1994-95 - Birbal Sahni Institute of Palaeobotany

BSIP
Pollen analysis ofa 1.8 m deep soil profile from Dewar Tal has revealed the presencc
of chirpine forests in the region around 2,500 years B.P. The broad-leaved taxa, such
as Quercus, Alnus, Rhododendron, etc. were scantily distributed around 2,000 years B.P.
The mixed Chirpine-Oak forests got established as indicated by the increased frequencies
of Quercus, Alnus, Rhododendron and shmbby elements of Strobilamhes, Oleaceae and
Rosaceae. Thereafter, the decline in these forests and simultaneous improvement in grasses
and other non-arboreals have been witnessed.
Chhaya Sharma & M.S. Chauhan
Pollen analysis of24 samples from 1.5 m deep soil profile (DT-3) from Deoria Tal,
Garhwal Himalaya has been carried out. Study reveals the dominance of non-arboreals over
arboreals. Poaceae followed by Cyperaceae are major constituents. Asteraceae,
Ranunculaceae, Cheno/Ams, Caryophyllaceae, Brassicaceae, Polygonaceae, Lantiaceae and
Urticaceae, etc. are other associates of ground cover. Arboreals are poorly represented by
Pinus, Quercus, Alnus, Bewla, Carpinus, Rhododendron, Picea, Abies, Ephedra, Ulmus,
Celtis, Juglans, Myrtaceae, Symplocos, Juniperus and Fabaceae. Fern spores are encountered
in good number reflecting their oligin from local source. The overall vegetation assemblage
depicts that around 2,500 years B.P. the open mixed broad-leaved forest existed in the
region.
Chhaya Sharma & Asha Gupta
Five aeropalynological samples from Chaurangi Khal, Garhwal Himalaya were
pollen analysed .The study reveals the dominance of ru·boreals over non-arboreals. Arboreals
show high frequency of Pinus followed by Quercus, Carpinus, Betula, Alnus, Corylus,
Ulmus, Celtis, Juglans and Rhododendron. Non-ru·boreals ru·e represented by Poaceae,
Ranunculaceae, Cyperaceae, Cheno/Ams and Brassicaceae, etc. Fungal spores ru·eencountered
in good nUI)1berwhile fern spores occur rarely. TIle composition ofaerospora more or
less colTesponds with the sUlTounding vegetation in the region, except for the under-representation
of fern spores which could be attributed to their restricted verticaltranspOltation.
Programme 7.3
History of mangrove vegetation in India
Asha Gupta & Chhaya Shru·ma
Objecti\'e
To study palynostratigraphy and Dispersed Organic· Maller
analysis of the sediments from Chilka Lake in Mahanadi­
Brahmani-Baitarini delt{/lc region in Orissa
Five samples of250 m deep profile at the depth between 51-55 m from Sadanandpur
in Mahanadi Delta have been palynologically investigated. The assemblage showed the
preponderance of Poaceae, Cyperaceae, Chenopodiaceael Amru·anthaceae, Urlicaceae, Typha,
Leollla, N)'mphoides, Potamogeton, etc. The core-mangrove taxa such as Rhizophora,
Avicennia, Excoecaria, Heritiera and pelipheral mangroves were lowly present. The palynological
;nvestigation has revealed that during this phase the sea regressed leaving the
relics of mangrove forest in Mahanadi Della.
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