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.