Mangrove Forest of Bongawan River

Author
Murphy

Two weeks ago I was on a river cruise trip at Bongawan River. I was amazed by its pristine mangrove forest. So far it’s the only river cruise that let me see three mangrove zones, which have very different vegetation to one another.

Bongawan is a small town about 70 KM away from Kota Kinabalu, the capital of Sabah, Malaysia. I was told that proboscis monkey is spotted in the mangrove forest of Bongawan, so I went there to have a look.

Above: the jetty where the Bongawan river cruise starts
Normally proboscis monkey gathers on the mangrove trees of riverbank in late afternoon, so we started our tour at 4pm at a jetty in Bongawan.

Above: map of Bongawan River (Click to enlarge)
The Main Mangrove and Seaward Mangrove zones are at the left (Laut = Sea), Back Mangrove Zone at the right (KG. = Village), mainly the human settlement area. Below is the map of the jetty. Please note you need to book the tour in advance.

View My Sabah Map in a larger map

The starting point of the tour is a few KM from the sea, so the river is in normal yellow color. We explore the landward side first.

Everyone was looking for proboscis monkey, but I was having fun checking out the vegetation along the river. Many mangrove plants are useful for local community, for example, firewood, building materials, food, herb. Due to modernization, most people just buy stuffs and don’t collect what they need from forest.

At the beginning, we already see the dense clump of Nibung trees (species: Oncosperma tigillarium), which indicates the transitional area between dry land and mangrove zone. The wood of Nibung Palm can be used for minor construction such as furniture and poles for stilt houses.

Then we see many Nipah Palm, which likes to grow on soft and fine-grained substrates in the Back Mangrove Zone. Its inflorescence produces sweet syrup, which is rich in sucrose and is used for production of sugar, vinegar and alcohol. The leaf fibers are great for making ropes, brushes and brooms. The fruit (atap) is edible and a popular dessert.

The upstream dry land of Bongawan River is moderately inhabited. We passed by some villages and plantation. The density of mangrove trees here is relatively low.

Same as car for city people, boat is important for villagers living next to river. Almost every house has a “parking lot” for their boats.

Above: an abandoned boat
The boatman says this “junk” was used to be a RM200,000 luxury boat.. WOW! How and Why did it end up there then?

We saw many fruits like above. Not sure if it is the fruit of “Ketapang” tree (Terminalia catappa), which is edible.

Then our boat enters a swampy area, which is dominated by dense water grasses and Piai Raya mangrove ferns (Acrostichum aureum). The mature leaves of Piai Raya fern are used for thatching and as fodder for cattle. The young leaves are eaten as vegetable in Indonesia.

There are many “volcano moulds” built by the mud lobsters in this swamp. Mud lobster is a crustacean that looks like a hybrid of lobster and scorpion. It only crawls out of its burrow at night so it’s rare to see. Yes it is edible.

Later we turned back to move downstream toward the sea. We found long-tailed macaque, monitor lizard and a few birds (Hill Myna, Dollar Bird, Blue-throated bee eater).

Now we are inside the Main Mangrove Zone, which has the most diverse and complex mangrove ecology. This zone is characterized by abundant mangrove trees of Rhizophora species such as Bakau Minyak (Rhizophora apiculata) and Bakau Kurap (Rhizophora mucronata). The water also turns brackish and we can smell mud (like mild rotten egg).

Bakau Minyak prefers soft and muddy soil of riverbank. The wood is a nice timber for making beams, furniture, firewood, charcoal and foundation piles.

The mangrove trees of Main Mangrove Zone in Bongawan are in pristine condition. They are lush, dense and tall, some are more than 15 Meters in height.

There are 52 true mangrove plants (purely live in mangrove) in the world. 42 species are found in Malaysia, and 34 are found in Sabah. Malaysia accounts for about 3.7% (577,500 ha) of the world’s mangrove area. 59% of Malaysian mangrove forest are in Sabah.

