THURSDAY 15 February 2024, 4 PM CET (Hybrid Webinar)
PROF. ANTONY BROWN
Professor at the University of Tromsø Museum. Geoarchaeologist
PI of the ERC project TerrACE
Abstract:
There is an ongoing revolution in palaeolimnology and palaeoecology with the exponential application of molecular methods, and in particular sedimentary ancient DNA (sedaDNA). Although it was ‘discovered’ some 20 years ago we have only just realized that DNA can, under optimal conditions, be preserved for over 2 m years, and that it can be preserved even in temperate to sub-tropical climates. This opens the way to its potential use in all of Europe, primarily in lacustrine systems, but also wetlands and fluvial systems. Work on lakes has shown that sedaDNA is derived almost exclusively from close to the lake and from influxing rivers and it is not derived from pollen. We still have much to learn about its taphonomy but there is strong evidence that it is preserved only when it is sorbed to/into particles and particularly clay minerals, calcites and possibly organo-metal complexes.
The advantages of sedaDNA over traditional palaeoenvironmental methods, such as pollen, is that it has far higher taxonomic resolution, often to the species level and even potentially below, and that it has a defined source area. An additional, and clinching advantage, is that it can include not only plants (vascular and non-vascular) but also animals including mammals, birds, fish and invertebrates, and even pathogens. This means that theoretically it can be used to reconstruct almost the entire ecosystem near a lake or a non-ombrotrophic wetland. However, due to the taphonomic uncertainties its uptake in fluvial studies has been slower, but excellent sedaDNA records have been derived from palaeochannels and floodplain ponds. This paper will review the potential of sedaDNA in floodplains and highlight the hydroecological questions that it can be used to tackle. Examples will be drawn from recent and ongoing research in the Northern Norway, the UK, and France.