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Topics and sessions > Topic III - Environmental issuesIII-1-Furthering the relationship between palaeolimnology and conservationConveners
Palaeolimnology has a strong track record of successful application to conservation challenges and has proved a useful tool to inform various questions, from species reintroductions to habitat management and restoration. Despite this, there remains a disconnect between conservation practitioners and palaeolimnologists, leading to missed opportunities for better integration where the synergies of working together could lead to better environmental outcomes. We invite researchers to share best practice and case studies of co-produced research where palaeolimnology has been used to directly inform conservation practice, and the divide between research and practice has been successfully bridged. These case studies will be used to better understand best practice for collaboration and provide guidance for improved palaeo-conservation integration.
III-2-Using lake sediments to trace soil health and agricultural practices across watershedsConveners
Human activities over the past centuries, particularly since the "Great Acceleration" period, have driven rapid environmental changes, transforming ecosystems and accelerating soil degradation. Soils play a fundamental role in food security, water quality, and climate regulation by sequestering carbon, while lakes can preserve continuous sediment records that serve as environmental archives for reconstructing soil changes over time. We encourage studies that combine sediment and soil analyses to investigate factors such as nutrient imbalances, contaminants dynamics (e.g., PTEs, PAHs, pesticides, and microplastics), and land-use changes (e.g. deforestation, agriculture expansion) that impact soil quality. At the watershed scale, researchers will present insights on the speed and scale of soil quality changes, patterns of soil erosion recorded in lake sediments, and the potential delayed response of water bodies within watersheds – findings that are essential for the critical zone community. This session will allow to connect sediment records with soil, document landscapes changes through the Holocene to the present day and emphasize the need for sustainable land management practices to preserve soil health.
III-3-Reconstructing the impact of human activities on the environmentConveners
In the context of rapid anthropogenic global changes, understanding, characterising and quantifying the impact of human activities on the environment has become a major preoccupation of the geosciences community in recent years. To this end, the use of natural archives spanning centuries or millennia, such as those from lake sediments, is becoming increasingly popular. Such a retrospective approach makes it possible to observe baseline conditions, as well as the trajectories and history of climatic and human forcings, which are the main factors affecting the environment during the Holocene. Although several studies have attempted to distinguish between the effects of climate and human activities, very few have succeeded in doing so, as these effects often occur concomitantly over the last few thousand years (reviewed by Mills et al. 2017). Among other effects, human activities can cause increased soil erosion, pollution, changes to habitats and the introduction of species (reviewed by Dubois et al. 2018). In order to develop appropriate responses to these changes to preserve sustainability of ecosystem services, it is essential to increase the number of relevant long-term studies throughout the world. The aim of this session is to bring together researchers working on characterising and quantifying the effects of human activities on the environment through the use of sediment archives from lake and other aquatic systems (ponds, wetlands, coasts). We welcome presentations that contribute to advancing our understanding of this subject, covering all or part of the Holocene, whatever the location and type of impact tracked. We hope to be able to present an array of many different approaches and proxies, reflecting the mission of the PAGES Human Traces working group (https://pastglobalchanges.org/science/wg/human-traces/intro). Early career scientists are particularly encouraged to submit abstracts. References: Dubois, N., Saulnier-Talbot, É., Mills, K., Gell, P., Battarbee, R., Bennion, H., ... & Valero-Garcés, B. (2018). First human impacts and responses of aquatic systems: A review of palaeolimnological records from around the world. The Anthropocene Review, 5(1), 28-68. Mills, K., Schillereff, D., Saulnier‐Talbot, É., Gell, P., Anderson, N. J., Arnaud, F., ... & Ryves, D. B. (2017). Deciphering long‐term records of natural variability and human impact as recorded in lake sediments: a palaeolimnological puzzle. Wiley Interdisciplinary Reviews: Water, 4(2), e1195.
III-4-Tracing anthropogenic contamination in lake sediments: novel methods and applicationsConveners
Current developments in analytical techniques have provided novel insight into determining chemicals of concern at trace levels in lake sediments. These compounds and their transformation products contain information about the sources, transport across ecosystem compartments, and sinks in sediments through time. This session invites contributions exploring methods and applications of novel analytical techniques (e.g., LC/GC-MS/MS, 2D-GC-MS, HR-MS, MALDI-Imaging-MS), data processing, statistical analysis and data mining of potentially harmful organic and inorganic, natural and synthetic compounds, including legacy and emerging organic micropollutants, heavy metals, and other contaminants. We also welcome contributions from process studies, ecotoxicological risk assessments, and remediation of contaminated lake systems. The session covers instrumental, historical, and prehistorical times.
