Predicting ecosystem-level responses to climate change

Climate change is causing biodiversity loss at unprecedented rates threatening ecological stability and human welfare. Freshwater ecosystems (e.g. ponds, lakes, rivers) are particularly vulnerable since species’ potential responses to climate change (e.g. warming, drought) are constrained by the relatively discrete boundaries of these ecosystems. Predicting such responses remains a challenge because most research is still focused on individual species and rarely generalized across different scales and climatic conditions. To advance our understanding on how natural systems respond to climate change it is crucial to find ways to reconcile research at individual, community and ecosystem-level. Eco-physiological studies measuring how organisms adapt to environmental conditions have demonstrated the crucial role of temperature in constraining species distributions. Ecological networks, such as aquatic food webs, are reorganizing as a result of such distributional shifts. In particular, increased temperatures have negative impacts on higher trophic levels (e.g. predatory fish) with cascading effects on food-web structure (e.g. “what-eats-what”) and vital ecosystem services (e.g. detrital decomposition, carbon sequestration). The potential loss of higher trophic levels is particularly crucial in freshwater systems since it can enhance greenhouse gas (GHG) emissions (e.g. CO2, CH4), leading to further global warming (>20% of global CH4 emissions originate in freshwater systems). However, the relationship between food-web structure and GHG emissions is not well understood, particularly in the context of climate change. Unravelling the links between changes in food web structure and GHG emissions is critical to be able to predict how aquatic ecosystems respond to change, but also how much they are contributing to such change. AdaptAlentejo – Predicting ecosystem-level responses to climate change – will address this gap in knowledge by combining multiple disciplines (physiology, biogeochemistry, geophysics) and state-of-art tools (metagenomics, ecological networks, carbon flux measurements). Specific objectives include: (1) Quantify species’ physiological responses to increasing temperatures; (2) Quantify energy flows within aquatic food webs; (3) Test ecosystem-level responses using biodiversity surveys; experimental mesocosms and whole-ecosystem (i.e. reservoirs) manipulations. AdaptAlentejo will use the Guadiana basin (Portugal), and the Europe’s largest artificial water reservoir network – Alqueva – as a case study. AdaptAlentejo brings together an international interdisciplinary team coordinated by an early-career ecologist, Miguel Matias, with experience in theoretical, empirical and experimental approaches in aquatic biodiversity research and, Miguel B. Araújo a leading expert in biodiversity modelling and climate change. AdaptAlentejo partners with EDIA and the Alqueva Multi-purpose Undertaking Infrastructure to link state-of-art research with decision-making processes (i.e. risk assessment, mitigation and/or prevention) in response to future environmental changes.