Annual Report 2011-2012 - Birbal Sahni Institute of Palaeobotany

EBIRBAL SAHNI INSTITUT
1946
OF PALAEOBOTANY
Annual Report 2011-2012
The surface sediments from 17 stations in the
Vembanad Estuary have been carried out for accessing
the variation in the palynofacies assemblage. Various types
of organic matter constituents were characterized. The
study shows that the terrestrial organic matter content
was higher as compared to marine organic matter. The
different stations showed varying frequencies of
palynofacies components. The study indicates that owing
to variable carrying capacity of streams, differential runoff
conditions, the rate of sediment influx during the
monsoonal times, salinity changes, display differential
productivity signals in these stations. These studies will
be applied in down core sediment study from the adjoining
region.
Biswajeet Thakur, Vandana Prasad & Rahul Garg
(superannuated w.e.f. 30.11.2010)
The field work has been carried out in the Kerala
off shore region in the cruise SSK-15 in collaboration with
NIO, Goa, from the latitudes 7°52.5703" to 9°58.8664"
and longitudes 75°15.6372" to 76°56.6595". In the cruise
three transects are made and 38 stations are covered
and 34 Spade cores (SC) are collected. The length of the
spade cores varies from 7 to 40 cms.
Vandana Prasad
Project 9.4:
Studies on Quaternary vegetation and climate change in southwestern Madhya Pradesh,
based on pollen proxy evidence
Accomplished pollen analysis of 14 surface samples
from Badwani and Pokharni, Harda district, which has
revealed the dominance of non-arboreals over the
arboreals. Among the trees, Madhuca indica emerges
to be the prominent element as marked by its consistently
high values followed by Terminalia, Holoptelea, Sterculia
urens, Symplocos, etc. in variable frequencies. The
sporadic presence of other trees, viz. Adina cordifolia,
Lannea coromandelica, Emblica officinalis, Tectona
grandis, Acacia sp., etc. is ascribed to their low pollen
production owing to entomophilous mode of pollination as
well as relatively less frequent presence in the forest
floristic. Poaceae, Cheno/Am, Tubuliflorae and sedges
are the major non-arboreals. The representation of these
taxa corresponds with their occurrence in the ground flora.
Fungal spores, viz. Nigrospora, Microthyrium and
Glomus are also recorded frequently.
Pollen analysed a 1.5 m deep sediment profile from
Badwani, Harda district. All the samples have exhibited
poor pollen assemblage. The recovered taxa comprise a
few trees such as Madhuca indica Syzygium,
Holopletea, Acacia, etc. in extremely low values,
whereas the herbaceous elements, viz. Poaceae, Cheno/
Am, Cayophyllaceae, Asteraceae, Cyperaceae, etc. are
also met with in moderate frequencies. The overall
vegetation composition infers the presence of open
vegetation in the area during the course of sediment
accumulation. Radiocarbon dates for the profile are
awaited.
M.S. Chauhan & Anjali Trivedi
Finalized a paper entitled Mid-Holocene
vegetation vis-à-vis climate change in southwestern
Madhya Pradesh, India. The pollen sequence deciphers
that between 6,000 and 5,409 yrs BP open mixed
deciduous forests comprising Lannea coromandelica,
Terminalia, Madhuca indica, Syzygium, etc. occurred
in the region under a warm and less-humid climate, which
got transformed into dense mixed moist deciduous forests
between 5,409 and 4,011 yrs BP with the initiation of to a
warm and humid climate. The mixed forests turned less
diversified around 4,011 to 2,178 yrs BP due to prevalence
of a warm and less-humid climate again. Since 2,178 yrs
BP onwards, the enrichment of forests reflects a warm
and more-humid climate.
Accomplished another paper entitled Pollen rain
deposition pattern in tropical deciduous Sal (Shorea
robusta Gaertn.) Forests in Shahdol District,
southeastern Madhya Pradesh, India, based on the
analysis of 6 surface samples from Khanaudi Village,
Shahdol district. The study has revealed the relatively
lower frequencies of arboreals in contrast to nonarboreals.
Shorea robusta, a dominant forest element, is
recorded with av. 2% pollen only. The underrepresentation
of Shorea robusta, despite being a high
pollen producer, could be attributed to poor preservation
of its pollen. Other trees viz., Terminalia, Lagerstroemia,
Emblica officinalis, Syzygium, Sterculia, etc., despite
occurring appreciably in the forest, are sporadic owing to
their low pollen productivity. Grasses, sedges, Tubuliflorae,
Cheno/Am, etc. are the major non-arboreals,
corresponding with their composition in the ground flora.
The consistent presence of Cerealia pollen indicates the
proximity of human habitation.
M.S. Chauhan & Md. Firoze Quamar
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