FAUNA AND FLORA O F MANGROVE SWAMPS
85
and the western Pacific Ocean very suitable for the establishment of
mangroves and mangrove swamps.
The geological history of the mangroves is also quite a long one.
Muller (1961, 1964) has shown from a study of cores taken in peat
swamp and mangrove forests in Borneo that nypa pollen and a
Brownlowia-type pollen were already common a t the beginning of the
Eocene ; that pollen of the Rhizophoraceae appeared late in the Eocene
or early in the Oligocene; that pollen resembling that of Sonneratia
caseolaris (L.) Engl. appeared early in the Miocene, and pollen
resembling that of S. alba B1. late in the Miocene; and finally that
pollen of an avicennia type appeared in the mid-Miocene. These cores
were also of interest, in that they showed the presence of pollen similar
to that of Aegialitis and Camptosternon, two mangrove genera no longer
growing in Borneo, both now being restricted to more eastern areas
in the Molluccas, New Guinea etc.
Muller also quotes the following facts about the geological history
of mangroves and other associated plants. The fruits of Nypa have
been described from the London Clay flora (Eocene) of England
(Chandler, 1951) and equivalent deposits in Belgium. Pollen of rhizophora-type has been reported from the Oligocene onwards from
Venezuela, Nigeria and New Guinea (Kuyl et al., 1955). Chandler (1951)
reports fruits resembling those of Rhizophoraceae from the London
Clay. Wood and flowers resembling those of Sonneratiu have been
found in India-wood from Pliocene and flowers from Deccan Intertrappean beds attributed to Eocene (Mahabale and Deshpande, 1959 ;
Prakash, 1960).
D. Sea-shore plant associations
Leaving aside the algal associations which occur on rocky shores,
characteristic associations, principally of higher plants, grow on the
different types of non-rocky substrata which occur along shores of the
Indian and west Pacific Oceans. Schimper (1891) recognized four
associations.
(a) The Mangal-forests growing below high tide mark, and
comprising several species of trees and a few of non-woody
herbaceous plants.
(b) The Nypa Association-occurring to landward and upstream of
a mangal, dominated by the rhizomatous palm, Nypa fruticans
Wurmb., and supporting a few isolated trees, chiefly Heritiera
littoralis (L.) Dryand. and Excoecaria agallocha L., a few shrubs,
lianes and ferns chiefly Acrostichum aureum L. (Fig. 3).
85
and the western Pacific Ocean very suitable for the establishment of
mangroves and mangrove swamps.
The geological history of the mangroves is also quite a long one.
Muller (1961, 1964) has shown from a study of cores taken in peat
swamp and mangrove forests in Borneo that nypa pollen and a
Brownlowia-type pollen were already common a t the beginning of the
Eocene ; that pollen of the Rhizophoraceae appeared late in the Eocene
or early in the Oligocene; that pollen resembling that of Sonneratia
caseolaris (L.) Engl. appeared early in the Miocene, and pollen
resembling that of S. alba B1. late in the Miocene; and finally that
pollen of an avicennia type appeared in the mid-Miocene. These cores
were also of interest, in that they showed the presence of pollen similar
to that of Aegialitis and Camptosternon, two mangrove genera no longer
growing in Borneo, both now being restricted to more eastern areas
in the Molluccas, New Guinea etc.
Muller also quotes the following facts about the geological history
of mangroves and other associated plants. The fruits of Nypa have
been described from the London Clay flora (Eocene) of England
(Chandler, 1951) and equivalent deposits in Belgium. Pollen of rhizophora-type has been reported from the Oligocene onwards from
Venezuela, Nigeria and New Guinea (Kuyl et al., 1955). Chandler (1951)
reports fruits resembling those of Rhizophoraceae from the London
Clay. Wood and flowers resembling those of Sonneratiu have been
found in India-wood from Pliocene and flowers from Deccan Intertrappean beds attributed to Eocene (Mahabale and Deshpande, 1959 ;
Prakash, 1960).
D. Sea-shore plant associations
Leaving aside the algal associations which occur on rocky shores,
characteristic associations, principally of higher plants, grow on the
different types of non-rocky substrata which occur along shores of the
Indian and west Pacific Oceans. Schimper (1891) recognized four
associations.
(a) The Mangal-forests growing below high tide mark, and
comprising several species of trees and a few of non-woody
herbaceous plants.
(b) The Nypa Association-occurring to landward and upstream of
a mangal, dominated by the rhizomatous palm, Nypa fruticans
Wurmb., and supporting a few isolated trees, chiefly Heritiera
littoralis (L.) Dryand. and Excoecaria agallocha L., a few shrubs,
lianes and ferns chiefly Acrostichum aureum L. (Fig. 3).