Thanks to Jules Ducept from the featured image (CC BY SA 4.0, 2018)
Projects
Global Paleofire Database
In 2019 and 2020 I got involved with the Global Paleofire Working Group. Within this group, I explored the records of the Global Paleofire Database. This is a database of (paleo-)records of fire events from the entire globe.
Is present fire regime unusual in context of the Holocene and represents a risk for societies?
That’s the question we tried to answer during a workshop in July 2019 in Besançon. From the explorations we came to during the workshop, I produced regional and global syntheses of past fire events, thanks to the paleofire R package.
I worked in closed collaboration with colleagues from the group, and especially with Boris Vannière, Anne-Laure Daniau, Florent Mouillot, Daniele Colombaroli, and Olivier Blarquez.
Thanks to @raquelraclette for the background of the featured image.
Beyond Lake Villages
Climate Change in the Alps
Project’s storyline
The Climate Change in the Alps project started in 2010. It lied on the extensive archaeological surveys initiated by Thomas Reitmaier (University of Zürich) in the Central Alps, and specially in the Silvretta Massif. There, hundreds of archaeological sites, ranging from the Mesolithic Period to the Medieval Period, were identified.
The project aimed at bringing together archaeological and palaeo-ecological data. The expectations were that the latter would provide more insights about the past human activities and climatic impact on the massif’s vegetation. It consisted in an international and interdisciplinary collaboration: archaeology, landscape archaeology, etymology, palynology, carpology, dendrochronology, pedology; from Switzerland, Germany, and Austria.
I dealt with the palaeo-ecological analyses. They formed my PhD research, and dissertation, which I successfully defended in September 2015. 😎 I found that, at high altitudes in the Silvretta Massif, pastoral activities mostly began somewhere around the transition from the Neolithic Period to the Bronze Age. In other words, the neolithisation – the shift from an economy based on hunting and gathering, to an economy based on farming – happened at the really end of the Neolithic in this part of the Central Alps.
Outcome of the project
Peer-reviewed publications
Click on the preview to open the article page on the journal’s website.
The first paper published from the project in 2014 in Quaternary International revealed the vegetation composition evolution for almost the entire Holocene from the Las Gondas Bog, on the northern side of the Silvretta Massif, under climatic and anthropogenic constraints.
The second paper, published in 2015 in Zeitschrift für Geomorphologie, was a big deal at comparing all our data: palaeo-ecological, pedological, and archaeological data.
The third paper was published in 2017 in The Holocene. It deals with changes in vegetation composition, but also emphasizes the use of fire and agro-pastoral activities on the less elevated slopes of the southern side of the Silvretta Massif, using cross-correlation analysis.
The last paper, published in 2020 in The Holocene (again), deals with pastoral activities at high altitude in the Massif. The palaeo-ecological data from the small Plan da Mattun Bog – a few meters from an abri used since the Mesolithic Period – notably record an important signal from coprophilous fungi spores.
Other publications
- Dietre, B., Anich, I., Reidl, D., Kappelmeyer, T. and Haas, J. N. (2012). “Erste Hirten und Bauern der Silvretta – Palynologie und Ethnobotanik im Fimbertal und Paznaun”. In: Letzte Jäger, erste Hirten. Hochalpine Archäologie in der Silvretta. Ed. by T. Reitmaier. Archäologie in Graubünden – Sonderheft 1, 237–256.
- Reitmaier, T., Lambers, K., Walser, C., Zingman, I., Haas, J. N., Dietre, B., Reidl, D., Hajdas, I., Nicolussi, K., Kathrein, Y., Naef, L. and Kaiser, T. (2013). Alpine Archäologie in der Silvretta. Archäologie Schweiz 36(1), 4–15.
Read also
- Carrer, F., Colonese, A. C., Lucquin, A., Petersen Guedes, E., Thompson, A., Walsh, K., Reitmaier, T., & Craig, O. E. (2016). Chemical Analysis of Pottery Demonstrates Prehistoric Origin for High-Altitude Alpine Dairying. PLOS ONE, 11(4), e0151442. https://doi.org/10.1371/journal.pone.0151442
Thanks to Jean Nicolas Haas for the featured image at the top of the article.
Bio- and Beta Diversity in Pastures
In summer 2010 I studied with François Gillet (University Bourgogne-Franche-Comté, France) the different components of diversity in pastures from the Jura Mountains. We looked at species richness, beta diversity, and species turnover in two different pastoral vegetation communities, and at different scales, from 0.001 to 1000 m2.
The main conclusions of our work is that the species richness of pastures is log-dependant of the surface, and that this increase in diversity results from the component a of the beta diversity, namely species which are common at two successive plot sizes.
Pollen-Vegetation Relationship
The project’s storyline
Emilie Gauthier (University Bourgogne-Franche-Comté, France) offered to me to take part in a scientific project during my Master studies. The project she designed aimed at investigating the relationships between the actual vegetation of pasture woodlands in the Jura Mountains, and the pollen rain they produce. The objective was to determine to which degree the pollen representation of a vegetation is reliable. This knowledge will in turn help to interpret data from palaeo-records in the region.
With the help of François Gillet (University Bourgogne-Franche-Comté, France), I first made vegetation relevés in several stations, following a forest/pasture gradients. I determined the percentage of cover and Braun-Blanquet indices of each species in 20 x 20 m2 plots. From the same plots, I sampled mosses and dungs. Emilie identified the pollen contained in those samples, and I identified the non-pollen palynomorphs (NPPs), with a particular interest for spores of coprophilous fungi.
Using a redundancy analysis, we found out that the grazing and tree-cover gradients have a significant effect on pollen and NPP assemblages. It suggests that particular taxa can be used as indicators for grazing pressure and tree-cover.
Outcome
The results from this project were presented during the 4th NPP Workshop in Besançon in 2010, and have been published in Review of Palaeobotany and Palynology in 2012.
Dietre B, Gauthier É and Gillet F (2012). Modern pollen rain and fungal spore assemblages from pasture woodlands around Lake Saint-Point (France). Review of Palaeobotany and Palynology 186, 69–89. 10.1016/j.revpalbo.2012.07. 002