Maria - Antonia SERGE

Thesis title: REVENGE – Quantitative REconstruction of Natural and anthropogenic VEGetation cover at the European scale and over the Holocene.

• Supervisor: Didier Galop
• Co‑supervisor: Florence Mazier (florence.mazier@univ-tlse2.fr);
• Scientific support: Ralph Fyfe (ralph.fyfe@plymouth.ac.uk)
• Keywords: Pollen modelling, quantification and spatialisation of palaeovegetation, palaeolandscape reconstructions, European scale, Holocene

 

Context of the PhD project:

Landscapes provide multiple ecosystem services, both in terms of natural resources (water, food, energy, etc.) and in cultural, scientific, sociological and touristic terms.. Despite their importance, many landscapes are currently threatened by deforestation, degradation, uncontrolled urbanisation and global change induced by humans.

European societies have exploited and managed their landscapes for millennia, but recent and rapid socio‑economic change, together with strong societal demands regarding the environment, have become a challenge for decision‑makers.

Recent climatic and anthropogenic changes have been recognised as one of the greatest threats to ecosystem services and human well‑being..Managers are also confronted with many challenges, such as the ecological and energy transition towards a low‑carbon society with less air pollution. They now need an in‑depth understanding of the physical, social and cultural characteristics of the landscapes for which they are responsible.

The ERC ITN TERRANOVA project aims to train 15 PhD students (early stage researchers, ESRs), working in close collaboration with decision‑makers.

The mission of TerraNova is to develop an unprecedented digital atlas of Europe compiled by an interdisciplinary group of researchers combining models of past human populations, plants and disturbances, animal development and climate change.

At the heart of national and international scientific debates, questions of energy regimes and transitions (hunter‑gatherers, agricultural revolution, agriculture/forestry, etc.) and those concerning the sustainable management and conservation of landscapes require a better understanding of the forcing factors behind these landscapes, whether climatic and/or anthropogenic.
These questions require, among other things, deepening research at different spatio‑temporal scales on the genesis, maintenance and evolution of ancient landscapes, and analysing their capacity to respond to socio‑environmental and energy changes. However, scientific knowledge in this field is still scarce, and most research relies on short‑term data, at most from the last fifty years.
Thus, in response to this issue, palynology, the study of pollen grains and spores, through retro‑observation methods, is legitimately positioned as one of the main methods capable of providing continuous diachronic data with multi‑century hindsight to answer certain questions raised by conservation biology. 

The main criticisms made by ecologists and conservationists towards palynologists concern the lack of spatio‑temporal resolution of pollen data, and in particular the difficulty of quantifying and spatialising pollen information to access information on the spatial structure of vegetation over the long term.

PhD project:

In this context, this PhD project focuses mainly on the floristic diversity of vascular plants (species, genera or families) and landscape units (i.e. broadleaves, conifers, crops, grasslands, etc.) and is based on a retro‑observation of European landscapes founded on a resolutely interdisciplinary approach combining palaeoecology, vegetation modelling and geography.
Its aim is to generate maps of vegetation cover and land use at the European scale that will make it possible to assess the degree of openness and exploitation of the landscape between and during energy transitions. Four energy regimes (ER) and three transitions (TR) will be addressed (ER1 Hunter/Gatherers, T1 Agricultural Revolution, ER2 Agricultural/Timber, T2 Industrial Revolution, ER3 Industrial/Coal/Oil, T3 Green Transition, ER4 Low Carbon Society).

The objective of ESR6 is an explicit description of past natural and anthropogenic vegetation cover at the European regional scale, presenting pollen‑based estimates of vegetation cover in Europe during the Holocene using the REVEALS model (Sugita 2007), to improve our understanding of landscape and land‑use histories in Europe during the Holocene in order to assess the effects of future climate and land‑use changes on European ecosystems, landscapes and biodiversity during three energy regimes and transitions.

