|
|
|
Topics and sessions > Topic IV - Critical zone and integrated approachesIV-1-Biogeochemical cycles in the subsurface: molecular and mineral proxies for integrated lacustrine studiesConveners
Microorganisms are abundant and diverse in inland waters, where they contribute significantly to global element fluxes through regulation of biogeochemical cycles. Lake sediment accumulation over geologic timescales records past climatic and trophic conditions, forming stratified archives. By regulating sediment biogeochemical cycles, the microbial biosphere hosted in the lacustrine subsurface drives essential feedback in terms of benthic releases or sediment sequestration, with significant potential to influence environmental conditions or alter their sedimentary records. At present, the relationship between lake sediments as microbial habitats and biogeochemical processes in bottom waters, at the sediment-water interface and in the subsurface remain elusive as lakes represent dynamic ecosystems. This session invites contributions investigating microbial processes in lake sediments. It is meant to encompass shallow biogeochemical cycles, as well as deeper, slower processes that lead to long-term organic matter remineralization, mineral dissolution and precipitation, and proxy disturbance. Indicative tools may include molecular-based methods (e.g. nucleic acids, proteins, lipids), isotopic fingerprinting of sediment fractions, biogeochemical modeling, and any integrative approach that bolsters new understanding of biological-geological interactions in lacustrine ecosystems. Early career scientists are particularly welcome to contribute to the session.
IV-2-How can modeling approaches help us to understand past, present and future lakes ? Conveners
This session welcomes all studies based on any modeling approaches which contribute to a better knowledge and understanding of continental hydro-systems, with a focus on (data-sparse) lakes. This session is driven by the curiosity to learn about all existing approaches, from analog experiments to numerical simulations, which help to model hydro-sedimentary processes in lakes, to reconstruct long-term stratigraphic architectures, to test the impact of various parameters on lakes (water quality and salinity, biodiversity and natural habitats, coastal erosion, nutrient or pollutant dispersal, …). This session indifferently concerns both ancient lakes from the geological record and recent to modern lakes, and promotes exploring the future of lakes.
IV-3-Paleolimnological Insights into Carbon Cycling in Lakes Conveners
Lakes are key components of the global carbon cycle, receiving carbon (C) originally fixed by the terrestrial biosphere, which is subsequently buried in sediments or released back to the atmosphere as greenhouse gases. Changes in natural and anthropogenic forcings can impact the flux of terrestrial organic matter to lakes, modify aquatic carbon production, and alter in-lake carbon cycling. Lake sediment records offer a unique, long-term perspective on these processes. This session invites contributions that use lake sediments to explore historical changes in lake carbon cycling, identify the primary drivers behind these changes, and assess their impacts on aquatic ecosystem functioning. We aim to bring together researchers from diverse fields and methodologies, including biological, geochemical, molecular, isotope proxies, and modeling approaches, to provide a comprehensive understanding of past carbon dynamics in lakes.
IV-4-Hydrothermal and groundwater influences on lacustrine sedimentation and paleoecology: A tribute to Michael Rosen Conveners
Lakes in many regions are variably fed by hot springs and geothermal fluids, whether from the lake margins, the lake floor, or within the drainage basin. This is especially true for tectonic and volcanic lake basins. In other locations, particularly in closed basins in semi-arid regions (notably playas and saline pans) and karstic terrains, groundwater may be the primary source of inflow. In both cases, the influence of groundwater recharge may vary seasonally and with climate change. This session aims to explore how hydrothermal fluids and groundwaters affect lake hydrology, hydrochemistry, sedimentation (both physical and chemical), mineralogy and geochemistry, and the biota. A secondary objective is to establish criteria for recognizing their influence in the limnogeological record.
|
