Friday, September 14, 2007

Mangrove Ecology at Sungei Buloh

Thursday afternoon, a big bunch of learning "ecologists" from NUS went to Sungei Buloh Nature Reserve for a field trip to study mangrove ecology. And believe me, everytime you go, there is something new for you to be marvelled at.

If you enter through Kranji, you might come across this railway crossing which has only one lane for a two-way traffic. Therefore, traffic jam always occurs near here though this place is not every populated.

Upon reaching the nature reserve, we were introduced to zonations based more on topography than species since our "compressed" mangroves are more heterogenous as compared to other undisturbed mangroves elsewhere from Singapore. From landward to seaward, the zonation goes like this: Back mangrove, mud lobster mound system, main forest, sandbank and then mudflat. One thing about the diversity of mangrove plants as compared to that from tropical rainforest is that species diversity is low as few plants can tolerate low oxygen, high salinity conditions.

Our first station is the back mangroves where it is found at tidal heights beyond where the highest water spring tide occur. What dominates the back mangrove will be Sea Hibiscus.

The next zonation will be the mud lobster mound and pool system.

Over here, the mud lobsters dig mud and unknowingly, they create huge mounds which are analogous to condominiums, even with swimming pool, in the forms of water pool. The height of the mound is advantageous to those plant which cannot tolerate salt because these plants can grow on the sides or on top of these mounds and be higher up from the salty water of the incoming tides. Growing on these mounds are mangrove ferns...

and sea holly. These plants can be identified by its jagged edges.

The main forest zone of Sungei Buloh is highly disturbed and therefore has more species of plants in a small area as compared to undisturbed mangroves. The common mangrove trees include the Rhizophora tree with stilt aerial roots, Bruguiera with knee like roots (as shown above) , and Avicennia with thin pencil-like roots.

And this is the flower of one of the Bruguiera species.

Even the huts along the boardwalk is so cute, with all the collages of drawings.

And hey, we saw this monitor lizard basking under the sun. Monitor lizards are the cleaners of the shores as they can feed on almost anything they catch. They also can "smell" the air with their tongue to track down prey. In Chek Jawa, we even saw one swimming and they are known to even swim underwater for half an hour.

Here is a fly on a leaf that has gotten my attention to take a snapshot before moving on as the teaching assistant shows us the different parts of mangroves.

This is a giant mudskipper which is actually a fish that can stay on land. How do they do it? They have hold water in their mouth and also breathe through moist skin. These fearsome predators even have two rows of teeth in their upper jaw, feeding on small fishes and crabs.

Talking about crabs, we have the tree climbing crabs. Why? Because they climb on trees! Duh. They climb high up during high tide to avoid being preyed upon. These guys eat mangrove leaves and seedlings and sometimes scavenge for meat.

The furthest seaward zone is where you can find the sandbank, as shown here. You can see many herons resting and feeding on the sandbank and also have a great view of Johor from here.

A close-up of the birds on the sandbank.

We then proceeded to the bridge over Sungei Buloh Besar and this photo shows the upstream portion where nutrients input into the mangrove ecosystem. There is a big name to explain this: allochthonous nutrient input.

And downstream, we find the river leading to the Straits of Johor.

Across again, another view of Johor. Sadly, we did not see natural shores along, but with modifications.

Here again we chanced upon this resident monitor lizard at the side of Sungei Buloh Besar. It is evident that there are the pencil-like thin roots which mainly belonged to the Avicennia trees.

Archer fish is interesting because they can feed on insects near the water surface by pumping out forceful jets of water to knock insects off leaves.

Our last stop was the main hide where we were told that many telescopium Rodongs can be found on the flat when the sluice gate drains the water out.

The whole trip was summarized with a short test and we were of course stressed over it for that short moment. Other than that, was a great trip. Thank God for wonderful weather despite nasty forecast from meterological station.

No comments:

Related Posts Plugin for WordPress, Blogger...