The mangrove trees with aerial roots are Bakau Kurap (Rhizophora mucronata). It is the most widespread mangrove species in the world. Its wood can be used for fuel and charcoal. The tannin from the bark is used for tanning and dyeing of fishing lines and ropes. Usually it is scattered along the riverbank, but here in Bongawan its density is very high.

As we approach the estuary of Bongawan, we enter the Seaward Mangrove Zone.

We exit from the estuary to the open sea for a while and enjoy the mangrove view of the coastline. These mangrove trees are important natural barrier that mitigates coastal erosion, tsunami and rising of sea level.

As mangrove trees grow on tidal zone, their bases are flooded during high tide. That’s why most of them have stilt roots that serve 2 main purposes: (1) to hold itself firm in muddy soil, and (2) to breathe air during high tide.

We returned to the jetty around 5:30pm. Too bad we didn’t see any proboscis monkey. Anyway, I had joined other river cruises in south-western part of Sabah, but this is the first time I see Back Mangrove Zone, Main Mangrove Zone and Seaward Mangrove Zone in a day. For me, the flora is impressive, though the upstream area is pressured by development.

More Photos

You may check out my photo album if you want to see more nice pictures:

Photos taken in Bongawan, Sabah, Malaysia Borneo

For further information log on website :
http://www.mysabah.com/wordpress/mangrove-forest-of-bongawan-river/

The 10 Most Interesting Trees of Borneo

Most tourists have an impression that Borneo is a tropical island full of coconut trees. As a matter of fact, in only 10 sq. KM of Borneo rainforest, there are more flora than that of North America and Europe combined. Without rich diversity of tree species as a food source and habitat, our most charismatic wildlife such as orangutan would not survive.

Our trees are not boring. Let’s look at 10 of them. You would be surprised that most of them are closely related to your life.

1. Belian, the Ironman tree

Locally known as Belian, Borneo’s ironwood (Species: Eusideroxylon zwageri, Eusideroxylon means sinking wood) is the heaviest, hardest and most valuable timber of Borneo. Belian can live over 1,000 years and it grows extremely slow (mean radial rate of 0.058cm per year), reaching only a diameter of 30cm even after 120 years. That’s why it is so hard and dense that it doesn’t float on water and termites can’t bite through.

Pic: hundreds year old Belian in Imbak Canyon

Pic: 200-year-old Belian coffin in Danum Valley

However, this hardwood can’t fight chainsaw and millions of them are fallen by greedy loggers who see it as a standing gold bar. Now only a small number of Belian trees live in most remote forest of Borneo. Belian is so strong and resistant to decay that it can last 200 years in worst condition, so it’s the best wood for jetty, dock and piling. In history, China emperor used it as the pillars of Forbidden City, Murut (Borneo headhunter) used it to make blowpipe, Dusun ancestors used it to create coffin.

Pic: Murut Cultural Center supported by Belian wood pillars

2. Tongkat Ali, the Viagra tree

Ask any Malaysian what is Tongkat Ali (Eurycoma longifoliam) and note the sheepish smile on their faces. Tongkat Ali is viewed as Malaysian Ginseng and has been used as a traditional aphrodisiac. You can buy Tongkat Ali readily for cheap price at local markets and even tourist souvenir shops (it’s a hot selling item, from what I heard).

Pic: Tongkat Ali tree

Literally Tongkat Ali means “Ali’s Walking Stick.” It can grow up to 5m tall and 20cm in diameter and prefers well-drained forest slopes under partial shade. It looks like a small tree but what under its stem is long and fat root. To harvest its root, you need to tie its stem with a rope then have two men to pull it out of the soil. Tongkat Ali has two types, one with white root, which is more common and tastes really bitten, another is black color, which is better but rarer.

Pic: roots of Tongkat Ali

The root of Tongkat Ali has sexually-enhancing and testosterone-raising effect (its leaves can relieve stomach pain). The decoction of the pounded and boiled root is a popular drink to improve the potency of men hence a happy sex life. Now you even can find Tongkat Ali Coffee on the market (a few friends told me it really makes them “hard”). Hey, why bother about the expensive blue pill?

