2025-2026 MES/MESc Speaker Series: The effects of long-term climate and fire disturbance on terrestrial-aquatic ecosystem dynamics

Abstract: Climate is the most important driver of aquatic ecosystem change, effecting nutrient status, productivity, and ecosystem health and function. Aquatic ecosystems are affected by two climatic pathways, either directly through change in temperature or lake level, or indirectly via vegetation change, fire disturbance, catchment processes, and soil dynamics which alter aquatic ecosystems. While there is a greater understanding of climate impacts on freshwater systems, and a growing understanding of the complex indirect relationships climate has on these environments; the patterns related to these pathways on longer timescales and larger spatial scales are not particularly well-known. Moreover, wildfires have become an increasing threat to many fire-sensitive ecosystems, with very little knowledge about how fire impacts aquatic systems. Using a series of multiproxy palaeoecological records from Tasmania, Australia and Experimental Lakes Area, Canada, this research aims to understand the complex relationship between climate and fires disturbance on terrestrial-aquatic ecosystem dynamics on long timescales. Radiocarbon, charcoal, pollen, elemental and isotopic carbon and nitrogen, X-Ray Fluorescence, diatoms and cladocera were used to reconstruct the chronology, fire regimes, vegetation change, nutrient dynamics, catchment geochemistry, and aquatic ecological response. Findings show indirect climate pathways are primary driver of terrestrial-aquatic ecosystem change over the Holocene, with some evidence of direct climate influences. Fire is also an important driver of ecosystem change in these systems causing changes in vegetation composition, altering the nutrient profile of soils and increasing erosion and sediment delivery. Resulting in increased pH, disturbance taxa, increased productivity, and lost resilience of the aquatic environment. Climate and wildfires are key drivers of the complex interactions between terrestrial-aquatic ecosystem dynamics. To better anticipate the impacts of anthropogenic climate change and the future threat of wildfires, we need a deeper understanding of how these interconnected systems will respond in future.

Bio: Dr Beck is a newly appointed Assistant Professor in Earth and Environmental Science within the Department of Biology, Chemistry and Geography, specialising in Palaeoecology. She completed her undergraduate and Master degree at the University of Toronto, Canada. Then moved on to the University of Melbourne, Australia to complete a PhD in Geography on the Direct and Indirect Effects of Long-Term Climatic Change on Terrestrial-Aquatic Ecosystem Interactions in Tasmania. In 2018 she was appointed as a Lecturer in Quaternary Science at the University of Lincoln in a new School of Geography. Her primary research interests focus on the influences of long-term climate change and fire disturbance on terrestrial-aquatic ecosystem dynamics.

Link: https://us06web.zoom.us/meeting/register/BRonbuhnQca2KbO-uIFrmQ