From Climatic to Anthropogenic Drivers: A Multi-Proxy Reconstruction of Vegetation and Peatland Development in the French Jura Mountains

Emilie Gauthier,Emilie Gauthier,Vincent E.J Jassey,Vincent E.J Jassey,Vincent E.J Jassey,Richard Payne,Frédéric Delarue,Frédéric Delarue,Frédéric Delarue,Fatima Laggoun-Defarge,Mariusz Lamentowicz,Daniel Gilbert,Daniel Gilbert,Hervé Richard,Hervé Richard,Edward A.D Mitchell

doi:10.3390/quat2040038

Abstract

A 4 m core was extracted from the center of a peatland located in the Drugeon valley (France). Thirteen radiocarbon dates were used to build a robust age model. Testate amoebae were used for reconstructing mire surface wetness. High-resolution pollen analysis of the sequence reconstructed 9 millennia of development of the peatland and its surrounding vegetation. During the early/middle Holocene (9500 to 5800 cal BP), warm conditions led to high evapotranspiration and low water levels. The vegetation history is characterized by the development of a Pinus and a mixed Quercus forest. From 5800 cal BP, testate amoebae show wetter conditions, indicating the onset of the cooler Neoglacial period. The cooling is also evidenced by the development of Abies and Fagus trees, replacing the oak forest. The first indicators of human impact appear at about 4800 cal BP, and indicators of farming activity remains very rare until ca. 2600 cal BP, at the beginning of the Iron Age. The development of the peatland responded to climatic fluctuation until 2600 cal BP, after which human impact became the main driver. The last millennium has been characterized by sudden drying and the spread of pine on the peatland.

Highlights

The Drugeon valley (Figure 1) is a landscape dominated by wet meadows and peatlands at different stages of valley development
It is understand the different stages of development of the peatland and precisely date the first occurrences, possible to understand the different stages of development of the peatland and precisely date the development, anddevelopment, sometimes decline of the main taxa of present in this of theinJura first occurrences, and sometimes decline the main taxapart present this Mountains
This study shows the very good complementarity of pollen and testate amoebae analyses (Figure 5)

Summary

Introduction

The Drugeon valley (Figure 1) is a landscape dominated by wet meadows and peatlands at different stages of valley development.peatlandsdominated with Mountain (Pinus uncinata), such at asThe Drugeon (Figure Wooded1) is a landscape by wetpine meadows and peatlandsForbonnet, are of believed to be the ultimate stage of peatland development the region.different stages development.Wooded peatlands withMountain pine (Pinusinuncinata), suchThe as Forbonnet peatland has been intensively studied for over years, and climatic parameters and soilForbonnet, are believed to be the ultimate stage of peatland development in the region. The Drugeon valley (Figure 1) is a landscape dominated by wet meadows and peatlands at different stages of valley development. Mountain pine (Pinusinuncinata), suchThe as Forbonnet peatland has been intensively studied for over years, and climatic parameters and soil. Forbonnet, are believed to be the ultimate stage of peatland development in the region. The Forbonnet temperature are intensively recorded at a permanent stationparameters [1,2]. Date, no peatland has been studied for over 10 monitoring years, and climatic and soil to temperature comprehensive has been conducted to describe the developmental of this sitestudy sincehas the are recorded at astudy permanent monitoring station [1,2].

Objectives

Methods

Results

Discussion

Conclusion