C. Giguet-Covex

The University of York · Departement of Archaeology

Flooding is a pervasive natural hazard—costly in both human and economic terms—and climate change will probably exacerbate risks around the world. Mountainous areas, such as the densely populated European Alps, are of particular concern as topography and atmospheric conditions can result in large and sudden floods. In addition, the Alps are experie...

Watersheds of large peri-alpine lakes have undergone substantial demographic and urban developments (leading to the release of waste waters, containing nitrates and phosphates), as well as agricultural activities intensification (use of fertilizers) during the 20th century. The seasonal fluctuations of their water levels is often reduced and contro...

Locations of sampling sites from sedimentary ancient environmental DNA (aeDNA) studies. aeDNA is DNA that has degraded into short fragments, exhibits post-mortem damage signatures, and is recovered from a non-living tissue, organism, or environmental sample. Here we focus on sedimentary archives with contiguous records such as lake and marine sedim...

The trajectories of mountain socio-ecosystems are complex and influenced by numerous factors (climate, human practices, slope, etc.). This study combined methods used in palynology, ecology and history to produce complementary data to improve understanding of the trajectories of an alpine socio-ecosystem over the last 500 years. Past changes in veg...

Over the last two millennia, European Alpine ecosystems have experienced major changes in response to the important, yet fluctuating, impact of human activities. This study aims to reconstruct the environmental history of the last 1800 years on the western edge of the Alps by analyzing sediments from Lake Aiguebelette, a large lake located in the p...

Flooding is a pervasive natural hazard—costly in both human and economic terms—and climate change will probably exacerbate risks around the world. Mountainous areas, such as the densely populated European Alps, are of particular concern as topography and atmospheric conditions can result in large and sudden floods. In addition, the Alps are experie...

Lake sediments are a valuable archive to document past flood occurrence and magnitude, and their evolution over centuries to millennia. This information has the potential to greatly im-prove current flood design and risk assessment approaches, which are hampered by the shortness and scarcity of gauge records. For this reason, paleoflood hydrology f...

PaleoEcoGen is a new working group that was launched with the aim of bringing together scientists from around the world who use ancient environmental DNA (ancient eDNA) as a novel proxy to examine the response of past biological communities to environmental changes (pastglobalchanges.org/paleoecogen). We are particularly interested in exploiting th...

Since the seminal paper in 1998 (Coolen and Overmann), sedimentary ancient DNA (sedaDNA) has become a powerful tool in paleoecology to reconstruct past changes in terrestrial and aquatic biodiversity. Still, sedaDNA is an emerging tool and there is a need for calibrations and validations to ensure the reliability of sedaDNA as a proxy to reconstruc...

The use of lake sedimentary DNA to track the long-term changes in both terrestrial and aquatic biota is a rapidly advancing field in paleoecological research. Although largely applied nowadays, knowledge gaps remain in this field and there is therefore still research to be conducted to ensure the reliability of the sedimentary DNA signal. Building...

eDNA refers to DNA extracted from an environmental sample with the goal of identifying the occurrence of past or current biological communities in aquatic and terrestrial environments. However, there is currently a lack of knowledge regarding the soil memory effect and its potential impact on lake sediment eDnA records. to investigate this issue, t...

Sediments of Lake Paravani, the largest natural lake in the South Caucasus, were analysed to reconstruct the millennial history of the environment. Pollen analysis, previously undertaken on the first core retrieved in the middle of the lake, revealed a vegetation history for the last 12 millennia. As part of the present study, a new core was taken...

Over the past decade, an increasing number of studies has used environmental DNA from lake sediments to trace past lake ecosystem and landscape changes, agricultural activities or human presence and more broadly the biodiversity. In the environment, DNA can be found as intracellular and extracellular DNA (iDNA and exDNA). The contribution of each o...

Natural organic matter in soils contains stable semiquinone radicals, the nature of which depends on their origin and their maturation state. The relative proportions of these radicals, deduced from simulations of the EPR spectrum, constitute a signature which can be used to differentiate soils and even their horizons. It allows us to monitor the t...

The study of sediment cores allows for the reconstruction of past climate and environment through physical- chemical analysis. Nevertheless, this interpretation suffers from many drawbacks that can be overcome with the newest technologies. Hyperspectral imaging is one of these and allows a fast, high resolution, and non- destructive analysis of sed...

Soil erosion is strongly linked to both precipitation patterns and land-use. We examine the effects of erosion and its drivers (i.e. human or/and climate) on soil evolution from the study of lacustrine archives in the northern French Alps. Multi-proxy analyses of the Lake Gers sediment sequence combined with the study of soils and rocks of its catc...

