how plants cope in the mangroves: vivipary

CONTENTS

Fauna index

How plants cope in the mangroves

Peter K L Ng and N Sivasothi (editors)

Vivipary

Vivipary is the condition whereby the embryo (the young plant within the seed) grows first to break through the seed coat then out of the fruit wall while still attached to the parent plant. This condition is found in Bruguiera, Ceriops, Kandelia and Rhizophora species.

Cryptovivipary (Greek kryptos, hidden) refers to the condition whereby the embryo grows to break through the seed coat but not the fruit wall before it splits open. This condition is exhibited by Aegiceras, Avicennia and Nypa species.

There is intense speculation as to why so many mangrove species demonstrate vivipary or cryptovivipary with morphological, ecological and physiological explanations put forward.

Vivipary in
Bruguiera cylindrica

Cryptovivipary in
Aegiceras corniculatum

Difficulties arise from the fact that the mangrove environment, although unique, is so only by a set of factors and not just one. Vivipary or cryptovivipary is not found in any halophytes (plants which grow in saline environments) or freshwater swamp forest species so indicating that these conditions do not arise from salinity or wet soil conditions.

One suggestion has been that the mangrove presents relatively unstable conditions so having propagules which can grow practically immediately is an advantage. For instance, it is easy to observe that the seedlings of Rhizophoraceae can often plant themselves directly below the parent tree because the centre of gravity is close to the root tip. However, this is of little advantage to the plant in the long run as the seedlings would be competing with the parent tree for light, nutrients, etc., to their mutual disadvantage. Most such seedlings do not plant themselves, but float away and can tolerate immersion for weeks. However, on landing on a suitable substrate, the seedlings can firmly root themselves within days and grow rapidly.

Other adaptations to cope in mangroves
Salt secretors and ultrafiltrators
Breathing roots

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