Effects of global change on aquatic ecosystem resilience through shifts in community size structure – a modelling approach for better holistic management
Combining new mathematical models with large-scale field data to better understand global change impacts on aquatic ecosystems.
Global change affects lake ecosystems through increasing temperatures, higher load of nutrients and intensive human exploitation. All these pressures lead to changes in body sizes of aquatic organisms. In this project, we will assess the role of size shifts in ecosystem resilience to future global change scenarios by joining theoretical models with field data from Scandinavian lakes.
Global change affects aquatic ecosystems through multiple pressures such as climate warming, eutrophication and overexploitation. One of its hallmarks is a shift in body size, typically towards dominance of small organisms. So far, this aspect has been studied in isolation from its ecosystem consequences, which may obstruct informed management actions. In this project, we address this gap by developing novel size-structured food web models and then using them to predict lake ecosystem resilience to global change pressures. We build mechanistic plankton food web models to study the effects of size shifts on key ecosystem functions. We employ these models to better understand large-scale patterns using data sets on lakes across Sweden. We assess and predict lake resilience to future global change scenarios, thus providing an important tool for better management initiatives. Additionally, we develop physiologically-structured fish population models that consider not only size shifts in fish, but also the dynamics of the entire lake ecosystem down to the nutrient level. We utilize data across Scandinavia to identify lakes most vulnerable to global change, while suggesting better, holistic management actions. The project provides an important stepping-stone towards better integration of theoretical ecology with current practices of population management and ecosystem conservation.