Over the last decade, an increasing number of studies have used lake sediment DNA to trace past landscape changes, agricultural activities or human presence. However, the processes responsible for lake sediment formation and sediment properties might affect DNA records via taphonomic and analytical processes. It is crucial to understand these proce...

Session for EAA 2019 in Bern

For ecological and economic issues, evaluating the environmental fate of dissolved and suspended matter in catchments and river ecosystems still remains a challenge for the preservation and management of natural resources. Models are useful tools and may help to cope with this challenge, and especially to define the relationships between the state...

Tropical forests shelter an unparalleled biological diversity. The relative influence of environmental selection (i.e. abiotic conditions, biotic interactions) and stochastic‐distance dependent neutral processes (i.e. demography, dispersal) in shaping communities has been extensively studied for various organisms, but has rarely been explored acros...

Until now, sedimentary DNA (sedDNA) studies have only focused on cold and temperate regions were DNA is relatively well preserved. Consequently, the tropics, where vegetation is hyperdiverse and natural archives are rare, have been neglected and deserve attention. In this study, we used next-generation sequencing to barcode sedDNA from Lake Sele, l...

The relative influence of deterministic niche-based (i.e. abiotic conditions, biotic interactions) and stochastic-distance dependent neutral processes (i.e. demography, dispersal) in shaping communities has been extensively studied for various organisms, but is far less explored jointly across the tree of life, in particular in soil environments. H...

Soils have a substantial role in the environment because they provide several ecosystem services such as food supply or carbon storage. Agricultural practices can modify soil properties and soil evolution processes, hence threatening these services. These modifications are poorly studied, and the resilience/adaptation times of soils to disruptions...

During the last decade, an increasing number of studies were interested in the use of lake sediment DNA to trace past landscape changes (plant DNA), agricultural activities (plant, mammal and bacteria DNA) as well as the human presence (human-speci c bacteria DNA). However, as all sedimentologists know, the sedimentation in a lake can vary tem- por...

Soils have a substantial role in the environment because they provide several ecosystem services such as food supply or carbon storage. Agricultural practices can modify soil properties and soil evolution processes, hence threatening these services. These modifications are poorly studied, and the resilience/adaptation times of soils to disruptions...

Au cours de la dernière quinzaine d’années, nous nous sommes attachés à ” faire parler ” les sédiments des lacs alpins afin de reconstituer les changements environnementaux qui ont ponctué le cours de l’interglaciaire dans lequel nous vivons : l’Holocène. Largement inspirés par les méthodes développées en paléocéanographie, nous avons pour cela dév...

Varved lake sediments provide opportunities for high-resolution paleolimnological investigations that may extend monitoring surveys in order to target priority management actions under climate warming. This paper provides the synthesis of an international research program relying on >150 years-long, varved records for three managed perialpine lakes...

Varved lake sediments provide opportunities for high-resolution paleolimnological investigations that may extend monitoring surveys in order to target priority management actions under climate warming. This paper provides the synthesis of an international research program relying on >150 years-long, varved records for three managed perialpine lakes...

Paleoenvironmental studies are essential to understand biodiversity changes over long timescales and to assess the relative importance of anthropogenic and environmental factors. Sedimentary ancient DNA (sedaDNA) is an emerging tool in the field of paleoecology and has proven to be a complementary approach to the use of pollen and macroremains for...

Paleoenvironmental studies provides crucial long-term data to study both anthropogenic disturbance and/or climate changes, and their effects on the environment. We used a multi-disciplinary approach to reconstruct past landscapes in Lake Anterne watershed (Haute-Savoie, French Alps) over the Holocene. In a previous study, DNA metabarcoding approach...

Extreme precipitation events can trigger floods that may have serious human and economic consequences. The flood represents extreme rainfall event, which in high altitude mountain regions are mostly triggered alternatively by local convective summer storms or, less frequently, by regional widespread rainfall event. The former’s precipitation patter...

L'article proposé ici présente les résultats d'un outil en plein essor, l'ADN sédimentaire lacustre appliqué à la reconstitution de l'histoire des activités agricoles et des paysages (ADN des plantes et des mammifères) dans les Alpes françaises. étant donné le caractère novateur de l'outil, une partie de l'article est aussi consacrée à une réflexio...

L'article proposé ici présente les résultats d'un outil en plein essor, l'ADN sédimentaire lacustre appliqué à la reconstitution de l'histoire des activités agricoles et des paysages (ADN des plantes et des mammifères) dans les Alpes françaises. étant donné le caractère novateur de l'outil, une partie de l'article est aussi consacrée à une réflexio...

This article aims to introduce the research presented in this volume of the Collection EDYTEM. The different papers come from a common scientific meeting between soil scientists of the French Soil Science Society (AFES) and organic geochemists of FROG. These articles seem to indicate a renewal of the approaches, issues and methods of study on the e...

