Scientists study pollen, spores and organic matter on Indian plateau

A study by Birbal Sahni Institute of Palaeosciences (BSIP), an autonomous institute of Department of Science and Technology, suggests that despite highly devastating consequences for terrestrial faunas (dinosaurs, in particular), the Deccan Volcanism only caused regional and short-term impacts on the flora. Instead, it promoted diversification and expansion of angiosperms within diverse habitats on the Indian Plate. Conclusively, the latitudinal shifting of the Indian Plate within the Inter Tropical Convergent Zone (ITCZ), the formation of a filter corridor between Africa and India and excessive warm and humid climate during dormant phases of Deccan Volcanism instituted the rapid development and diversification rather than extinction in the tropical rainforest community.

The scientists unearthed this by studying pollen, spores and organic matter which they extracted from sedimentary rocks in living and fossil forms. Rock (mudstone and claystone) samples were collected from a 17 m thick sedimentary sequence from Yeotmal area in Maharashtra. Palynomorphs Pollen, spores (palynomorphs) and organic matter (plant debris) were extracted from samples by digesting them with different acids for palynological and palynofacies analyses (study of pollen, spores, organic matter etc in living and fossil forms). Palynology is used for establishing biostratigraphy and reconstructing palaeoecology, palaeoclimate and palaeobiogeography, while, palynofacies studies were used for reconstructing depositional environment. Palaeoecological and palaeoclimatic models based on methods called Nearest Living Relative (NLR) approach and Coexistence Approach (CA) analyses were used in the study. Palaeobiogeographic reconstruction was also undertaken.

The study published in the journal Earth Science Reviews shows that despite the fact that Deccan Volcanism released toxic greenhouse gasses into the environment, causing the K-Pg mass extinction due to rise in global temperatures, the tropical flora recovered swiftly on a sub-millennial scale, indicating higher resilience of tropical flora to climatic stresses. Therefore, understanding floral turnovers brought by geological and climatic upheavals during the geological past may aid in forecasting their responses to the ongoing climatic changes due to global warming.

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