3. Strangling Fig, the tree Killer

Ever heard of a tree strangles another tree to death? This is not a fiction. The tragedy starts from a seed of strangling fig (Ficus spp) being carried in the poo of fruit-eating animals such as bird and squirrel to the treetop.

Pic: huge strangling fig trees in Maliau Basin

The seed germinates on the big tree and sucks nutrients out of it. Over time, this parasitic tree slowly spreads its branches from the crown of the host tree to the ground, the roots joined when meet, forming a basketwork of interlacing roots around the trunk. Strangling fig tree will grow faster once its roots reach the soil for more nutrients, the roots thicken and constrict the flow of nutrients of its host, eventually the host tree dies.

Pic: hollow left by the decayed host tree

The murder takes many years to happen. At the end, strangling fig wins, flowers and its fruits will attract another seed-carrier which poo on the next victim. Thing gets more interesting after the dead tree decomposes, as it will leave a hollow inside the new tree. Strangling fig sounds evil, but its fruit is an important food source for wildlife. Btw, be careful when a bird poo on your head lol.

4. Menggaris, the Honey Bee tree

In Borneo jungle, even the most casual hiker would not miss the towering Menggaris tree (Koompasia excelsa), a member of the bean family. Menggaris is a beautiful tall and straight tree which can easily exceed 60m in height and grows up to 88m, one of the tallest tree species in Borneo rainforest.

Its cylindrical bole with grey and smooth bark poses a big challenge to excellent climbers such as sunbear and orangutan. Therefore, Menggaris naturally becomes the favorite nesting tree of wild honey bees (Apis dorsata), to keep their honey out of reach to sunbear the honey lover. It is common to see over 10 bee hives under the branches of same Menggaris tree.

Pic: bee nest on Menggaris tree

Luckily, because of its hollow trunk, Menggaris is not a good timber, so you can see them remain standing on a deforested land. Villagers will build climbing aid on Menggaris tree to harvest its honey. Got honey got money.

Pic: canopy walk allows you to see Menggaris up-close

5. Gaharu, the Perfume tree

Gaharu (Aquilareia malaccensis) is also known as agarwood, incense wood and aloeswood. This intensely fragrant resinous wood is widely used in religions (some even calls it the “Wood of the Gods”), probably it resembles the smell of heaven so its price is sky high too, at least US$1,000 per Kg. There have been local and foreign thieves who trespass our protected forest to collect agarwood illegally.

Pic: Gaharu tree in Tawau Hills Park

Pic: agarwood products for sale

Normally the wood of Gaharu tree is white and has no odor. But if the tree is infected by fungus, it’ll produce dark aromatic resin to protect itself. This agarwood is not only highly prized as an incense, it is an important ingredient for perfume industry.

Pic: Gaharu tree cut by thief

6. Mangrove, the Summer Xmas Tree

Growing in smelly and muddy swamp land, how can mangrove trees (Rhizophora spp) be interesting? In old days, mangrove forest was considered a wasteland full of mosquitoes, and people weren’t hesitant to clear it. Now we know that mangrove ecosystem serves an important role in flood mitigation, prevention of coastal erosion and as a feeding ground for migratory birds.

Pic: note the breathing roots of mangrove trees

Sabah occupies 59% of total mangrove area in Malaysia. Mangrove is the nursery of seafood and that explains why Sabah is abundant in seafood. Mangrove is also the habitat of Proboscis Monkey, our endemic Borneo monkey which attracts a lot of tourist$. At night, hundreds of firefly congregate and twinkle on mangrove, turning the tree into a Summer Xmas tree. Nowadays, the well-being of our seafood and tourism industries depend heavily on healthy mangrove.

Pic: proboscis monkey family on mangrove tree

Pic: vivipary, the spear-shaped seed of mangrove

Living in tidal zone, mangrove tree develops many interesting features to adapt to this harsh environment. It uses stilt roots to breathe and hold itself firm in the mud. Its torpedo-shaped seed (vivipary) may look peculiar, but it helps the seedling to anchor in the soft substrate when detached from mother tree.