Environmental DNA (eDNA) metabarcoding is increasingly used to study present and past biodiversity. eDNA analyses often rely on amplification of very small quantities or degraded DNA. To avoid missing detection of taxa that are actually present (false negatives), multiple extractions and amplifications of the same samples are often performed. Howev...

We present the transposition of an innovative ecological tool, DNA metabarcoding, to paleosciences in the aim of reconstructing past vegetation dynamics and agro-pastoral activities in relation with the evolution of erosion patterns in Alpine areas. DNA metabarcoding was applied on extra-cellular DNA from mammals (mitochondrial DNA) and plants (chl...

In this paper we present a review of a ca. 10-years research effort (1-9) aiming at reconstructing floods dynamics in in French Alps through the Holocene, based on lake sediment records. We will particularly discuss how such geological records can be considered as representative of past climate. This implies a wise interpretation of data in order t...

A high-resolution sedimentological study of Lake Bourget was conducted to reconstruct the flood frequency and intensity (or magnitude) in the area over the last 350 years. Particular emphasis was placed on investigating the spatio-temporal distribution of flood deposits in this large lake basin. The thicknesses of deposits resulting from 30 flood e...

The reconstruction of human-driven, Earth-shaping dynamics is important for understanding past human/environment interactions and for helping human societies that currently face global changes. However, it is often challenging to distinguish the effects of the climate from human activities on environmental changes. Here we evaluate an approach base...

High-altitude lakes are vulnerable ecosystems that require protection and sustainability management, although their overallfunctioning is still poorly understood. In France protected area managers and scientists are cooperating to address this problem.Their results show the huge diversity of these altitude lakes and imply specificities in their fun...

The Research program Pygmalion consisted in 4-years long unprecedented scientific effort to investigate complex human-climate-environment interactions in Northern French Alps. Thanks to a wide geographic cover, it led to evidencing an erosion anomaly at the time of the Allobroges Gallic tribe just prior and after their embedment into the Roman Empi...

L’homme est aujourd’hui reconnu comme un agent géologique majeur en raison des impacts multiples de ses activités sur les différents compartiments du système Terre1. Son empreinte sur l’environnement s’est considérablement accentuée il y a 10 000 à 7 000 ans avec la généralisation de l’agro-pastroralisme. De nombreuses études ont été éffectuées à p...

The aim of this study is to investigate phosphorus (P) species modifications triggered by soil genesis and mountain ecosystem development after glacial retreat using a lake sediment archive (Lake Anterne, North French Alps). Five lake sediment samples, representative of different stages of soil and ecosystem development, were selected for P speciat...

Flood hazard is expected to increase in the context of global warming. However, long time-series of climate and gauge data at high-elevation are too sparse to assess reliably the rate of recurrence of such events in mountain areas. Here paleolimnological techniques were used to assess the evolution of frequency and magnitude of flash flood events i...

The spatiotemporal distribution of biochemical varves spanning the last 150 yr was investigated using 40 cores collected over a depth gradient in a large subalpine lake—Lake Bourget—in the French Alps. Four-dimensional sedimentological, biological, and geochemical analyses show that varve preservation can be used as a reliable proxy to reconstruct...

High-altitude lakes are vulnerable ecosystems that require protection and sustainability management, although their overall functioning is still poorly understood. In France protected area managers and scientists are cooperating to address this problem. Their results show the huge diversity of these altitude lakes and imply specificities in their f...

We present the transposition of an innovative ecological tool, DNA barcoding (Valentini et al., 2009), to paleosciences in the aim of reconstructing past vegetation dynamics and human land-use in relation with the evolution of erosion patterns in Alpine areas. DNA barcoding was applied on extra-cellular DNA from mammals (mitochondrial DNA) and plan...

Mountains are occupied by human societies for a long time. These societies strongly interact with their environment through effects of climate on human occupations and in return anthropogenic impacts on environment. Because lake sediments trap products of erosion, they are interesting archives of past environmental changes. However, due to complex...

The response of lacustrine ecosystems to global warming and human activities in high altitude areas are poorly documented. Nevertheless, fish introductions, grazing activities, atmospheric pollution (nitrogen) and global warming could have affected the ecological functioning of these lakes through nutrient inputs, modifications of biological cycles...

Two well-dated ca Holocene-long sedimentary sequences from deepest parts of Lake Bourget provide new insights onto the evolution of erosion patterns at a regional scale in NW European Alps. The combination of high resolution geochemistry - XRF core scanning, calibrated by 150 punctual measurements - and isotope geochemistry (ɛNd) of the terrigenous...