Paleo-environmental and modeling insights into Mediterranean fire-vegetation interactions in response to Holocene climate and land-use changes

Our research addresses ecological and climatic questions on annual to millennial time scales. We use evidence preserved in Quaternary and modern sediments, as well as modeling approaches to study the long-term interactions among climate, the biosphere, and society in Mediterranean Italy and parts of Europe.

Our project consists of two parts: one aimed at increasing the resolution and available proxy data for existing sequences in the whole of Italy as well as the study of new sequences from Sardinia and Crete. The second part focuses on the calibration of charcoal influx into lakes across Europe, to obtain quantitative fire reconstructions especially from the Mediterranean, which is today especially threatened by fire during summer. Results from both parts will be used to refine existing dynamic vegetation models.

In the first part - the detailed investigation on new (as well as old) sedimentary sequences -, we want to produce high-resolution radiocarbon-dated pollen, spore and charcoal records also including other proxies (chironomids, diatoms, stable isotopes, etc.) in order to trace past fire activity, climatic variations, forest dynamics and land-use changes. Previous publications comprise reconstruction of several lakes, including Lago di Massaciuccoli, Lago dell'Accesa (Tuscany), Biviere di Gela, Gorgo Basso and Lago Urio Quattrocchi (Sicily), while ongoing research is focusing on Lago Baratz, Stagno di Chia and Stagno di Sa Curcurica (Sardegna, Italy) and Lake Kournas (Crete).

In the second part - the calibration of charcoal influx values -, we have distributed 40 sedimentary traps across Europe in such a way that all possible ecosystems are covered: ranging from the southern Mediterranean to the tundra in Sweden and from West to East covering a transect from Portugal into Ukraine. The countries included in our dataset are: Portugal, Spain, France, Switzerland, Italy, Germany, Poland, Czech Republic, Ukraine and Sweden.

Lake Baratz, Sardinia (Italy)
Lake Baratz, Sardinia (Italy)
Carrying our equipment in Abisko, Sweden (left); Lake Suchard II in the Wigry National Park Area, Poland (right)
Carrying our equipment in Abisko, Sweden (left); Lake Suchard II in the Wigry National Park Area, Poland (right)

The data obtained from the sedimentary traps will be compared to satellite data registering large-scale fires to obtain a statistical relationship between the observed fires and the charcoal particles found in the traps. This relationship will then be integrated in a dynamic vegetation model and applied to long vegetation sequences.

In conclusion, this project will help us to clarify how ecosystems reacted to past climate changes and fire events, and will allow us to understand local and regional present vegetation and ecosystem responses to climate change and increasing fire activity.

Funding

This project is funded by the Swiss National Science Foundation (SNF)

Participants

Internal

Paul Henne, Erika Gobet, Stéphanie Samartin, Tiziana Pedrotta, Carole Adolf and Willy Tinner

External

Harald Bugmann and Che Elkin (ETH Zürich), Massimo D'Angelo (Ente Foreste della Sardegna, Sassari), Tommaso La Mantia and Salvatore Pasta (University of Palermo), Aldo Marchetto (CNR Verbania-Pallanza), Boris Vannière (CNRS France), Flavio Anselmetti and Stefan Wunderle (University of Bern)