CONTENTS
Flora index
Fauna index
guide to the mangroves of singapore
The Ecosystem: Abiotic components
Peter K L Ng and N Sivasothi (editors)
 
Soil

Mangrove soils in Singapore are of recent marine alluvium, transported as sediment and deposited by rivers and the sea, which have been classified by geographers as the 'Kranji series'. Soils are made up of sand, silt and clay in different combinations, and 'mud' actually refers to a mixture of silt and clay, both of which are rich in organic matter (detritus).
Mangrove Ecosystem
Abiotic components
Soil
pH
Oxygen
Nutrients
Winds and currents
Light, temperature, humidity
Tides
Salinity

Biotic components
Vegetation
Zonation
panoramic view of mudflat
Clayey-type topsoil Sungai Mandai
Besar mangroves
What we see on the surface is topsoil, and are loosely recognised as sandy or clayey types. The lighter-coloured sandy topsoils are porous and facilitate water percolation and aeration during low tide. The darker-coloured clayey topsoils, however, are less well aerated.
Localised variation can be further caused by burrowing animals like the Mud lobster or Fiddler crabs.
Soils below the surface (subsoils) are typically waterlogged, have little aeration which decreases with depth and contain a lot of organic matter decomposing at a very slow rate.
panoramic view of sandy mangroves
Sandy-type topsoil Sungai Mandai
Besar mangroves
"How do I avoid sinking in the mud?"
Look for sand! Or make your way to tree roots or pneumatophores. Spread over a wide area, roots offer good support to both the tree and yourself! In a stream, walk in its centre - the coarser, heavier material such as sand and pebbles found there provide relatively firm support.
The dark grey or black soil which produces a strong odour when unearthed indicates the presence of hydrogen sulphide, the result of anaerobic sulphur-reducing bacteria (e.g. Desuifovibrio sp.) which thrive in the anoxic condition.
Soil condition is one of the contributing factors of zonation among animals and plants, e.g., different species of Fiddler crabs thrive in different soil conditions, and while plants like Avicennia and Sonneratia do well in sandy areas, Rhizophora copes better with soft hurnus-rich mud while Bruguiera favours stiff clay containing little organic matter.
What is mangrove?
Introduction

The Ecosystem

Abiotic
Biotic

Value
Intro
Products
Indirect uses
Potential uses

About Mangroves
in Singapore

History
Mangroves to visit
Conservation
 
From "A Guide to Mangroves of Singapore", Peter K. L. Ng and N. Sivasothi (editors)
Volume 1: The Ecosystem and Plant Diversity and Volume 2: Animal Diversity
Authors: Kelvin K. P. Lim, Dennis H. Murphy, T. Morgany, N. Sivasothi, Peter K. L. Ng,
B. C. Soong, Hugh T. W. Tan, K. S. Tan & T. K. Tan
BP Guide to Nature Series published by the Singapore Science Centre, sponsored by British Petroleum
2001 Raffles Museum of Biodiversity Research, The National University of Singapore & The Singapore Science Centre