Mangrove forests are one of the most productive habitat type in the world. They can sequester carbon, protect coastlines, and support high biodiversity. They are also widely distributed across the tropical coastlines of the world. I am sure most of us have encountered them before, but have you ever wondered what characteristics define a mangrove? Join Dr. Gretchen Coffman and my project group on the GE3255 Aquatic, Riparian and Coastal Systems field trip to Sungei Buloh Wetland Reserve as we uncover the quintessential characteristics of a mangrove!

The most ubiquitous characteristic of healthy mangroves we can see here is how shaded they are. The mangrove ecosystem here has three layers of canopy which significantly obstructs sunlight penetration. This means shaded pathways but also many epiphytes growing high up to compete for the limited light (Figure 1).

Figure 1: Photo of shaded boardwalk under dense canopy (left) and a Finlayson’s Cymbidium (Cymbidium finlaysonianum), a native epiphyte of Least Concern IUCN conservation status, growing on a tree (right). Photo credit: Ryan Chia

Another conspicuous mangrove characteristic found here is the vibrant sound of wildlife. Unsurprisingly, we can hear the familiar sound of crickets and cicadas here. However, if we listen in closely, we can also hear a myriad of bird calls. Make sure to identify them using the mobile application, BirdNET (Figure 2)!

Figure 2: Illustration of an Orange-bellied Flowerpecker (Dicaeum trigonostigma), a native bird of Least Concern IUCN conservation status, as identified from its call using BirdNET. Illustration credit: Ryan Chia

Two less noticeable mangrove characteristics are the taste and touch of mangrove leaves. Some taste salty as they excrete excess salt absorbed from the highly salinized soil. Others feel leathery as to prevent desiccation against high temperatures. Some exhibits both (Figure 3)!

Figure 3: Illustration of Api Api Putih (Avicennia alba), a native mangrove of Least Concern IUCN conservation status, that possess salt-excreting leathery leaves. Illustration credit: Ryan Chia

The last mangrove characteristic is its ‘rotten egg’ smell. Although seemingly unattractive, this smell indicates a healthy ecosystem. This is because it comes from the sulphur that is emitted from bacteria decomposing leaf litter for nutrient cycling (Figure 4).

Figure 4: Photo of leaf litter on forest floor. Photo credit: Ryan Chia

Unfortunately, these sensations are now harder to find in Singapore than ever before. This is because mangroves have been severely degraded in Singapore and the Southeast Asian region over years of urbanization. However, there is still hope as restoration projects are on the rise. Let’s all help support these noble efforts by expressing vocal support as a community or even participating in them ourselves!