Modern pollen-vegetation-stable carbon isotope analogues of Bakhira lake, central Ganga plain, India: implications for palaeoclimatic and palaeoecological reconstruction

A multiproxy modern surface sediments sample analogue including pollen, non-pollen palynomorphs (NPPs), Total organic carbon/Total nitrogen (TOC/TN), and stable carbon isotopes (δ 13 C values) were generated from the Bakhira Lake, Central Ganga Plain (CGP) to delineate the modern climate-vegetation relationship and human-environment interactions. Pollen data reveal a dominance of non-arboreals (67.4%) over arboreals (32.6%) along the lake margins, with increased arboreal representation (e.g. Acacia , Madhuca indica , Anacardiaceae, Trewia nudiflora , Peltophorum , Arecaceae) in the lake centre. This reflects both land-use intensity and pollen production biases. The assemblage indicates a mixed deciduous forest under warm, humid conditions. The occurrence of marker pollen taxa, such as Cerealia, Alternanthera , Asteraceae, Chenopodiaceae/Amaranthaceae (Cheno/Am), Brassicaceae and NPPs along with coprophilous fungi assemblage (viz. Sordaria , Podospora, Delitschia , and Ascodesmis ) shows the anthropogenic activities and intensively-grazed conditions over the sampling site. The relatively higher δ 13 C values (−19.7 to −21.7‰) indicate C 3 dominated to mixed C 3 −C 4 vegetation input to the sedimentary organic matter at the lake centre. The NW and SE flanks, together with cropland, have relatively lower δ 13 C values ranging from −21.2‰ to −28.9‰, except for the sample number S23 (−19.3‰), indicating a higher contribution of organic matter from C 3 vegetation. Ordination analysis of pollen taxa distributions in surface sediments samples revealed correlations among sampling locations, modern pollen deposition, and associated environmental factors. This multiproxy modern dataset provides a robust baseline for interpreting Holocene palaeoecological and palaeoclimatic dynamics across tropical lacustrine systems in the central Indian subcontinent.