Résumé
Italy’s Holocene climate can be characterised by a latitudinal division with a climatic contrast between the northern and southern regions, notably characterised by a stronger winter–summer precipitation seasonality in southern regions. The latitudinal boundary is located between latitudes 40°and 43°N, creating a climatic transition zone. However, the mechanisms underpinning this hydro-climatic partition remain poorly understood, due in part to a scarcity of precisely dated, high-resolution records at key latitudes. Lago Grande di Monticchio ( 41°N) lies within this critical transitional band and presents a valuable opportunity to refine the latitudinal boundary location. Lago Grande di Monticchio is one of southern Italy’s most comprehensively studied sediment archives, stretching back to the last interglacial. In this study, we employ a novel, high-resolution sediment core from Monticchio, applying a multi-proxy methodology that combines branched glycerol dialkyl glycerol tetraether (brGDGT) and pollen data to reconstruct seasonal temperature and precipitation changes during the Holocene. Results confirm that temperature reconstructions derived from brGDGT and pollen records are particularly consistent for most of the signal. Comparison with other palaeoclimate records and proxies in Italy allowed us to place Lago Grande di Monticchio’s climate signal within southern climate regimes (i.e., summer cooling and aridity in contrast to wetter and warmer winters), corresponding to a stronger ”Mediterraneanization” process throughout the Holocene. Multi-proxy comparison indicates that the most marked contrast during summer likely lies near the upper bound of 41°–43°N. Persistent inconsistencies in the transition zone suggest added climatic complexity around 43°N, involving ocean-atmospheric teleconnections and local topography. We advocate further high-resolution, multi-proxy palaeoenvironmental studies in this transitional latitude band to refine understanding of the north–south hydro-climatic boundary across Italy in the Holocene.