Chapter 2 Mangrove Forests
Chapter 2
Mangrove Forests
In this lesson, you will understand:
• Where are Mangrove Forests found?• What general characteristics do MF have?• What special adaptations do MF have?
Distribution of Mangrove Forests
• Places that experience tropical climate i.e. between 23.5ºN & S of Equator
• especially along sheltered coastal regions and where rivers deposit clay and silt
Diversity of Mangrove Forests
• Halophytes (salt-tolerant plants) commonly found– e.g. avicennia, sonneratia, rhizophora, bruguiera– other plant species e.g. sea hibiscus, nipah palm
Density of Mangrove Forests
• High density due to high temperature & rainfall• Sparse undergrowth due to dense canopy
Structure of Mangrove Forests
• 3 horizontal zones with trees about 15m tall• Trees vary in height from 2m – 40m as muddy soil
in environment cannot provide firm support
High tideLow tide
Coastal zoneCoastal zone Middle zoneMiddle zone Inland zoneInland zone
Coastal Zone in Mangrove Forests
• Nearest to sea, flooded with saltwater at high tides• Trees have tube-like breathing roots • e.g. avicennia species (pencil shaped)• e.g. sonneratia species (peg shaped)
Middle Zone in Mangrove Forests
• Trees have prop or stilt roots growing from trunks for anchoring plants firm to muddy soil
• e.g. rhizophora species
Inland Zone in Mangrove Forests
• Trees have knee-like roots to provide support on soft soil
• e.g. bruguiera species that are least salt-tolerant
MF Special Characteristics: Leaves
• Evergreen, thick & leathery, broad with drip tips
• Avicennia species are salt secretors– excess salt secreted on leaves
and removed by wind or rain• Bruguiera, Rhizophora and
Sonneratia species are ultrafiltrators– excess salt stored in old leaves
which then fall off
MF Special Characteristics: Flowers and Fruits
• Generally colourful flowers to attract insects for pollination– e.g. Bruguiera species has
bright-red lantern flowers• Buoyant fruits that are
dispersed by water• Elongated fruits which
germinate while on parent tree– e.g. Rhizophora species
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In this lesson, you have understood:
• Where are Mangrove Forests found?• What general characteristics do MF have?• What special adaptations do MF have?