Potential to reconstruct paleoenvironmental changes using lake sediments from Lago della Maddalena, northern Maritime Alps

High-mountain regions are highly sensitive to climate change, but there is limited understanding on how landscapes will respond to climate and land-use change, e.g., land abandonment due to rural-urban migration. In our study, we explore the potential of using lake sediments of Lago della Maddalena to serve as a high-resolution archive of Late Holocene paleoenvironmental changes. The study site is located at ~1974 m a.s.l. in the northern Maritime Alps (Italy), a climatically sensitive transition zone between Mediterranean and continental influences. The lake provides a valuable sedimentary record for identifying naturally and anthropogenically induced environmental dynamics in grazing-induced treeline settings. We aim to identify distinct sedimentary environments, material sources, and underlying patterns.

A multi-proxy approach was applied to two short sediment cores using visual lithofacies descriptions, C/N, macrocharcoal analysis, and micro-XRF core scanning. Principal component and cluster analyses of centered log-ratio transformed XRF data revealed four distinct geochemical units, indicating shifts in sediment provenance and depositional processes. The sediment composition suggests alternating phases of increased clastic input and carbonate-rich conditions. C/N ratio points to a predominance of terrestrial organic matter. Low charcoal content suggests that fire plays a minor role in the catchment area.

We discuss challenges of disentangling proxy data from broader paleoenvironmental signals, especially in contexts where climate, land-use, and geological processes interact. This work provides a methodological basis for future studies seeking to better resolve the timing and drivers of ongoing environmental change in the southwestern Alps.