Authors: Magurran, Anne;

The world is experiencing a biodiversity crisis with ecosystems under escalating threat as a consequence of anthropogenic pressures on the environment. It is clear that biodiversity is imperilled, but the nature of ongoing biodiversity change is complex, and not well understood. In this talk I will summarise recent advances in documenting temporal and spatial change in biodiversity in terrestrial and aquatic ecosystems. This work shows that these patterns are complex. For example, compositional re-arrangements (change in temporal beta diversity) are widespread. The ecological processes that underpin these changes, and the similarities and differences in how they play out in aquatic and terrestrial systems, are not well understood. I will finish by identifying a number of research challenges including how we can use new approaches to quantifying biodiversity change to deliver fundamental insights into the regulation of ecological communities, and inform strategies to mitigate damage and protect the resilience of these ecosystems.