The new reconstruction improves the spatial coverage of the first and second generation of REVEALS reconstructions with 500 additional pollen records (particularly from the Mediterranean area: Italy, Spain, Portugal), for a total of 1600 sites used for the whole of Europe, obtained from authors and databases (European Pollen Database, Neotoma, Pangea). She arranged and cleaned the data and prepared them for inclusion in the REVEALS model.
Regional vegetation abundance is estimated using three alternative datasets of relative pollen productivities (RPP) for a total of 46 taxa at a spatial resolution of 1°×1° (approximately 100 km × 100 km) for consecutive time windows over the last 11.7 ka BP.

The objective of this first article is to test three different RPP datasets to understand the sensitivity of the model (REVEALS) and how these estimates affect the results.

The initial work of ESR6 will contribute to the Atlas with vegetation maps (and metadata in appendix) covering the whole of Europe and the entire Holocene. Moreover, thanks to these results, it will be possible to collaborate with other early‑career researchers, contribute to the writing of other articles, deepen knowledge of the period and achieve the required deliverables.

She will explore the results obtained in the previous work, for the second article, in order to analyse regional anthropogenic vegetation cover throughout the Holocene, attempting to understand the general trends of regional vegetation abundance estimated by REVEALS in Europe in space and time and how humans influenced past landscapes at the regional scale during the three past energy regimes and their two transitions, and the magnitude of Holocene‑described deforestation.

The short stay at the University of Plymouth (United Kingdom) enabled the learning of the vegetation reconstruction model from a technical perspective, and the secondment carried out at Linnaeus University (Sweden) supported ESR6 in understanding her scientific questions.

Abstracts :

• SERGE M.A., RAVAZZI C., FURLANETTO G., GAROZZO L., VALLÈ F., DE NASCIMENTO L., NARANJO-CIGALA A., DAINA P., VALOTI F., FERNÁNDEZ-PALACIOS J.-M. (2018). Building up a pollen- vegetation-climate-environment training set from Gran Canaria as a tool for palaeoenvironment and palaeoclimate reconstructions. 10th EPPC, session 27 – Work vertically, think 3-dimensionally: palaeoecology in topographically complex mountain settings.
   
• SERGE M.A, FURLANETTO G., RAVAZZI C., BADINO F., BRUNETTI M., CHAMPVILLAIR E., MAGGI V. (2018). Developing altitudinal training sets of pollen rain-site specific temperatures in the Alps as a base for paleoclimate reconstructions of high-altitude fossil records. 10th EPPC, session 27 – Work vertically, think 3- dimensionally: palaeoecology in topographically complex mountain settings.

Publications :

• Anastasia Nikulina, Katharine MacDonald, Fulco Scherjon, Elena Pearce, Marco Davoli, Jens-Christian Svenning, Emily Vella, Marie-José Gaillard, Anhelina Zapolska, Frank Arthur, Alexandre Martinez, Kailin Hatlestad, Florence Mazier, Maria Antonia Serge, Karl-Johan Lindholm, Ralph Fyfe, Hans Renssen, Didier Roche, Sjoerd Kluiving, Wil Roebroeks (in prep.). Tracking hunter-gatherer impact on interglacial vegetation in Last Interglacial and Holocene Europe: challenges and proxies.

University curriculum:

• Master’s degree in Natural Sciences in 2018 at the University of Milan, Faculty of Mathematical, Physical and Natural Sciences. The thesis title is: Building a pollen‑vegetation‑climate‑environment training set from Gran Canaria as a tool for palaeoenvironmental and palaeoclimatic reconstructions. The thesis (numerical analysis) was carried out at the Laboratory of Palynology and Palaeoecology of CNR‑IDPA, Milan (Italy).The Academy of Sciences and Letters of the Lombard Institute, on the proposal of a special jury, awarded the “Fondazione Grazioli Prize 2018” to the thesis. The thesis was presented as a poster at the 10th EPPC in Dublin (August 2018), session 27 – Work vertically, think 3‑dimensionally: palaeoecology in topographically complex mountain settings.
• The PhD project began on 1 October 2019 at Université de Toulouse Jean Jaurès, in the GEODE Laboratory, supervised by Dott. Florence Mazier.