Hydroclimatic changes in the Core Monsoon Zone of India since the Last Glacial Maximum: An overview of the palynological data and correlation with the marine and continental records

Vegetation diversity in response to monsoonal variability in the Eastern Himalaya, India over the past ~13 000 yrs

“…Climatic amelioration (increased Monsoon) during the last 1.0 ka (coincided with the MCA) are recorded in Spiti, Himachal Pradesh (Chauhan et al, 2000), Dokriani valley (Phadtare, 2000), and Bedni, Garhwal Himalaya (Rawat et al, 2021). Moreover, the MCA has been also observed in other paleoclimate records from the Himalayas (Bali et al, 2015, 2017; Dutt et al, 2021; Ghosh et al, 2018; Kar et al, 2002; Quamar, 2020; Sharma and Chauhan, 2001; Singh et al, 2020; Figure 9), central India (Chauhan and Quamar, 2010; Quamar, 2022; Quamar et al, 2024; Quamar and Bera, 2021; Quamar and Chauhan, 2014; Sinha et al, 2007, 2011,), the Ganga Basin (Singh et al, 2015), Northeast India (Tripathi et al, 2020), Peninsular India (Reddy A et al, 2022), Western India (Quamar et al, 2023a; Sodhi et al, 2022), the BoB (Naidu et al, 2020) and western Arabian Sea (Gupta et al, 2005). Moreover, from Basomtso Lake in the southeastern Tibetan Plateau, warmer climatic conditions and increased glacial meltwater input were suggested between CE 1080 and CE 1140, corresponding well with the MCA (Li et al, 2016).…”

“…The signatures of HCO are also recorded from northeast India (Dixit and Bera, 2013) and also from the tropical regions of central India (Chauhan, 2015; Chauhan and Quamar, 2012; Quamar, 2022; Quamar et al, 2024; Quamar and Bera, 2017; Quamar and Chauhan, 2012; Quamar and Kar, 2020 and references cited therein). A coherence in summer monsoon strength during the HCO accords well with other records of the BoB precipitation (Contreras-Rosales et al, 2014) and high-resolution spelaeothem δ 18 O record of the south-eastern Tibetan Plateau (Dykoski et al, 2005).…”

“…The regional ISM data (Herzschuh et al, 2006) also suggests moderate hydroclimatic conditions during the mid-Holocene for which stable sea surface temperature of the Bay of Bengal attributed to a more or less stable north Atlantic climate is implicated (Gupta et al, 2003; Liu et al, 2021; Stuiver et al, 1997; Figure 10). Till date, the studies have demonstrated that HCO was asynchronous with inconsistencies in magnitude and duration which can be partly explained by varying resolutions, age uncertainties and differential proxy response (Ghosh et al, 2023; Quamar et al (2023b, (2024 and references cited therein). This warming, although asynchronous, is commonly associated with the orbitally forced summer insolation maximum (Bartlein et al, 2011; Wanner et al, 2008).…”

“…Fossil pollen records have been the major source for understanding the past vegetation composition, vegetation based climatic reconstructions and the commencement of anthropogenic influence (Birks, 2019; Cao et al, 2013; Chevalier et al, 2020; Grindean et al, 2015; Kar and Quamar, 2019; Quamar, 2022, 2023a, 2024 and references cited therein). However, with respect to the Indian Himalayan region the pollen based studies have predominantly focussed on reconstructing past climatic variability (Ali et al, 2020; Arora et al, 2023; Quamar and Kar, 2020).…”

Multiproxy studies on the spatially distinct surface samples to reconstruct palaeoecology and palaeoclimate from the Core Monsoon Zone of India

“…The distribution pattern of vegetation is strongly dependent on the climatic conditions (precipitation, temperature), soil characteristic and altitude, as well as on human impact (Chen et al, 2006;Faegri & Iversen, 1964;Gasse et al, 1991;Ivanov et al, 2007;Kar et al, 2022;Kar & Quamar, 2019;Mishra et al, 2022;Quamar & Kar, 2020b;Sun & Wu, 1987 and references cited therein). Moreover, characterising pollen, which is produced by the vegetation itself, and its spatial distribution in a geological past regarding the existing vegetation structure of an area is crucial for understanding past climatic changes (Birks & Birks, 1980Gaillard et al, 1992;Gosling et al, 2005;Jackson & Williams, 2004;Kar & Quamar, 2019;Mohanty et al, 2024;Quamar, 2020;Quamar & Kar, 2020a;Quamar et al, 2023Quamar et al, , 2024Traverse, 1988 and references cited therein). Rational knowledge and understanding of modern pollen-vegetation relationship is, moreover, imperative and prerequisite for the reconstruction of past vegetation and climate change through studying the fossil pollen records (Bradshaw & Webb, 1985;Birks & Berglund, 2018;Faegri & Iversen, 1989;Jackson, 1994).…”