Partners:
- CNR-ISP: Institute of Polar Sciences, Venice
- DST-UNIPI: Department of Earth Sciences, University of Pisa
Duration: 1/12/2023 – 28/02/2026
Budget (€): 237.220,00
ERC field: PE - Physical Sciences and Engineering
ERC subfields: PE10_11 Geochemistry, cosmochemistry, crystalchemistry, isotope geochemistry, thermodynamics; PE4_5 Analytical chemistry; PE10_6 Palaeoclimatology, palaeoecology
Keywords: speleothems; paleofire; stable isotopes; Holocene; caves; Italy
Scope – Develop a new method to Reconstruct the Holocene variability of wildfire across the Mediterranean region.
Fire, a major driver of environmental change, is likely to become a more frequent occurrence in Southern Europe as a result of climate change. Understanding the complexities involved in fire-ecosystem-climate feedbacks benefits from a knowledge of past fire dynamics, particularly during intervals of distinct human activity and/or climatic conditions. Thanks to their continuous growth and precise dating, speleothems are widely used in paleoclimate reconstructions and can provide high resolution climate information. Recently, successful attempts of reconstructing paleofire activity from stalagmites through trace elements and levoglucosan were proposed, demonstrating the large and still widely unexplored potential of speleothems for multi-proxy studies and novel fields of paleoresearch.
PROMETHEUS aims at testing the possibility for Italian speleothems to be used as high resolution paleofire archives through a pioneering approach employing organic molecular proxies. Namely, it plans to determine the abundances and distributions of 19 polycyclic aromatic hydrocarbons (PAHs) and 26 linear aliphatic hydrocarbons (n-alkanes) in Holocenic speleothems from five cave sites located in different contexts in terms of climate, geographic location, and speleological features. The suitability of sites will be first evaluated through preliminary analyses to select the working set of speleothems for high resolution reconstruction.
A wide range of PAHs are produced by biomass burning, and the resulting distribution can be associated to combustion conditions, while n-alkanes are among the main components of plant epicuticular waxes and can thus be reconducted to the composition of vegetation. Target compounds, characterized by high stability and persistence in the environment, are deposited onto soil, carried downward by infiltrating water, and incorporated into speleothems where they can be retrieved and used as paleofire proxies.
The main goal of PROMETHEUS is to obtain the first high resolution Italian paleofire record from speleothems, integrating multiple linear and polycyclic hydrocarbon records with δ18O-δ13C time series, in order to interpret the fire signal and the vegetation record together with climate information, and to identify environmental and climatic drivers of change in fire regimes in each specific context. In addition, the comparison with existing paleofire sedimentary records from Italian lakes where shifts in fire regimes were previously identified and, for modern ages, with registry and satellite-derived fire occurrence data, will allow data calibration and contextualization in temperate climates, where this approach is unprecedented.
Other UniPisa participants: Giovanni Zanchetta.