Terrestrial ecosystems are responding to rapid environmental change, but merely observing an ecosystem response does not necessarily reveal the processes responsible for it. Similar changes in carbon uptake, nutrient cycling, plant growth or soil processes can arise from different, interacting mechanisms. With the increasingly detailed information provided by ecosystem monitoring and measurement, a central challenge for ecosystem science arises: how can we use experiments and observations to distinguish different mechanisms, test their consequences, and improve our ability to predict ecosystem change?

This session focuses on approaches that move from documenting ecosystem responses towards identifying and testing the mechanisms that generate them. We welcome studies that combine experiments, observations, data synthesis and modelling to investigate alternative process hypotheses, discriminate between mechanisms, identify missing processes, or constrain model parameters and structure.

Studies may consider responses to elevated CO₂, climate change, altered nutrient availability or combinations of environmental changes, with focus on the mechanisms underlying ecosystem responses rather than on individual global-change drivers.