PALEO-AGRI · agroPastoral Activities and effects on Landscapes and ErOsion dynAmics in the alps: a new insight from Geological appRoaches and lake sedIment DNA

agroPastoral Activities and effects on Landscapes and ErOsion dynAmics in the alps:a new insight from Geological appRoaches and lake sedIment DNA

Due to their unique biological and geological resources, mountains have attracted humans since Prehistory, despite their sensitivity to environmental and climatic changes. In the current context of unprecedented speed and amplitude of global changes (climate, pollution, biodiversity decline), the investigation of past human-climate-environment interactions in such significant areas is imperative. Such studies can provide “lessons from the past” when engaging with present and future scenarios: tracing past environmental changes allows us to better understand current conditions as they are, in part, inherited from past successions of climatic change and land use. Few studies, however, have investigated the detailed spatiotemporal dynamic of alpine agrarian activities (including their precise nature) or their impacts on plant cover and erosion. This is largely due to the lack of suitable proxies for human activities in these environments. The PALEO-AGRI project addressed this challenge through the optimisation of an emerging tool, the analysis of extracellular DNA archived in lake sediments (a continuous archive of the past) and soils in archaeological contexts. The design of our project comprised the study of several sites distributed across elevation and latitudinal gradients in the French Alps (Fig. 1). Despite the increasing popularity of sediment DNA studies, almost nothing is known about the taphonomic processes (DNA source, transfer and deposit), which might affect and bias DNA records - WP1 of PALEO-AGRI aimed to address this issue. WP2 focused on the study of archaeological sites in the Ecrins Massif, where appropriate lakes for DNA analyses are missing. The goals of this WP were: 1) to provide information about the past use of the structures that yield very little material culture due to poor preservation conditions, and 2) to assess the legacy of past human activities on the current ecosystem. WP3 focussed on the reconstruction of the spatiotemporal dynamic of agro-pastoral activities and their effects on soil erosion and plant cover.

Data: CORDIS, © European Union