Pic: firefly Summer Xmas Tree in Klias Wetland

I would say mangrove tree is the most useful tree because it benefits everyone of us.

Pic: river of mangrove is always a good spot for fishing (watch out for crocodile though)

7. Oil Palm, the Money tree

Well, oil palm (Elaeis guineensis) is not so “Borneo” but this native species of West Africa has blanketed nearly 20% of Sabah, the largest palm oil producing state in Malaysia. Now oil palm is a cash crop so it is quickly turning swaying coconut and banana trees of countryside into ugly palm. Palm oil also enters every corner of our lives, from soap, shampoo, cooking oil, chocolate, margarine, cosmetic, detergent to biofuel.

Pic: forest engulfed by oil palm

To be fair, the yield of oil palm per hectare is 10 times more than soybean and sunflower. The crop itself doesn’t cause any problem, only the way how it is planted is earning it a bad name among environmentalists, for example, open burning, deforestation, hill clearing and encroachment to riparian reserve. Anyway, now the government, NGOs and plantation owners are willing to work together to ensure sustainable and environmentally-friendly practices are in place for this crop.

Pic: elephants (right) roaming near a deforested hill

8. Sago Palm, the Edible tree

You may start imagining that you are ordering a piece of wood off a restaurant menu and then biting it like a white ant, or a starving man chewing tree bark. Sago palm (Metroxylon rumphii & Metroxylon sagu) is really edible but you have to process its trunk first.

Pic: the pure carbohydrate from sago palm saved many lives in WW2. Sago Palm is also called The Tree of a Thousand Use. You can use its leaves to make handicraft and roof, and its trunk to build houses, etc.

Sago is one of the staple food for people living in south-west of Sabah (Kuala Penyu and Beaufort) and they even celebrate Sago Festival annually. To extract the starch of sago palm, they pound the soft kernel of the trunk into chips, wash the pulverized pith with water, collect the starch and dry it. Sago can be made into different delicious food such as cake and pudding, and the traditional way to enjoy it is to make Ambuyat, a translucent and sticky sago paste, which is served with fish and sour soup.

Pic: the traditional tool of sago processing. Now it’s replaced by machine.

Pic: Ambuyat.. yummy..

During sago processing, the farmers also pick up some wiggling fat larvae of beetle (Butod) which is well-fed in kernel. Some locals consider this juicy butod a delicacy and love to eat it alive. Are you keen to try?

9. Pelawan, a Naked tree

There is a Chinese proverb says, “Man needs face as much as tree needs bark”, so I was surprised to see Pelawan tree (Tristaniopsis spp), which is a member of the Myrtaceae and quite common in lower montane forest of Sabah highland.

About 20 species of Pelawan are found in Borneo and these bizarre trees are characterized by flaky orange bark. The tree is so beautiful that there is a story which says other trees were so jealous of its fashionable peeling bark that they beat it with branches.

Pic: Tristaniopsis tree in Long Pasia

This phenomenon is just a growing process of Pelawan, the old bark peels off when the fresh bark emerges.

10. Kerosene tree with Petroleum Nut

If your tour guide brings you to Botanical Garden of Kinabalu Park, he will definitely show you a cool trick by igniting the fruit of Kerosene tree (Pittosporum resiniferum) like a candle. Yes, the fruit of Kerosene tree is inflammable and can be used in producing biofuel. This tree is less than 10m tall and grows between 400m and 2,300m above sea level. In old days, locals use the oil of this fruit for lamp.

Pic: fruits of Kerosene tree (Source: Dick Culbert)

Some birds eat this fruit, but it is unclear that if it can help the birds to achieve sonic speed in flight. Just kidding.

The list doesn’t end here. Borneo also has the Tallest Tropical Tree in the World. Please share with me in comment section below, if you know other interesting trees of Borneo.

Photos taken Sabah, Malaysia Borneo

For further information log on website :
http://www.mysabah.com/wordpress/10-interesting-trees-borneo/