Benjamin

Climate Change in the Alps

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 ZĂŒrich) 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 fĂŒr 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 JĂ€ger, erste Hirten. Hochalpine ArchĂ€ologie in der Silvretta. Ed. by T. Reitmaier. ArchĂ€ologie in GraubĂŒnden – 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 ArchĂ€ologie in der Silvretta. ArchĂ€ologie 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.

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Bio- and Beta Diversity in Pastures

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.

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Pollen-Vegetation Relationship

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.

Selection of pollen and NPPs found in moss samples in the Jura Mountains, after Dietre et al., 2012.

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

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