FAUNA AND FLORA OF MANGROVE SWAMPS
91
B. A fresh to brackish water zone with salinities between O x ,
and lo%,.
B1. Areas more or less under the influence of the tides.
B2. Areas seasonally flooded.
It is clear that A1 and A4 are equivalent t o Watson’s classes (i) and
(v) respectively; A2 overlaps Watson’s classes (ii) and (iii) and A3
overlaps (iii) and (iv). B1 includes both barringtonia racemosa and
nypa associations and B 2 includes peat and other swamp forests and
areas dominated by Hibiscus tiliaceus L.
3. Walter and Steiner (1936) working on the mangal at Tanga in
East Africa named the zones after the dominant tree. This was followed
by Macnae and Kalk (1962) (cf. Fig. 19) and developed and extended
by Macnae (1966) in a way which may be applied in any mangrove
area (see Fig. 7 ) .
There are distinguished :
(1) The landward fringe.
(2) Zone of ceriops thickets.
(3) Zone of bruguiera forests.
(4) Zone of the rhizophora forests.
(5) The seaward avicennia zone.
(6) The sonneratia zone.
Modifications may be expected in the first three of these zones, and the
last is not present on all shores for i t is restricted t o warmer coastlines.
Watson’s figure showing the distribution of mangrove species in
Malaya (Fig. 6) clearly indicates that he appreciated that the zonation
followed this pattern.
A. The landward fringe
This zone is the most highly variable of all the zones of the mangal.
The soils may be predominantly sandy or predominantly muddy ; they
may be well drained or waterlogged ; they may be rich, derived from
recent volcanic rocks; or poor, derived from ancient granites and
quartzites ; they may be marly, derived from limestones or peaty with
much organic matter. The salinity of the soil water may be high or low.
Each of these produces some variation but in general the mangals vary
within two facies : (1) following on a forested supralittoral, and (2) following on a non-forested supralittoral, i.e. of grassland, scrub or desert.
1. Following on a forested supralittoral
Where
climax rain forest has developed, or is capable of being developed, the
The word forest is used here to include rain forest only.
91
B. A fresh to brackish water zone with salinities between O x ,
and lo%,.
B1. Areas more or less under the influence of the tides.
B2. Areas seasonally flooded.
It is clear that A1 and A4 are equivalent t o Watson’s classes (i) and
(v) respectively; A2 overlaps Watson’s classes (ii) and (iii) and A3
overlaps (iii) and (iv). B1 includes both barringtonia racemosa and
nypa associations and B 2 includes peat and other swamp forests and
areas dominated by Hibiscus tiliaceus L.
3. Walter and Steiner (1936) working on the mangal at Tanga in
East Africa named the zones after the dominant tree. This was followed
by Macnae and Kalk (1962) (cf. Fig. 19) and developed and extended
by Macnae (1966) in a way which may be applied in any mangrove
area (see Fig. 7 ) .
There are distinguished :
(1) The landward fringe.
(2) Zone of ceriops thickets.
(3) Zone of bruguiera forests.
(4) Zone of the rhizophora forests.
(5) The seaward avicennia zone.
(6) The sonneratia zone.
Modifications may be expected in the first three of these zones, and the
last is not present on all shores for i t is restricted t o warmer coastlines.
Watson’s figure showing the distribution of mangrove species in
Malaya (Fig. 6) clearly indicates that he appreciated that the zonation
followed this pattern.
A. The landward fringe
This zone is the most highly variable of all the zones of the mangal.
The soils may be predominantly sandy or predominantly muddy ; they
may be well drained or waterlogged ; they may be rich, derived from
recent volcanic rocks; or poor, derived from ancient granites and
quartzites ; they may be marly, derived from limestones or peaty with
much organic matter. The salinity of the soil water may be high or low.
Each of these produces some variation but in general the mangals vary
within two facies : (1) following on a forested supralittoral, and (2) following on a non-forested supralittoral, i.e. of grassland, scrub or desert.
1. Following on a forested supralittoral
Where
climax rain forest has developed, or is capable of being developed, the
The word forest is used here to include rain forest only.