III-5-Resilience and recovery in lake systems across time and spaceConveners
Lake ecosystems provide many key services, including food and water security, biodiversity, and carbon storage. These systems are highly susceptible to anthropogenic and natural drivers of stress, such as pollution, over-extraction, and climate change. A range of metrics and studies demonstrate lake ecosystems as one of the most vulnerable ecosystems globally. Recent studies have further indicated many lake ecosystems are approaching, or have passed, thresholds to unhealthy states, creating urgency for the development of well-informed management or restoration plans. Recovery from degraded states is often impeded by hysteresis and the influence of multiple stressors. Pathways to recovery remain largely unknown. Furthermore, there are limited systematic solutions for lake recovery reaching a structurally resilient state, hence, new research in this field could benefit freshwater health and ecosystem management. Here, we invite presentations analysing lake ecosystem resilience and recovery pathways.
III-6-Inferring the Past Drivers and Consequences of Lake Eutrophication in Modern and Ancient SocietiesConveners
Human-mediated landscape alterations, e.g., agricultural development and urbanization, can drive changes in limnological conditions of nearby lakes, often causing eutrophication and its attendant consequences - algae/cyanobacteria blooms, toxin production, and regime shifts. Many lakes are currently experiencing profound limnological changes, but the onset of hypereutrophy and harmful algal blooms (HABs) seen in many waterbodies today may be linked to past periods of landscape alteration, caused by climate changes and/or human disturbances that predate limnological monitoring efforts. This session will focus on the role of past landscape disturbances and how such perturbations served as drivers of changing lake trophic state. Paleolimnological records across all timescales and periods of historic/prehistoric human disturbance will be welcome in the session. Inferred limnological conditions from pre-disturbance periods are required to set realistic lake management targets, i.e., conditions that are expected following the decline or complete removal of nutrient subsidies caused by human agency. We invite poster and oral presentations on studies that have employed proxy variables for lake trophic status found in lacustrine sediments (e.g., element chemistry, stable isotopes, organic molecules [pigments, toxins], diatoms, cladocerans, chironomids, etc.), especially investigations that were also undertaken to identify human-mediated stressors on the landscape that caused past lake trophic state shifts.
III-7-The coevolution of environments and biodiversityConveners
Understanding the interplay between biodiversity and environmental change is essential for predicting future ecosystem change. The proposed session will explore the coevolution of environmental conditions and biodiversity at the ecosystem scale. With climate change and ecosystem degradation leading to the loss of biodiversity and ecosystem functioning, it is crucial to co-examine past environments and assemblages at the whole ecosystem scale. We invite submissions that address how past climatic and environmental change may drive shifts in community structure, diversity, and trophic interactions by focusing on the cross-habitat integration afforded by sediment archives. We encourage contributions from diverse disciplines that harness a wide range of traditional and emerging approaches to foster interdisciplinary discussions and innovative analyses that allow for more precise reconstructions of past environmental conditions and biodiversity changes.
III-8-Anthropocene lake ecosystem dynamics in fast-changing AsiaConveners
As the fastest developing region in the world, Asia has experienced unprecedented social-ecological transformations, exhibiting trajectories that are typical of the Anthropocene Great Acceleration. Lakes in the floodplains, mountains and plateaus are confronting multiple anthropogenic stressors as well as their complex interactions, potentially threatening water security, biodiversity and regional sustainable development. Improved understanding of the long-term lake-watershed system changes in Asia can significantly contribute to constructing the framework of Anthropocene research. This session seeks to facilitate discussions on lake ecosystem dynamics in Asia and the implications for Anthropocene, particularly referring to the trajectories, tipping points and regime shifts, and the nature and magnitude of human impacts. We welcome theoretical and empirical studies from diverse geographical contexts, demonstrating how multi-proxy (paleo)limnological data, either independently or in conjunction with other disciplines, improves our understanding of human-environment interactions in the Anthropocene.
III-9-Pollen-based land cover reconstruction to study climate and human impact on vegetation, terrestrial and aquatic ecosystemsConveners
The combination of climate variations and human activities, especially agro-pastoral practices, have significantly influenced terrestrial and aquatic environments, over time. Changes in climate (e.g. humidity, temperature, seasonality) and land use (e.g. deforestation, agriculture, fire) have accelerated soil erosion and altered socio-ecosystems by disrupting vegetation and ecological balance. Pollen assemblages from lake and bog sediments are valuable proxies for assessing past vegetation. Advanced pollen-based modeling techniques now correct biases in inter-taxonomic differences in pollen production and dispersal, enabling more accurate reconstructions of past vegetation and land cover at regional to local scales. These reconstructions, combined with other proxies (e.g. spores of coprophilous fungi, NPP, charcoal, environmental DNA, GDGTs), offer valuable insights into how climate and land use have shaped landscapes and influenced environmental processes over time. This session will explore pollen/NPP-based analyses for examining long-term changes in land cover, with an emphasis on the interactions between climate/human activities and shifts in past vegetation and land cover. Studies that focus on spatially explicit reconstructions of past land cover are encouraged. Approaches that investigate the relationship between changes in vegetation, climate, land cover, and their impacts on terrestrial and aquatic ecosystems, as well as erosion dynamics, are also welcome.
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