The timber can be used for building houses and boats. Fish hobbyist and some aquarium shops will usually soak these dried leaves into fish tank, especially for fighting fish because it produce tannin which believed to be good for their scales.

Alexandra laurel (Calophyllum inophyllum)

Called 'Penaga Laut' in Malay, this tall tree has beautiful white flowers that turn into round hard fruits. The broad shiny leaves have fine parallel veins.

Bushes on the shores

Sea hibisicus (Hibiscus tiliaceus)

Can grow quite tall and bushy, identified by the heart-shaped leaves that have tiny slits on the veins on the underside. These slits produce a substance that attracts ants.
The flower is yellow when it first blooms, turning orange as it ages. This develops into a pod that splits open when ripe to reveal little seeds. Small Cotton stainer bugs feed on the seeds and during a fruiting period, there can be lots of these colourful bugs.

Sea lettuce (Scaveola sericea)

The shrub can be quite tall and bushy. Leaves large and waxy. The little white flowers have a unique structure developing into a round fruit.
Chengam (Scyphiphora hydrophyllacea)

A rather small shrub, with small flowers in clusters, developing into oval fruits.

More about some of these plants
on the Guide to the Mangroves of Singapore
Chengam (Scyphiphora hydrophyllacea)
Sea Hibiscus (Hibiscus tiliceus)

Raffles' pitcher plant (Nepenthes rafflesiana)

nepenthes rafflesiana lower pitcher
Originally uploaded by budak.

The coastal forest of Sarang Rimau at Siloso has a good number of Raffles' pitcher plants, which grow as mature vines that clamber and dangle from the larger trees. They are a carnivorous plant species and should be not confused with the plants known as Rafflesia, which are also vines but parasites with no leaves but very large flowers (and are not found in Singapore).

Pitcher plants have specialised leaves that form containers with fluid that is able to digest small animals from ants to even vertebrates like rats. The pitchers are an adaptation that allows the plant to survive in poor soils and other environments where nutrients are deficient and where most other plants cannot thrive.

nepenthes rafflesiana upper pitchers
Originally uploaded by budak.

The pitcher even has a 'lid' on top which is thought to help provide shade against rainwater that could cause the pitcher to overflow. Like most other Nepenthes species, N. rafflesiana produces two types of pitchers: upper and lower. The lower pitchers are produced on branches closer to the ground and are goblet-like, with two 'wings' that may serve to stabilise the pitcher on the ground. They are also much more colourful, with a marbled pattern, especially on the edge of the pitcher. Upper pitchers are slim with a tapered end and are produced on the higher vine-like portions of the plant.

Many small animals meet their doom in the pitchers, but there are also a few which can survive or even make a living from the pitcher plants. Some species of mosquitoes (not the disease-causing types) breed by laying eggs in the pitchers, and the larva feed on the remains of victims in the pitcher fluid. A species of crab spider can also be found which specialises on catching insect prey that approaches the pitchers.

Angsana: The Breakable Tree

NF#1: The angsana tree (Pterocarpus indicus) was introduced into Singapore in the early 19th century. It is native to the southern part of the east coast of Peninsular Malaysia. The tree was introduced to provide shade as it is quick growing and easily transplanted.

NF#2: However, mature trees are known to have a weak structure, and break easily, especially during stormy weathers. Being a roadside tree, it is thus a potential hazard for vehicles and nearby buidlings. This is also probably the reason why this tree looks like this now.



Joke: Ahem, this tree always remainds me of some people I know - those who appear strong and hardly outside, but turn out to be weaklings.

NF#3: Angsana wood is said to be the best fine-furniture wood in Malaysia. It is used to make tables, chairs, cabinets, and decorative items.

Too Much information
You will be quite lucky if you can see the flowers, as they usually last for only one day. The flowers are small, yellow and faintly fragrant. They grow in large bunches 15 to 30 cm long.